The Suspension Setup Thread

[sr_rolla]

THIS THREAD APPLIES MAINLY TO SETUP OF A GRIP CAR BUT SOME THINGS DISCUSSED CAN APPLY TO DRIFT ALSO

I've spent a bit of time looking through the different suspension related topics on ae86dc and Ive notice that nobody has accually posted much good info up on why things do what they do. Every body seems to put up posts along the lines of "use cut down falcon springs and suzuki seirra front shock and you'll be sweet" nothing about what real effect this has on the vehicle just that thats what you need to do. As such i thought it would be a good idea to start a thread to educate people on how and why suspension systems do what they do and hopefully save people some time and money in the process.

so...

1) a really common one i've noticed on here is that nobody seems to leave room for droop, a car need droop (the amount that the suspension hangs from static height) in the suspension system, whatever that system is, having zero droop will cause the car to be excessively bumpy and destroy shocks and other components. The wheels can only rise towards the vehicle but not fall away at all, so when the u go thru a dip of any sort, the whole car drops into it and gets hammered on the way out of said dip. In a racing/drifting/fast street circumstance, when you go through a corner, say a left, the right side of the the car should compress and the left should extend. With no droop, the right will still compress but the left will not and the car will hang wheels in the air. Whilst this may look cool, if the wheels are in the air the tyres cannot provide grip. A good amount of droop, no matter what the car or what the hieght is 2-3.5inches

2) Lower is not always better, all cars, the aim should be to get the suspension arms/links/whatever parrallel with the ground to get the most balanced roll centers, or as close to it as possible. This is what RCA's correct on the front of ae's and ke's are for. If the arms are at to great an angle from parrallel (this goes for raising or lowering) the roll centers get out of whack and the car then suffers front bumpsteer and general poor handling characteristics.

3)bumpsteer, This i caused when the LCA and the tie rod end run at different arcs in there travel and cause toe change, wheather by a + or - no. this causes stability issues under heavy braking mainly but all through the suspension range in some cases (see datsun 1600). With standard hieght cars, if any bumpsteer occurs it is usually out of the normal range of suspension travel and can't be felt. On a lowered car it is genrally fixed by raising or lowering the tie rod end mounting position or movung the rack mounts, theoreticly, it could be fixed by modifying the steering links so that they all run on the same radius. KE70's and AE86's VERY RARELY will get bump steer. What is normally felt on a ae or ke that is confused with bumpsteer is...

4)Incorrect scrub radius, to picture this, run an imaginary line from the top of your front shock through your ball joint and onto the ground with the car at static height, front the front. Now on a KE/AE, most of the front tyre will be outside this line, what this causes is whenever u hit a bump, instead of just going over it, your wheel will be pushed back around the axis of your strut, which u feel as steering through your hand. Newer vehicles (with newer strut designs) do not experience this as much as AE/KE's due to a better scrub radius. I personally think that this may have something to do with the front end vibration several KE/AE's get at around 80kp/h. There are ways to fix this but they generally cause several other issues that are much harder to deal with, You now know what the feeling is, deal with it rolleyes.gif

5) cars can be to stiff, jap drifters/circuit cars are way to stiff, they have access to circuits and even streets that are pool table smooth, we don't, run softer settings and go faster. Have a look at the gent on this site that has the valvoline sponsored ae86, his car has plenty of body roll, why? because it is needed to make the tyres work. If you don't run slicks, you don't need stupid spring rates (drifters may not apply here).

6)negative camber, massive neg. will not neccessarally make your car handle better, if you don't have enough grip in your tyres to cause the tyre to roll onto its face in a corner then you have to much neg, simple as that (drifters may be different here) a road tyre cannot deal with massive neg and it will slide/understeer. Circuit style camber designed fro slick tyres will not work with a road tyre. It causes poor stability and poor braking due to a reduced contact patch (running 185's stretched over a 8 inch rim whilst looking cool, does not help this eather)

7)caster, in laymans terms, this is camber that happens when you turn, both front wheels lean over during a turn due to the strut being pulled forward at the bottom or rearward at the top in a static position. On a street car this is more effective than negative camber in creating grip in a corner without regularly destroying tyres due to neg. However exccessive caster can cause high speed instability.

8)track, a wider track does not neccesseraly mean a better handleing car, AE/KE's are blessed with a near on perfect wheelbase from factory (again drift may be different here) of length = 1.7xwidth. Massive track can make the car overly square and when done by using massive offset wheels, causes more problems with scrub radius as discussed before.

Understeer/oversteer, in laymans terms, oversteer is when the tail kicks out, understeer is when the front slides and tends to go straight ahead instead of turning. generally, understeer scares the driver and oversteer scares the shit out of the passengers. In alot of cases over/understeer is caused by factory wheel alignment settings or wrong spring and swaybar settings.

Rollcenters, as a car goes through a corner, it will lean, the inside of the car will extend and the outside will compress its supension. If you could picture an imaginary point about which the car rotates, this is the roll center. Rollcenters can be changed depending on suspension types but the best way to measure change is on a track. Making a sprinter have adjustable rollcenters is not overly difficult, we all know about front roll center adjusters and having several different thicknesses of rca will alow you to try different settings. The pic below shows how to work out front roll centers, this must be done on both sides to find the actual rollcenter where the lower lines intersect. As pictured, changing the angle of the strut or the track will effect the roll center but changing the angle at which the LCA sits will cause the most change. Now generally speaking, raising the roll center will cause more roll, lowering it will cause less. However, having no roll means that the cannot roll onto its tyres and will understeer, having it to high will cause the car to roll over to much and also cause understeer. A sweet spot must be found through testing of the car. There is no right or wrong here as different ride hieghts and driving styles will mean different sized RCA's.
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For the rear it gets more complicated as the angle of the 4 link bars from front to rear has a bearing on the roll center as shown in the 1st pic below and much like the front, rear roll centers are dependant on driving style, horsepower levels, and ride height. the easiest way to make the rear system work properly is to make the 4 link bars equal length, parrallel with each other and the ground. This dials out all roll steer and as shown in the 2nd pic below, makes them no longer a factor in roll centers. Once this is done then a panard bar arrangment that can be moved up and down at both ends, or an adjustable watts linkage setup, can be used to adjust rear roll centers. The only other thing to remember when running a panard bar is that if the bar is not parallel with the ground (as in both end mounts are an even distance from the ground) the roll center will move left to right with suspension movement, it will also change to a different location between left and right corners, and cause left/right diff movement through suspension travel. Again there is no right or wrong here, a high hp car may run a higher roll center in the rear to force the cars weight onto the drive wheel in a corner and provide better drive where as a drifter might run a really low rear roll center so that the rears don't load up and cause eccesive grip or tyre wear.
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Roll steer, i know there are other terms for this but its the term in using for this topic, roll steer is steering of the car through the rear wheels when the car leans through a turn, this is built into factory cars to induce understeer so grandma can get to the shops safely, not so good for us revheads. It is usually caused by having a setup that causes the diff to turn in relation to the car, in the case of sprinters, it is caused by having shorter upper arms in the rear 4link arrangement. Because the upper and lower arms have a different radius of movement when the suspension moves up and down, it causes the top mounts of the diff to be pulled foward on compression and pushed rearward (to a point) on extention, when the car is driving straight, this causes pinion angle change caused by the diff twisting, in a corner, 1 side is compressing and 1 side is extending so, its causes 1 side to be pulled foward and the other side to be pushed rearward. This is how the rear steering effect is caused. While most of this effect can be dialled out using swaybar/spring and shock settings, the only way to properly correct this is by running equal length 4 link bars, in doing this you effectivly lose your rear seats. It really depends on what you want more, rear passengers or proper handling.

Pinion angle, this is the angle that the diff sits at front to rear. there is alot of argument over what the right pinion angle should be, for a traction setup, it should be a 0 degrees when the car is under heavy acceleration, that means that at rest, the diff should be angled slightly downward so that when the nose of the diff tries to rise under acceleration, the diff twists up to straight. The amount that the diff needs to be angled downward depends mainly on what bushes you are running, if they are spherical bearings (rose joints, pillow balls, rod end, heim joints etc) there will be littl or no movement so a lesser angle will be required as opposed to rubber or poly bushes.

Ackerman Effect, Basically speaking, imagine u are on a go-kart, when you turn the wheel full lock the inner wheel turns more than the outer wheels, this is a good example of ackerman effect. Ackerman effect is the toe change that occurs when turning, every car has this designed into it from factory, without ackerman the car wouldn't turn very well at all, it can be effected by either the steering arm angles or moving the steering rack for/aft in the car. DO NOT fuck with ackerman effects, it can cause all sorts of troubles and is very hard to accurately test, don't touch, just try and keep it as close to stock as is humanly possible by making sure that you don't move the rack forward/backwards and you don't change the steering arms without checking that the ackerman is not effected by the change.

Tyres, tyres need movement, fullstop, if you don't have any sidewall flex or tread deflection the tyres can't work properly, whilst a 185 stretched over an 8-9 inch rim looks cool, its wont provide proper grip. A near solid tyre with no sidewall flex will slide and is great for drift but on the curcuit it will not provide proper grip and on the street it is dangerous. Tyres are not just cheap, black round things for burnouts, they can provide a massive amount of information about what the car is doing and what may be wrong with a given setup. Next time your at a circuit meeting, talk to a race tyre technician, he will be able to explain what can be done with a depth indicator, temp gauge your eyes and hands. One of the few things of the top of my head that can be measured easily is camber setting effectivness. If you have access to 1 of those infared termometer guns, borrow it and go for a hard hills run or track day. Use the heat gun to measure the inside and outside temps of a given tyre, say right front. If the outside of the tyre is very hot and the inside is cool then more negative camber must be added, if the outside is cool and the inside hot then you have to much neg. simple as that. I will be adding more here soon.

Aero aids, aerodynamic aids at road speed really are mostly a waste of time, however, having a front spoiler that is as low to the ground as is practically/legally possible will stop air getting under the car and aid high speed stability. Most rear wings are a waste of time, they do not genrally provide downforce unless they are higher than the roofline as if the are within the frontal area of the car the wing will pass over them (there are exceptions to the rule). However, if a rear wing is designed more like the TRD ducktail style rear wing, the flow of air off the rear of the car is interupted and the turbulence that normally happens at the edge of the bootlid, happens further back and causes the vehicle to be more stable.

As was noted on a different forum, some of the pics in here have been taken from fred puhns how to make your car handle, credit where credits due and all that jazz.

ill edit post when i think of more and have more time, thats it for now though.
feel free to voice your opinions.

constructive critisism and debate will be noted and or discussed, flaming will be ignored.

[sr_rolla]

(quote old thread ae71)

i wouldn't disagree with any of that.

good to see more about the proper side of things (grip hehe).

any suggestions on maintaining front stroke with a massively low car, mainly the front?

i have a few theories but want someone do discuss them with.

also having really short rear sucks, i have 1" at most travel from normal hight to full extension, i need longer shocks, but they do keep the springs captive

[sr_rolla]

(quote konakid old thread)

don't have the car 'massively low' perhaps?

[sr_rolla]

(quote old thread ae71)

well i want to maintain a low stance, if i manage to get a little more clearance on the exhaust i can go a tad lower on the front and a little more on the rear as well to balance it out as the front is fractionally lower. one thing that dose how ever prevent it from being any lower is the suspension stroke, there hardly any spring in the front.

i also have no movement from the 10ish kg springs in the front. well put it this way there is a tight finger space between my tyre and guard and it doesn't touch even on rough roads. can't wait to go back to a 6kg spring

[sr_rolla]

you could modify your strut to use an insert with a similar overall length but with more exposed shaft, and getting a spring with a free length to suit that mounted further down the strut.

sorry if that didnt make a whole lot of sense, if it doesnt let me know and i'll ge to it when ive slept, ive been up for 31hrs, soooo need sleep sleepy.gif , deal with my shitty spelling rolleyes.gif

PS. i have got a few more things to add, will probably post on monday or tuesday night

[sr_rolla]

(quote old thread johnny_08)

so how much caster would be recommended for a street 86 with suspension work? or would it just differ on the car and setup and/or personal choice? ive heard pple say run max castor for drift but for grip is it just trial and error?

[sr_rolla]

(quote old thread 741)

For Grip you'd still want a bit of castor like +4 to +4.5 degrees. The effect the positive castor will give is a slight camber increase as you turn the steering further, which maintains the outer tyre's contact patch in the corner (as the outer tyre is loaded from the weight transfer). There is still alot more to it than that but thats the basics.

[sr_rolla]

(quote old thread)

my set up is

-3.5 camber
+4.5 castor
1mm toe out each side

fair low car

drives very well i love it in the hills

[sr_rolla]

on an AE86, max caster or near to it isnt that far off the mark, when i had my 86, i ran +4 degrees caster, any more than that with the springs and sway bars i had (read soft) and the car would become a little unstable at around 130, car felt like it wanted to turn at any moment, not nessecarily giving me any say in the matter rolleyes.gif

basically what I'm trying to achieve with this thread helping people to work out what and why there car is doing what its doin without just using X brand springs at the rate my mate tommo recons is the right way and the shocks and suspension settings that fred on the forums said to use.

I'm hoping that with imput from others on this site, i can help people sort out there own issues.

[sr_rolla]

(quote old thread federal)

one thing that will need to be taken into account when talling people to max out their castor is whether or not you have rose-jointed control arms....

a good stable setup would be +3.5

[sr_rolla]

(quote old thread Johnny_08)

well i don't have rose jointed anything, would it matter? hey slippery is that setup nice around corners or are u more of a kick it out sorta guy tongue.gif

[sr_rolla]

(quote old thread federal)

rose jointed control arms will change the 'actual' castor alignment

with a bushed control arm you max out the castor rod, but the control arm can't move freely into the castor, so it pulls back abit

with a rose jointed control arm, you max out the castor rod, and with the minimal resistance due to the Spherical ball in the joint, your control arms will move into the castor with near 0 resistance and have no "pull back" on them...

ofcourse this also changes if you are running rosejointed castor rods with bushed or rose jointed control arms

[sr_rolla]

when i said maxed out, i meant because i had no more gaurd clearance with 205/50/15's on mine and with a street orientated car that is setup for an improvement over standard as opposed to going all out, you wouldn't really want to cut up gaurds.

I also had stock camber at 2 inches under standard hieght (like -.3 degrees from memory) and i found mine to be good at 4 degrees castor.

[sr_rolla]

(quote federal)

i see what you mean now....

[sr_rolla]

thread updated, if anybody has any ideas on other things to discuss in the 1st post, let me know

[sr_rolla]

(quote old thread slydar)

nice post. would be sticky if i were still a mod.

re roll centers.. generally speaking, on a lowered car with rcas, do you think it is of benefit to lower the rear roll center?

i will be building a diff soon, and have noticed most production based live axle race cars, where the rules allow, the panhard bar is quite alot lower than it ends up on a lowered sprinter.

i have asked one person who has performed this mod on an ra40 and he said it made a big (positive) difference.

for this reason i was thinking of lowering the panhard bar mount on the diff down until the panhard bar was level with it anchored on the body at the stock location.

further down the track when i rose joint everything i will make it adjustable at both ends, as i will be re making the mounts to suit imperial rod ends
anyway.

but do you think this is a wise baseline to work from? (ph bar level)

apart from other evidence mentioned above, i also liken this to the use of traction brackets.. basically youre lowering the diff within its mounts like what an rca does at the front, so i don't see how i could go wrong.. unless I'm missing something.

[sr_rolla]

(quote old thread anthony)

Yeah great information. My only gripe would be to avoid going out of your way to widen the drift/grip divide. The information is equally useful to both disciplines so I'd hate to see someone interested in drift to disregard it

[sr_rolla]

1st post updated just for you SLYDAR rolleyes.gif

seriously tho, with regards to the panard bar, unless you make all the 4 link bars equal length and parellel with each other and the ground, the best thing to do would be to make a panard bar thats hieght adjustable at the body and diff end and just stuff around with it till your happy. There are ways of measuring where the rear roll center will end up whilst using un-parellel 4 link bars but it still comes down to how it feels to you. With the traction brackets, i assume that the idea is to lower the diff end of the lower rear links? I havent seen them but if thats the case they can work well. If they lower the links to the point that they are paralell with the ground it can only be a good thing, for best results (if thats what these traction brackets do) i would also run equal length, paralell top bars and correct the pinion angle while i was there, as i assume the nose of the diff points up at the floor atm if your car is severly lowered.

Then with a height adjustable panard bar, the rear roll center will be the center of the bar so easy to see, let alone work out.

Anthony: Whilst i can see what your saying and i appreciate that drifters and grip guys can share parts and information, they are in effect chasing different goals. A grip driver wants to make the best possible use of the grip he has and will try as hard as possible to avoid excess slip and a drifter wants a car that can hold a high speed, stable, controllable slide and have the car controlable after grip has been mostly lost. Anything that involves car control can be shared between the two but to many other things are at odds. I'm all for uniting the 2 factions of drift and grip but what i think we really need, as loc33e said, is a thread like this but for drift, and unfortunately theres not enough good tested theory on drift atm to do that.

The main reason I put the title up the way i did was to hopefully avoid people putting up drift setups and confusing the thread but as u said, some of the principles in here can be used for drift...

Well that and i know stuff all about drifting

[sr_rolla]

(quote old thread anthony)

Just call it car setups in general, Make it a universal document. ie. pinion angle... if you do A you'll get B, if you do C you'll get D and let people take from that what they want.

If some beginners are chasing slip from the start, eventually they will want grip back, and if they understand how the two relate from the very beginning they will be able to get a lot more out of their car.

[sr_rolla]

(quote old thread gunner)

thats really helpful dude, as i know sweet fa about suspension set up, though i have a question, bit noobish but anyway.

I have an s14 rear cradle sittin around, anyway from pickin it up and movin it, its lighter than my t series, I know that, to have all the work done to fit irs to the rear of an 86, kinda outweighs the positives, and i know you can get a live axle car to handle/grip just as well as an irs car, but my question is, would it be an improvement, due to the removal of so much unsprung weight, I've spokin to my fab bloke who is doin my cage, and hethinks it wouldn't be much more work, considering, that we wouldn't be doing equal 4 links and those associated pieces. plus i end up with my brake conversion for the rear too.

Anyway back to the question i would like answered. Would removing the unsprung wieght of a live axle, and replacing it by the sprung weight of a rear irs cradle be an improvement, and would it help to offset the wieght of a bigger engine?

Cheers
Rhys

[sr_rolla]

(quote old thread kaibeecee)

i think you're not factoring in the diff-centre weight itself, shafts, stub-axles and the other ancilliaries involved, it turns out to weigh alot more than a live axle setup

[sr_rolla]

(quote old thread highlife)

IRS rear end has much more adjustability than a live axle setup - and also much less unsprung weight - so yeah there will be advantages, wether or not its worth the hassle/$$ is up to you.

[sr_rolla]

a guy that used to be on here, improvedae86, did just what your talking about. The main thing to factor in is to make a heap of measurements, if its to wide, the car will understeer and if u end up getting toe change on suspension compression then it will be horrible to drive and then you have 2 factor in the camber changes aswell. What r u using the car for? do u want it to turn or do you want a drag car? Whilst having less unsprung weight is good, having correct geometry is better. I personally would run an equal length 4 link setup with a live diff and maybe a watts linkage setup.

In laymans terms, i'd rather have a rear end setup that works properly and is a little heavy than a trick light weight IRS setup that doesnt do what its told

[sr_rolla]

(quote old thread gunner)

Thanks guys, sr rolla the car will be used primarily for grip work, what do you mean if it is too wide it will want to understeer, as in its width in relation to a narrow front end, the front is gettin a fair wack of extra track.

I understand that if it isn't done correctly it will be worse that a standard car, I've learnt just how bad things can go on a drag car when the geometry changes under compression, I could only imagine what would happen mid corner and for somethin to go out out of wack.

At the moment it is just an idea, as the equal 4 link, and watts link are the way i was intending to go, though since i have access to a complete rear subframe, and since the rear floor is gettin chopped up, i think it would be good to weigh up the options available involving rear irs.

thanks guys great help

Cheers
Rhys

[sr_rolla]

(quote old thread gunner)

Ok suspension gods I have another question, I have complete S14 struts, control arms, etc (I have recently finished a big upgrade on an s14 for InTheRed tuning)
now i haven't done any real measurement as yet, but i would like to know, whats going to be the limiting factor in fitting these, the only real issue i can see is that i will have to dick around with strut tower mounts (bring them further out, it is roughly 100mm either side) or is it more complex than that, sorry to be a noob, but I'm only learnin suspension i know how to go fast, just not how to turn lol.

[sr_rolla]

personally, i would stick with the toyota setup and improve on it, basically the only problems with the front end in a ae/ke is the castor rod arangement and the balljoint location. If u could move the balljoint closer to the disc (ie outward) u will improve the scrub radius properties and it will be nicer to drive with fatter, dished wheels. I don't like the S13/14 setup on a KE/AE, the balljoint angles are wrong, all the mounts are in the wrong place, its just a pain in the arse (altho plenty of people here will argue my point no doubt). There is also a whole heap of other variables that come into it that make things difficult. Ackeman effects, scrub radius changes, angles changes between the LCA and tie rod, the rate at which these changes happen as the suspension moves, etc.

If u really want to run silvia stuff, the only way to do it properly is to measure across the strut tops and from balljoint to balljoint at the bottom when everything is mounted in a stock silvia, then measure the balljoint-balljoint when the silvia lower arms are in the ke/ae, then take that difference and take/add that amount to the silvia strut top measurment and go from there. Also bare in mind that with this setup, if u want it to work right u will need to lose the deep dish front wheels.

[sr_rolla]

(quote old thread gunner)

Well the idea, was to mod the strut towers, and what ever else, to bring the angles closer to that of an s14, I know that if any of the angles, or distances are balls up, it won't work. And i don't like the idea of bolting in s13 stuff, it can't be better than quality stuff built for an 86, and I'm not after camber, just track, and the ease of findin big brakes

[sr_rolla]

Why do you want to increase track? AE86's have a near on perfect width to length ratio to start with. If you are deadset on increasing track, I would probably use wheel offsets to achieve what your after and use more of a standard derived setup on the suspension. With the brakes i wold just be chasing a strut with a larger diameter stub axle so that you can run larger wheels (width and dia.) without flex. For brakes, theres plenty available, theres the hilux pug/setup, the mini/rx7 setup through AJPS and it wouldn't be overly difficult to get any caliper disc setup you want, just get a caliper adapter machined up and work off a disc that will bolt to a standard hub or machine your own hubs up. If you could fit a big enough wheel you could even adapt a porsche setup to a sprinter/corona/celica strut.

Also, the pug/hilux setup is awesome, i have it and according to the engineer who tested it, it has similar stopping power to a porsche and NEVER gets fade. I only ever got fade once and it was coming down from 180kp/h to 60kp/h and it got a tad spongy, i had full brake by the next corner tho. I don't have braided line, i have standard hilux pads, standard shitty rotors and celica drum rears so i can improve on that aswell.

[sr_rolla]

(quote old thread hatzo)

First off a bit of history of the Ackerman angle concept..
the concept was devised all the way back in the 1800's
to keep carriage wheels from upsetting gravel driveways,

In normal road situations ,
it is wise to keep the pro Ackerman (dynamic toe out on turning) geometry ,
due to the slow speed* (Low lateral (across car) loads) nature of driving on public roads.
*depends on how much you want your license

But as the lateral loads are increased with speed,
there will be more drag placed on the inside front tyre than necessary
so as the car is turning thru the radius of the turn.
the car will understeer , as well as causing overheating of the tyre.

The solution is to reduce the pro-Ackerman effect,
and bring the steering geometry towards or to a parallel type arrangement.

Thats about as simply as i can put it (its taken many rewrites + 1hour) ,

One last bit .
Tyres are the single most important factor ,
on how a car performs.

[sr_rolla]

agreed in part, ackerman is a little more complicated than that, it depends on the car individually. Different sidewall sizes front to rear, different offsets, tyre slip angles etc all play a part. Ackerman is hard to measure and hard to change without effecting other geometry, to be honest it is beyond most of the people on here to diagnose and change, we don't have access to the tools nessecary. Hence why i explained it but said not to change it.

I do agree tho, tyres are the most important part of the suspension.

[sr_rolla]

(quote old thread gunner)

lol, I need to do some research I think, as none of that makes much sense, I understand what's being said just not in depth if you know what i mean.
Sorry for the noobness, I make things go fast, not turn corners so its all foreign to me, though its probably good for anyone reading it as we're gettin alot of the tricky stuff out there. Anyway back more questions lol.

I understand tyres, and how important they are, and the effects in terms of sidewall hieght and flex, I've done enough street racing to understand that too little sidewall isn't good, and too much isn't good. Though it wouldn't hurt for someone to explain the good and bad affects.

So if i was to run the standard style of 86 suspension, and i wanted to run a 16" wheel, what do i need to change, and also if i was to gain the track i want through offset, what needs to be changed for that.

The reasoning behind wanting the track is, I do plan on makin a fair bit of power, not cause i need it, just cause thats what i do, and i can't help myself lol. And I like the idea of square car (in terms of track and wheel base) I know the sprinter is good, and they are near perfect as you said, but near perfect isn't perfect.

Thanks heps guys
Rhys

[sr_rolla]

(quote old thread konakid)

Thankyou, thankyou, thankyou!

I am also a firm believer in obtaining track mainly from the combination of wheel offset and width instead of uber long control arms or different struts. Standard geometry is good from factory which is what a lot of people don't understand. Its much better to improve on what you have been given with from the factory through the 86 struts than trying to re-engineer a different setup from another car through trial and error. Take one look at every japanese sprinter that comes here or is over there, not one will use non standard struts. All have either stock vented brakes, FC upgrade or something off the shelf.

sr rolla: Any idea on the weight of the pug/hilux setup compared to stock JDM Vented? I saw on here that the FC setup is only 1kg heavier than JDM, interested to see how it compares.

[sr_rolla]

(quote old thread konakid)

To gain track through offset, all you really need to worry about is how much guard clearance you have on the outer edge of the wheel. Naturally this means either bolt on flares or working the stock metal guards will be required to get some big increases in track. In an 8J wheel, -4 is about the lowest offset that will fit in stock guards.

The problem with making large amounts of grunt (200rwkw+) in a car like the 86 is that its size (more so the parts) work against it. See, 15" is pretty much the perfect size wheel for fitting the guards and when combined with a quality 195/50 has enough grip for all power levels in N/A 4age form and 4agz/te up to about 200rwkw. Keeping a wheel this size also keeps unsprung weight down, tyre price down, rotational weight down etc, it just works.

When you start making big numbers (I'm talking 250rwkw) you run into a few problems. First of all is brakes, which is cured by the FC setup or similar fix. Secondly, to use this much grunt your going to need grip, usually more than what a 205/50/15 can deliver so you'll be looking at 16's with 215/45's or the like. I'm guessing you already know that you'll need a big diff to cope with this grunt, and you would definitely want some sort of brake upgrade on the rear. Then you'll need to find an LSD for this diff. Custom tailshaft will be needed obviously and depending on the motor the gearbox may even need to be swapped out for a stronger one. Then you need to make sure the weight balance is good so mounting the motor as far back as possible depending on what you use.

So there are numerous things that need to be done and a lot of effort to make it all work but it can be done, Medwins sprinter was on the right track as far as big power sprinters go but i don't know how it would have performed in real life.

So its a lot of work

[sr_rolla]

(quote old thread gunner)

The problem with making large amounts of grunt (200rwkw+) in a car like the 86 is that its size (more so the parts) work against it. See, 15" is pretty much the perfect size wheel for fitting the guards and when combined with a quality 195/50 has enough grip for all power levels in N/A 4age form and 4agz/te up to about 200rwkw. Keeping a wheel this size also keeps unsprung weight down, tyre price down, rotational weight down etc, it just works.

When you start making big numbers (I'm talking 250rwkw) you run into a few problems. To use this much grunt your going to need grip, usually more than what a 205/50/15 can deliver so you'll be looking at 16's with 215/45's or the like.

Seriously no offence Kona Kid, but thats all thats really relevant in this thread. It is a suspension thread after all, though i agree with what you have said.
And if you could explain the weight issues and the effects it has on the suspension a bit more in depth, that may be good for people.

I would of thought that if you, increase track through wheel offset and width, it would still upset angles. True or false? and why?

[sr_rolla]

(quote old thread konakid)

Sorry, went a bit OT, all good.

Its best to use a combination of LCA length and width and offset to achieve a larger track as its all about balance.

Using a 10mm longer control arm for instance with a 8J -10 wheel would be better than a stock arm with 8J -20 for example to get the desired track increase. Keeps the scrub radius in check, Doesn't put as much weight further outboard of the strut and on the stub axle and limits tram lining. The reason i say offset/width, is because using the two you can get the inside of the wheel as close to the strut as is possible to keep the scrub radius low while the outer edge can be much further out than stock to increase track.

People who use Sigma LCA's, get an extra 30mm from the longer arms then want to run a neg offset wheel, massively increasing the scrub radius. Not to mention that the super long LCA causes other handling issues such as tram lining where the wheels want to follow channels in the road and the car pulls towards ditches and holes when the wheels hit them. Also most often don't increase the rear track to keep it all square and so high speed oversteer scary moments do occur.

Hope that helps a bit.

[sr_rolla]

(quote old thread gunner)

Thats perfect dude, I knew it would effect somethin was just unsure of what.

I'm havin a look at a few options tomorrow, will post what i discover.

Cheers
Rhys

[sr_rolla]

(quote old thread mattyn)

hey i have a question in relation to track and mismatched track front to rear.

i have in my possesion a set of rims i was running on my GTiR. the rims are mismatched.
dimensions as follows,
2x 15*6.5JJ +38
2x 15*6.5JJ +45

all wheels are running a matching set of bridgestone potenza G3's dimiensions: 205*55*15

i suppose firstly will they fit under JDM trueno sprinter (still in compliance so can't check myself), and what will be the effect of the mismatched track in a rwd, balanced setting (vs the front heavy AWD GTiR)

cheers for your advice id like to run these tyres and wonder if these wheels will suit.


matt

[sr_rolla]

(quote old thread federal)

they wont fit....wrong stud pattern...

[sr_rolla]

gunbz-r don't assume that a square car is the best way to go, the best ratio is 1.7:1 as in 1 being the track width and 1.7 being the length so for example if the car is 2m wide for example the wheelbase has to be 3.7m long for the best handling. A ae86 has this ratio standard, if you try and make the car more square it will turn in really well and be very stable at slow speeds but be extremely nervous and difficult to control at speed. I would work off a 205/50/15 semi slick to give the the grip you need on a 5x8" rim.

K onakid: The pug setup is heavier, but, it depends what your after, if you don't have the hp to warrant it then the rx7 setup may be better, however, if you are running bigger wheel loads (more rubber, more brakes etc) then the bigger stub axle of the corona strut makes up for the extra weight and the hilux caliper is extremely rigid and cheap. So i spose its horses for courses really. If i was running a 4A, smaller wheels and didnt need the braking power then i wouldn't run the pug/hilux setup.

mattyn: run 7mm spacers on the +45 set as a start to bring the front/rear offsets in line. Then use different spacers to get the wheels sitting right in relation to the strut/gaurd. But thats if the stud pattern is right. Or buy the right wheels to suit it

[sr_rolla]

(quote old thread gunner)

I've never heard that about that ratio, makes sense, thanks dude.

[sr_rolla]

(quote old thread Mcdrift)

can anyone explain how to adjust camber tops ei where to put the 4 bolts for what camber ? or anyone got a link to a guide?

[sr_rolla]

(quote old thread federal)

there is no "guide", as too many other things factor into the results....

if you don't know what your doing, take it to a wheel aligner....only way to get it right.....

[sr_rolla]

agreed with F EDERAL, take it to a wheel aligner, to make it easer in the future, get the wheel aligner to get a few settings (2, 2.5 degrees neg etc) and mark them out on the strut tops> It makes it easier to change your settings later on

[sr_rolla]

(quote old thread stylz)

One quick question guys. How do i get suspesion droop?
Atm I'm running tokico short stroke shocks on all 4 corners with 10kg front and 8kg rear springs, i don't know the hieght of the springs but the cas sits slightly above legal height.
I plan on going 8/6 or 7/5 rates as i like doin hills runs and dori.

So what do i need to do to get 2 inches of droop? Do i need longer springs or do i need to get rid of my short stroke shocks?
The write up explains what it is but not how to achieve it :/

[sr_rolla]

(quote kona kid)

Droop is easy to measure, simply measure the distance from your guard edge to the ground, then jack the car up by the chassis until the tyre 'just' starts to lift up. Now measure the disance between the guard line and the ground. the difference in these measurements is the amount of droop you have.

Say the shocks are 2 inches shorter than stock at full stroke for example, you car will need to be at least 2 inches lower than standard to have as much droop relative to what is has from the factory.

Hope that helps!

[sr_rolla]

a more acurate way to do it is find a place with a 4 post hoist, the ones that lift the car by the wheels, and measure the shock/struts at static hieght. then lift the car by the chassis and measure the extended langths. The difference will be your droop measurment. In a car that is driven on shitty roads i would aim for closer 2 3 inches if its driven on good roads aim closer 2 2 inches

[sr_rolla]

(quote old thread stylz)

yeah, done that and found i have shit all droop. how do i go about setting it up to have more droop?
i have tokico short strokes in atm and I'm not sure what i have to do :/

[sr_rolla]

(quote old thread hatzo)

This is about the roll steer/ rear steer / what other name people call it

If you watch enough top level motorsport (F1 , V8 Super cars) ,
you will see they all run that type of rear suspension geometry.

It improves all facets of cornering

Where people get unstuck ,
is when they use the:
"People with Nissans remove HICAS , so that means I need to lock up my rear end"

The real reason , is that it is a Hydro/Electronic System, and It isn't predictable.

One more thing , inexperienced drivers , don't have the skills and experience ,
to be able to diagnose there handling issues.

99% of a cars speed is the Driver

[sr_rolla]

(quote old thread konakid)

If you ahve short stroke shocks and you have only a tiny amount of droop, it means your car isnt low enough for your shocks.

[sr_rolla]

(quote old thread gilly)

changing to the softer 7/5 spring set up should give you more droop as the car will sit lower and the shocks will be in a better range of stroke, if you have minimal droop the shock's stroke is significantly reduced as the shock is being held nearly on full extension.

optimal stroke is a dark art it seems, i always thought mid stroke was best and its still what i aim for. different motor sports though vary in whats the best range. thats a whole new can of worms.

[sr_rolla]

(quote old thread slydar)

rebuild your coil overs with a spacer under the insert.

[sr_rolla]

Pretty much what slydar said, you need to rebuild the front coilovers with a spacer under the strut insert to in effect raise the insert in the strut and allow more droop. As previously mentioned, i'd aim for about 2-3 inches of droop from static hieght to allow for this countries fine roads (not). For the rear, u need longer shocks, plain and simple. measure what you need and head to a parts place (not supercheap) and find a monroe or gabriel parts book, look thru it till you find something with the apropriate length (comodore, celica, seirra shocks are a good start)

I can put up a few basic pics to explain all this for people if the demand is there, i'll have to draw it up though.

GILLY: what you said about aiming for the middle of the stroke is not a bad idea, if you have shocks with a very short stroke.
The koni dampers I'm going to be ordering soon have a stroke of 153mm front and 143mm rear, so in this case your theory would be pretty good.
However they make dampers that due to there design have anywhere up to 300mm of stroke, now in that case (depending on application) i would be running whatever droop is apropriate and leaving the rest as compression.

HATZO: agreed on the drive car comment but i have no idea what you are talking about with the whole rest of your post, roll steer is bad, plain and simple, as the car rolls into a turn roll steer causes the car to get toe changes (in effect) that cause the car to under/oversteer. The only way that this may be used is if a chassis is over powered for a particular circuit or to solve another problem. For example, say an light sedan (corolla, escort etc) has like, 400kw's, because of the shitty aero traits that this vehicle has it will be a handfull at high speeds, you may want to dial in a little roll understeer to make the car more stable at speed. I can't think of any other reason to have rear roll steer on purpose in a racing sense. Genrally, the problems that roll steer fixes are caused by something completly different that can't be changed (due to class rules for example, ie aero inefficiences).

Unless you are talking about something to do with adjustable rear rollcenters?

[sr_rolla]

(simon ae86)

SR_Rolla: whats your views/opinion on shortening the LCA, and redrilling the mounting point for the LCA on the crossmember further out? Hypothetically if u redrilled the hole further out by 40mm, then shortened the LCA by the corrosponding amount what kind of effects, both negitive and positive would it have.

not looking for a flame war or "why the fuk would u do that" but just curious.

[sr_rolla]

In theory, it could work, if i was to be trying this mod though i would be concerned about bump steer problems to do with shortening the LCA. I'd move the inner mount outboard, get a spare set of LCA's with new bushes and ball joints that are stock length and then get some shortened ones, also with new bushes and balljoints. Then i would get hold of some adjustable strut tops and a spirit level. 1st i'd get a wheel alignment, then do a few runs of either a road that you know really well or a race track, with stock LCA's at the standard inner mounting point. Bring a mate and take some notes about corner speed, rpm, how the car feels etc. After that do your mods to the inner mounting point but put the stock LCA's in, then get it wheel aligned to all the previous neg/caster/toe settings and go for another run, take notes etc, then put the shortened LCA's in, wheel alignment to previous settings/test again.

This is really the only way to properly see if it has a reasonable effect or not. My guess is it wont have a real positive effect but thats just my personal opinion. Go nuts and try it if u feel it may work.

[sr_rolla]

In theory, it could work, if i was to be trying this mod though i would be concerned about bump steer problems to do with shortening the LCA. I'd move the inner mount outboard, get a spare set of LCA's with new bushes and ball joints that are stock length and then get some shortened ones, also with new bushes and balljoints. Then i would get hold of some adjustable strut tops and a spirit level. 1st i'd get a wheel alignment, then do a few runs of either a road that you know really well or a race track, with stock LCA's at the standard inner mounting point. Bring a mate and take some notes about corner speed, rpm, how the car feels etc. After that do your mods to the inner mounting point but put the stock LCA's in, then get it wheel aligned to all the previous neg/caster/toe settings and go for another run, take notes etc, then put the shortened LCA's in, wheel alignment to previous settings/test again.

This is really the only way to properly see if it has a reasonable effect or not. My guess is it wont have a real positive effect but thats just my personal opinion. Go nuts and try it if u feel it may work.

[sr_rolla]

(quote old thread simon ae86)

Thanks for that, ok no more hypoteticals here, I'm running the S13/14 crossmember in my KE, and have stock KE LCA's on there, obviously the LCA mounts on the LCA is much much further out compared to stock (and i have the camber to show for it) Now i am trying to make it all work and work well.. just to get the car going i rigged up the stock KE susp, stock struts and springs and all... whilist it works, its a little on the bump steery and vauge side.

So I'm in the process of running the nissan stuff in terms of brakes, hub, strut etc, makes sence since the rack and crossmember is all nissan, so should work reasonably well...

my biggest prob is, i can't run the standard length S13 LCA, since it is miles too long and combined with the LCA mounts on the Xmember which are further out already in relation to the K Xmember, the track os going to be huge.

So.. was thinking of still running all the Nissan stuff, with S13 control arms, but shortened, I feel that bump steer should be eliminated compared to the K series susp due to the steering arm linkage point being matched to the rack location.

Cheers!

[sr_rolla]

bump steer may be eliminated but unfortunately everthing else ends up stuffed. basically, the only way to run nissan stuff properly is to A) run stupid wide track and + offset wheels, or shorten the LCA's like u said and move the strut tops in a similar amount.

Sorry to break it to u but it just doesnt work well, the ackerman angles are stuffed, the front 2 rear track is stuffed, and even if u do alter the rear track to suit the front the car ends up over-square and it wont handle anyway.

Theres a reason beau yates and co. don't tend 2 do this mod, and if it was an awesome mod they would use it in N2.

Sorry dude if that destroys your ideas but thats what i have found from what ive researched

What may fix your problems is to used ae86/ke70 style struts and LCA's and redrill the crossmember 2 bring it back 2 stock position, then adjust the bump steer out of it. It is posible and way easier than making the nissan stuff work

[sr_rolla]

(quote old thread simon ae86)

yeah but redrilling the LCA's further IN (back to where stock KE/AE mounts would be) is an ideal solution, however then you regain the bumpsteer due to the rack end (tie rod) and LCA pivot points being totally different.

I used to run s13 susp in my drift ae86 back when i was drifting with beau before anyone knew who he was.. and while it was slapped together, it worked reasonably well., however i was using a AE86 crossmember with cut and shut s13 LCA's and overly stiff coilovers.

this time round, i'm looking at doing things a little differently.... I'm with you tho, on paper it seems it may not work, but i'll give it a go and see what happens, if worse comes to worse i'll redo it all

[sr_rolla]

(quote old thread ke70dave)

this is interesting to read....

i have S13 front end in my car (s13 stocko LCA's),8kg springs, and am running 15x6.5 + 23? wheels, with 195/50/R15 tyres and with completely untouched ke70 guards, -2 degrees camber (set with camber tops), and castor set to zero. The tyres foul on the guards but only when you hit really really big bumps (so essentially clear guards, just need to give them a bit of a roll). and car is around 130-140mm off ground at chassis rails.

anyway....

i do not experience any bump steer at all with this setup (my definition of bump steer as explained in the following)

the way i have tested this is as so, i drive down the bumpiest road i can find (not hard in backstreets of wynnum), and get the car going straight, and let the wheel go between my hands, so let it do what it wants. i do not find that the steering wheel moves at all in relation to when the wheels meet the bumps.

i have looked at my LCA and steering arm, and they appear to be very close to parallel at the static position as shown in the pic i just took (not the best, but its too cold to stay for too long out there..)

121


now unfortunately i have not had a chance to experience "bump steer" in the sense of lowering my car with stocko stuff withouth adding RCA's....as i went straight from stocko height to this setup.

i also have not had the opportunity to drive "proper" ae86 coilover/lowered spring with RCA setup to compare with, so i guess I'm kinda in the dark a bit when it comes to that...

so basically I'm wondering if any of you goo-roo's of suspension can either point me in the direction on how to find this apparnetly bump steer that is present with s13 gear, or address me in any of my possible wrong thinking?



ps: one thing i would like to try, is to take the springs out of my coilovers and put it all back, jack up the car, and move the front suspension through its complete suspension travel, and see if i can see any of this bump steer...but taking springs off is to much hard work...

[sr_rolla]

I am so glad you put that picture up in here biggrin.gif

Basically, bump steer, is not steering caused by bumps, that is a scrub radius problem (refer to 1st post).

Bump steer (refer to 1st post) is when the toe angles change under suspension compression/extension. This is commonly caused by different lengths of the tierod end to rack end vs ball joint to inner bush, or the LCA and tie rod being in different points of there arc of movement

Now on to said pic, and I'm gonna be brutally honest here.

Firstly, the tie rod end is all cocked over at a bad angle, that has the posibility of pulling out the ball of the tierod.

secondly, the steering can, under the right circumstances, invert, as in the tie rod could pass across the LCA and end up in front of it.

Third, the arms arent parallel, well, the arms are but there pivot points arent. u need 2 draw a line between the rack end and the tierod end and thru the center of the ball joint (where it pivots) and the center of the LCA inner bush. If you do that you see that the arms arent level at all.

fourth, u need 2 measure the length from the rack end to the tie rod end and the measurement from the balljoint pivot point and inner bush pivot, if these are way different then you will get bump steer.

My basic point is that while i think this setup could be made to work, it is much easier to make the standard design work. All u really need to do for a basic setup that will do what 90% of people here want, drift or grip drivers included, is get some nice bushes, some corona front arms, some RCA's and a rosejointed castor arm arangement. The major issue in the front of ae/ke's is that the castor rod bush is a shitty design and moves around alot, giving a vague feeling, if you rosejoint it or change the design to something similar to a silvia castor arangement then it will handle very predictably and wont have any issues with geometry.

[sr_rolla]

(quote old thread simon ae86)

this is the reason in my choice of using the nissan crossmember and rack, all pivot points should be the way that nissan designed them, in theory anyway.

KE70dave: interesting to see you used stock length arms, you didnt find them too long and cause massive camber? Or did you slot the top bolt hole on the coilover strut to reduce camber?

[sr_rolla]

(quote old thread ke70dave)

nah seems to be ok, but I'm using pretty "crap" offset wheels (in ke70 and ae86 terms) as stated they are 15x6.5 +23 with 195/50's

this is with the camber top on full negative (-3 deg), and i havent modded the top holes at all, standard placement.

i don't have a pic of it now (with -2 degrees) but its pretty much flush with guard (those stocko ke70 guards in the picture are essentially untouched)

i would like to get shorter ones, but better things to spend money on/worry about for the moment

[sr_rolla]

(quote old thread ke70dave)

ok i have results

at the crossmember end it was found that where the LCA bolt and where the steering arm joints the steering rack (right at the ball joint) is essentially in EXACTLY aligned.

i did this by putting a screwdriver in line with the LCA bolt and lined it up with the ball joint in the rack end, and the screwdriver was essentially parallel.

also i figured this end wasnt as important because its the same setup that is used with ae86 stuff anyway (Same LCA bolt position, and same steering rack position)

now onto the other end.....

here is a diagram i drew up in solid edge, its 1:1 scale so its all exact. also note i took these measurements with weight on the front wheel, i put some bricks under the control arm and let down the jack to get as close as i could to static position.

also the measurements of the ball joint were taken at the pivot point of the ball joint (or close too..since you can't actually see it)

122

now as can be seen, the steering arm is 30mm shorter than the LCA, and the steering arm sits up 10mm higher than the LCA at the brake disc end.

now i have nothing to compare to, but how bad is this in terms of "bump steer"??

just thought id post my results anyway...

[sr_rolla]

(quote old thread simon ae86)

the more crossed up those two arms get the more pronounced the bump steer effect, when i fitted my susp up, i had a horrible angle on the tie rod, since the S14 rack is a lot lower then KE, so the start of the tie rod was a lot lower then the ball joint end where it bolts to the steering arm, I temporarily fixed mine by using bump steer adjusters on the toe arm, dropping the arm about 50-60mm lower from the steering arm.

[sr_rolla]

(quote old thread ke70dave)

ok i have my own answer

after doin a bit of thinking, and mucking around in this program, i have come up with the following results

considering 2 scenarios

the first scenario is with a suspension compression of 50mm (a fair way with 8kg springs, but certainly obtainable) it sias 49.5mm but close enough

here is the geometry:

123

now as can be seen, as the control arm is moved up 50mm, the pivot point at the ball joint moves 3.52mm, where as the steering arm moves in 4.64mm, resulting in a toe out
change of 1.12mm (considering only one front wheel, assuming the other wheel does not get effected by this suspension compression)

now the next scenario, is a worst case scenario, where the suspension is compressed 100mm (this would be a pretty psycho bump, and woudl result in worse things than bump steer...namely bottoming out...but neverthe less...)

here is the geometry for a 100mm compression:

124


as can be seen from this diagram, for a suspension compression of 100mm, the control arm moves towards chassis by 14.59mm, where as the steering arm moves in by an amount of 16.08mm. resulting in a toe change (toe out) of 1.49mm with 100mm of suspension travel

now obviosly this is a definite answer to the fact that there IS bump steer in s13 in ke70 suspension (bugger eh:P), so my question is...how bad is this? compared to what is acheivable with ae86 stuff? anyone keen to get out the measuring tape on their cars?

comments are most welcome

[sr_rolla]

(quote old thread simon ae86)

pretty decent findings mate,

in your first senario... 1.1mm toe change is SFA really... so theres your answer right there wink.gif there IS bump steer, but not heaps

[sr_rolla]

Firstly, top work KE70Dave, those graphs look very similar to the professional bump steer graphs, u get a gold star tongue.gif

I think that 1.1mm is a reasonable amount of bump, because if the whole front end is compressed (under brakes maybe) thats a 2.2mm toe out.
the easiest way to fix it is to do what Simon-AE86 touched on and space out the tierod end. To do this i would piss the tie rod off and use a piece of threaded tube and a rose joint (AJPS sell these) and then run a bolt/rod through the hole that tie rod currently bolts to and space the rose joint out till you have no bump steer. Also, a really acurate way to test for bump steer is to make a bump steer gauge.

to use said bump gauge, take the springs out of the car and raise and lower the car thru its range of travell, this will tell you how much bump you actually have.

also, KE70Dave, those front knuckles, are they made of aluminium of steel?

If steel, i'd suggest getting the tierod mounts heated and twisted around to sit the correct way in relation to the tierod or if aluminium, machining the the hole out bigger and at the right angle, then weld in an insert that gives you the strength back. It would be a bit of stuffing around but its safer in the long run.

[sr_rolla]

(quote old thread ke70dave)

that's an interesting contraption....still can't figure out how it works though...but i can see what its trying to do i think..

the thing is...now that i've become aware of this apparent bump steer, damnit i can't make it steer on any bumps!!!

i've gone over speed bumps with only one wheel, and tried to get it to bump steer, ive gone up slanty gutters pretty quick and can't get it to do anything!!!!

so is it really that much of a problem? (the bump steer that is....the tie rod mount i can see where your coming from...but its been like that for 1.5yrs....soo.....)

the next thing i'm going to do, is put a wire-tie around my shock absorber piston, and see how far my suspension actually travels under normal driving, and then try it going over bumps.

the other thing is....the alternative is ae86 stuff....surely there is a little bit of this bump steer in that as well? suspension setup is all about trade offs they say....and no system is perfect.... i'm going to try and track down someone with ae86 stuff and let me at it with a tape measure, see what i can come up with.

[Konakid]

1st post updated just for you SLYDAR rolleyes.gif

seriously tho, with regards to the panard bar, unless you make all the 4 link bars equal length and parellel with each other and the ground, the best thing to do would be to make a panard bar thats hieght adjustable at the body and diff end and just stuff around with it till your happy. There are ways of measuring where the rear roll center will end up whilst using un-parellel 4 link bars but it still comes down to how it feels to you. With the traction brackets, i assume that the idea is to lower the diff end of the lower rear links? I havent seen them but if thats the case they can work well. If they lower the links to the point that they are paralell with the ground it can only be a good thing, for best results (if thats what these traction brackets do) i would also run equal length, paralell top bars and correct the pinion angle while i was there, as i assume the nose of the diff points up at the floor atm if your car is severly lowered.

Then with a height adjustable panard bar, the rear roll center will be the center of the bar so easy to see, let alone work out.


Good work on copying the old thread over!!

I am very keen to get my hands on a cusco rear RCA that does the same thing you described, lowering the diff end panhard rod mount so its basically flat, but im doubting it would make much of a noticeable difference.

Any one tried it?

[sr_rolla]

Ke70dave: You wont feel it on bumps, the best place to actually feel it is under heavy braking and acceleration, as the front of the car rises and falls the toe will change either in or out makeing the car unstable (see: lowered r32 and later skyline and 300zx's as a good example of shocking bumpsteer).

The way that interesting contraption works is as the car is raised/lowered thru its travel the front bolt will come away from the wheel during a toe in situation and the oppsite will happen (rear bolt comes away) in a toe out situation. when this happens u will know where in the travel the bump steer is occurring and by how much (the amount of gap between the bolt and the wheel) so u can fix it and test again.

With the tie rod, i had another idea, get some spare tierods that are a little longer and heat/bend them so the tierod end is in the correct orientation, that should fix the prolem I'm concerned about.

Also, I thought i'd put up a few piccies, The first few are of the car with the white underside belong to 1 of the TRD prepared AE86's that raced at bathurst in the 80's (the pics belong to someone on here, i can't remember who but if theres a problem using them let me know and i'll take them down). Alot can be learned fron studying these pics, especially the front end. If you look at the way the castor rod has been attached to the tubular LCA, it can pivot, this is because when the front end is rosejointed there is no longer any give from the bushes. With no give, as the suspension moves up and down or when caster is adjusted, the angle between the the LCA and the castor rod needs to change, otherwise it will try and bend or pre-maturely break rosejoints. Other than this, if u look carefully, the outer spherical bearing (where the ball joint was) has been moved closer to the disk, with this they are trying to address the scrub radius problems that this setup has. The bar with holes in it (red on the rear end photos black on the front) is the sway bar arms. This is kind of like a progression from the older more standard style sway bars to the blade adjustable bars of today. The rear end pics are just a really good example of how to do a rear end properly and the blue setup is a formula (i think) setup that AJPS was selling second hand, this is a very similar setup to the TRD setup but out of the car obviously.
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[sr_rolla]

(quote old thread ru-iki)

Love the pics of the hot race car suspension, but the rusty old stilsens on the ground for adjustments.



My mechanic only worries about bump steer once the lower control arm on my ke gets above horizontal. At this point, its beyond the range of motion its designed to exist in and bump steer becomes evident.

Every steering system must have some geometric variation as the suspension is compressed and rebounded (as evidenced by the pivots discussed above in the trd stuff). Perhaps the trick is to get it pivoting from just below to just above the horizontal position, being that the tie rod end and lca are parallel in the system. Lets call this variation x, which is in this case + or - above the horizontal. Meaning the total variation in geometry is only half what it could be.

If you went a bit lower and the lca was horizontal to begin with, upon the same compression as above, it would displace a distance of +2x.

Make any sense? If you know what Im on about Dave, id love to see a diagram. Feel free to pick me to pieces I'm thinking out loud here..

...top thread, finally some nitty gritty..

[sr_rolla]

(quote old thread ru-iki)

The other thing that hasn't been touched on yet, is what happens when the suspension compresses while you are tuning, displacing the steering sideways and altering the angle between the lca and tie rod. This must have a more drastic effect than anything in a straight line. I've always worried about the bump steer I feel when turning, not really in a straight line.

[sr_rolla]

u wont feel true bump during turning as toe changes whilst turning due to ackerman angle anyway, what u feel is scrub radius problems. as u hit a bump (in a rolla/sprinter at least) the wheel is forced backwards from its pivot point so it fells like its trying to steer. Alot of older cars have this problem as the balljoint is to far inboard from the tyre contact patch. This is y most new cars run a system where the balljoint is basically in the wheel.

In a rolla u have 2 basically deal with it, im gonna be workin on some ways to improve it a little but unless you completly redesign the front end theres not alot u can do

u have 2 lose the deep dish wheels aswell

And back to the 1st point, that is true if the arms are all parrelell to each other and the ground it should work fine, and usually this is a fine rule to work to normally

But lets face it, if your here your not normal tongue.gif

if u run that level setup u dont have enough front roll center hieght, hence RCA's being so popular. However, because the RCA's go between the steering arm (where the tierod and balljoint are mounted) and the strut it doesnt affect the bump characteristics, if the bump is wrong then the tierod must be raised/lowered in relation to the LCA by either changing the tierod mount on the steering arm or raising/lowering the rack

[sr_rolla]

(quote old thread slydar)

ill have this to add. helper springs. win. my car is set up with a good 3" of droop now, and some helpers springs. everything else is fairly "normal" but wow, big difference. car just as way better manners. havent even had a wheel alignment yet.

[sr_rolla]

(quote old thread biggo)

I have a few things to add too,

AE92 shocks are a no no for droop

A nifty rule i got the other day 1mm = 1/4* deg in toe in/out terms, this is not the be all end all tho.

[sr_rolla]

(quote old thread mattyn)

hey suspension team.

Situation => I'm going to change bushes in the very near future and i was hoping for some guidance. I was looking to go for Poly Urethane… Given availability Super Pro seemed the best option. 2 issues here..

Issue 1:
QUOTE
don't replace the bushes in the top passenegr side trailing arm to the diff at each end, the rest of the 5 link is good.

with all the bushes in the rear changed the diff cant pivot properly and to make it do that you need to either remove the top passeneger side bar (not recomended) or drill multiple holes through the rubber bushing.

Im wondering where these notes from another thread will apply.. not sure about this one..


Issue 2:
there are a pair of rose joints at the front end of my car, (name of arms escapes me, they attach from the torque box to the LCA, sorry.. .maybe castor arms??)
is this what you refer to here..
QUOTE
is get some nice bushes, some corona front arms, some RCA's and a rosejointed castor arm arangement.
I’ve got level LCA’s done with RCA’s and I think if I’m using the right name I’ve done the rose joint you refer to.
So the question is:
If I was to Leave the control arm bushings and only do the rear would this have a negative (perhaps unbalanced) effect.. IE: would it start to feel sloppy at the front once the rear is done????

Thanks for bearing with me on this one..
Matt.

[sr_rolla]

(quote old thread konakid)

QUOTE (mattyn @ Nov 18 2008, 01:29 AM) *
hey suspension team.

Situation => I'm going to change bushes in the very near future and i was hoping for some guidance. I was looking to go for Poly Urethane… Given availability Super Pro seemed the best option. 2 issues here..

Issue 1:

Im wondering where these notes from another thread will apply.. not sure about this one..


I have had Super Pro throughout my car for 40,000km, they are still as new today, made in Japan, very good quality bushes dude, got them from AJPS, full bush kits are about 370 i think.

As for the issue for not replacing those bushes, i just replaced all the trailing arm bushes and the rear end now feels tight. It sounds like a bit of an old racing tale to be honest, too many companies offer full rose jointed 5 links for it not to make enough difference if the rear end has no movement.

That said, poly bushes still offer some give.

QUOTE
Issue 2:
there are a pair of rose joints at the front end of my car, (name of arms escapes me, they attach from the torque box to the LCA, sorry.. .maybe castor arms??)
is this what you refer to here..
I’ve got level LCA’s done with RCA’s and I think if I’m using the right name I’ve done the rose joint you refer to.
So the question is:
If I was to Leave the control arm bushings and only do the rear would this have a negative (perhaps unbalanced) effect.. IE: would it start to feel sloppy at the front once the rear is done????

Thanks for bearing with me on this one..
Matt.


Sounds like rose jointed castor rods and brackets? Those rods that reach diagonally and connect to the lower radiator support chassis rail are castor rods.

A rose joint looks like this, basically a bearing in a carrier

Reduced: 73% of original size [ 700 x 305 ] - Click to view full image


It would feel less direct in the front end if you only did the rears, id recommend definately doing it all at once to make the car feel tighter and more responsive. The front end is equally important as it effects how direct your steering is and feels.

[sr_rolla]

(quote old thread ajps)

just clearing up one thing kona kid said

super pro (imho) worlds best urethane is made in australia and is exported to the world - it is often sold in different colours and with different packaging.

It is also used and often favoured over rubber (which japanese typically used to ALWAYS use) and they advertise in JDM mags - although i think that is resellers in japan advertising (perhaps where the made in japan thing came from)?

[sr_rolla]

(quote old thread mattyn)

yeah, cheers for that kona kid, i was getting it mixed up as sometimes i've heard it called a strut bar. but yeah same thing with two names ive now discovered.
cheers for the heads up on the longevity also, good to hear yours are lasting a decent period.
will go through with the front also, shouldn't make the job too much bigger since ill be under there with penetrating oil and a breaker bar anyway.. tongue.gif


If anyone has heard anything else about this

QUOTE
don't replace the bushes in the top passenegr side trailing arm to the diff at each end, the rest of the 5 link is good.
with all the bushes in the rear changed the diff cant pivot properly and to make it do that you need to either remove the top passeneger side bar (not recomended) or drill multiple holes through the rubber bushing.

let me know.. cheers!!

[sr_rolla]

the theory is that because the upper and lower arms are at different lengths the diff will try to twist itself as the left and right ends move in different directions (ie: the left moves up and forward while the right trys to move back and down). When u convert the rear end to more solid bushings the diff can no longer pivot in its bushes so the car has a tendency to lift wheels and push understeer. If u drill out the upper bush as u described the diff can pivot as it is meant to do.

What i would suggest doing is trying the drilled out upper arm 1st and if u feel its a problem later on, get some new bushes.

[sr_rolla]

(quote konakid)

QUOTE (sr_rolla @ Nov 19 2008, 06:14 AM) *
the theory is that because the upper and lower arms are at different lengths the diff will try to twist itself as the left and right ends move in different directions (ie: the left moves up and forward while the right trys to move back and down). When u convert the rear end to more solid bushings the diff can no longer pivot in its bushes so the car has a tendency to lift wheels and push understeer. If u drill out the upper bush as u described the diff can pivot as it is meant to do.

What i would suggest doing is trying the drilled out upper arm 1st and if u feel its a problem later on, get some new bushes.


Is this why Cusco offer a 5 link with a rose jointed diff end and bushed body end? Seems like that would be an ideal setup.

[sr_rolla]

(quote old thread mattyn)

QUOTE (sr_rolla @ Nov 19 2008, 05:14 AM) *
the theory is that because the upper and lower arms are at different lengths the diff will try to twist itself as the left and right ends move in different directions (ie: the left moves up and forward while the right trys to move back and down). When u convert the rear end to more solid bushings the diff can no longer pivot in its bushes so the car has a tendency to lift wheels and push understeer. If u drill out the upper bush as u described the diff can pivot as it is meant to do.

What i would suggest doing is trying the drilled out upper arm 1st and if u feel its a problem later on, get some new bushes.


so i guess the question now would be WHO ELSE RUNS A POLY URETHANE BUSHED REAR END??? and what have you found...?

im under the impression that Poly urethane bushes still have some give.. wouldn't the rotational/pivot issues only really come about with a rose jointed un-equal length setup? ie no movement??

[sr_rolla]

(quote old thread highlife)

QUOTE (sr_rolla @ Nov 19 2008, 06:14 AM) *
the theory is that because the upper and lower arms are at different lengths the diff will try to twist itself as the left and right ends move in different directions (ie: the left moves up and forward while the right trys to move back and down). When u convert the rear end to more solid bushings the diff can no longer pivot in its bushes so the car has a tendency to lift wheels and push understeer. If u drill out the upper bush as u described the diff can pivot as it is meant to do.

What i would suggest doing is trying the drilled out upper arm 1st and if u feel its a problem later on, get some new bushes.


I have heard through some guys that race 86's in Australia that you shouldn't do a full unequal length rose jointed trailing arm set-up as it can bind up under certain conditions and cause some unpredictability - your explanation above makes a lot of sense and I can see how it would happen now. Apparently this is solved by going to an equal length rose jointed setup.

[sr_rolla]

(quote old thread redsprinter)

SR_ROLLA ,

just read the whole thread .. learnt alot and cant wait to try some stuff. but i was wondering if you have and assume you have read "fred puhns how to make your car handle" . Just wondering if this would be a good book for someone who wants to learn about suspension setups and doesnt know all the tecincal lingo ..sorta like suspension for dummies.

for the suspension team -

will having too much lock (i do abit of dirfting) cause any negatives to other suspension area for grip driving????

[sr_rolla]

(quote old thread chrisso)

I have poly bushes all round and it was a significant improvement. However, I was starting from a pretty low base as the rubber bushes were completely shagged. The rear is a bit hard, but that has more to do with the overly stiff (temporary) pedders dampers. btw, I used nolothane as the price/availability suited me at the time.

Chris.

[sr_rolla]

how to make your car handle is an awesome book, just b aware that everything is in imperial and the aerodynamic stuff is pretty outdated

Highlife- yes, if u run an equal length setup none of the issues described above happen anymore as there is no longer conflicting arcs in the 4 link.

Red Sprinter- i cant see having to much lock being an issue unless the front end is able to invert. There is no way this can happen with a standard style strut (ie, XT130/AE86 style strut as opposed 2 S13 gear)

With the issue of running a drilled out upper left arm, instead of talking about if it does or doesnt make a difference, is there somebody out there in the real world that has a fully rosejointed rear end? If so, could that person go 2 the wreckers and get an upper arm out of a KE70/AE71/AE86/RA40-60/Corona and drill it out and see what it does? Cant cost more than $20 and an hr or 2 to finallise weather it works or not

[sr_rolla]

(quote old thread slydar)

bill sherwood says it doesnt work and is borderline dangerous.

i reckon its pretty obvious its a shit idea.

[sr_rolla]

QUOTE (slydar @ Nov 22 2008, 02:37 PM) *
bill sherwood says it doesnt work and is borderline dangerous.

i reckon its pretty obvious its a shit idea.


good for bill sherwood, plenty of cars come out with a 3 link, it works, works well and is plenty safe. The theory behind it is solid and its easy to do so whats the problem with giving it a go?

[sr_rolla]

(quote old thread samQ)

ah I love this thread, I wanted to expand on the whole equal length bar thing with an old thread from toymods that I made a while back:

when the diff when it goes up in a car such as an ae86 the diff rotates and pinion angle changes as it moves up due to two different arc of movement from the unequal length top and bottom arms. This is all good and all but what happens when one side is level and the other side moving up? it doesnt seem like a problem at first but looking closer because of the different axis' of movement between the top and bottom arms it wants to rotate but one side does not because it is at a neutral position. As far as I can see it on one side will in that situation want to stay as it is and the other will try and twist.

I can only see this be taken up in the bushes and hence why its recommended to drill out the upper top left trailing arm bushes when the rest are upgraded. But what happens when rose joints (spherical joints) are used in the complete rear end? without any deflection allowance I can only see that one side of the diff can move up by twisting the diff housing or testing the sheet metal floor of the car.


also theres the article I wrote in the faq:

Multilink rear end tuning


I am not an expert though

[sr_rolla]

(quote old thread mattyn)

decision almost made... tongue.gif.. i have rose jointed bars with old rubber bushings at the other end so i'm thinking about using these. yes its still an unequal length setup but I'm hoping that with the following it'll be a good improvement.. Just wanted to run the idea past you all. Thoughts?

Trailing arms: rose joints (diff) and NEW rubber (body)
rose jointed castor arms.
poly-urethane LCA pivot
poly urethane panhard mounts
poly-urethane sway bar mounts


The sway bars bring me to my next question:
I have Cusco strut bracing front and rear.. the sway bars are stock as far as i can tell.
With the upper bracing will this cause an unbalanced effect with the stock sway bars or with the new less pliable polyurethane bushes holding them in are these satisfactory....???

i dont want to do things twice so if i was to find that i wanted to replace the sway bars at a later date i would probably do it now to save buying another set of larger diameter bushes... were all on a budget right!

thanks again for your help!

[sr_rolla]

get a rosejointed panard bar and some cusco/whiteline sway bars from ajps and i would call that a real decent setup.

[sr_rolla]

(quote old thread slydar)

QUOTE (sr_rolla @ Nov 23 2008, 07:15 PM) *
good for bill sherwood, plenty of cars come out with a 3 link, it works, works well and is plenty safe. The theory behind it is solid and its easy to do so whats the problem with giving it a go?



yeah. a 3 link set up. with the 3rd upper link in the middle is semi common (though more so in off road applications), but i cant clearly remember seeing it set up they way you described on any car ever.

the asymmetry of the modified "3.5" link 86 set up is ridiculous, we're not building circle track cars.

you asked if anyones tried it and i just mentioned ive read about some one who had, i honestly dont rate Bill that highly either. but his reports say it was a serious step backwards. if he'd have said something like "hmm not sure, different but hard to say if its better or worse" then maybe. that and it just seems so rigged.

you dont have to think about it for very long to realize its going to give at best somewhat unpredictable handling.

maybe you should try it?

too late for me, that craps all gone in my car.

i agree for sure, if youre going to stick with the un equal arms, then some compliance is worth having. its common knowledge that changing to all rose joint makes the car even more twitchy than it already is. but the rubber bushes already have a lot of compliance.

[sr_rolla]

the crown i have in the shed has a 3 link setup, it looks exactly like the rolla/sprinter setup only with 1 arm missing and everything is a little bigger (obviously, the things a tank).

It handles quite predictably, isnt bias to left or right corners and is dead stock and has been for 34 years. The only thing that makes it not nice is the whole cars general squishyness (being a comfort bus) and the incredibly homosexual recirculating ball steering. It smooth as hell, isnt twitchy even at the limit (dont ask) and doesnt have that shitty push understeer at the limit that rolla's have.

I'm not doing it to mine because im going = length and cant be bothered to be honest.

On a side note, i do like the way you did your 4 link slydar, different.

[sr_rolla]

(quote old thread ajps)

steering box is so shit!

anyone driven a DR30 or something with Power steering box? so fail

[sr_rolla]

(quote old thread mattyn)

Ok, cheers for the advice.

another thought regarding alterantives due to parts availability/the lack of.
called toyota: Can only buy the bars with new bushes in them.. this is not what i need/expensive!!
called fulcrum: they have polyurethane at Duro 70, which old mate touted as the equivalent to rubber.

also here is some info i found.
" Note that poly bushes come in (at least) three durometers, or hardnesses. Duro 70 is much like rubber in its hardness, which duro 80 is a little harder and is most commonly used. Duro 90 is harder again. Importantly, the higher the duro, the more easily the bush will pivot on the crush-tube so if low stiction is needed when under load, a higher duro should be used. "
[http://autospeed.com/cms/A_2833/article.html]

so for those in the know regarding polyurethane bushes: if i was to go for this duro 70 polyurethane at the body end of the trailing arms would this act as a equivalent alternative to rubber for my purposes.
(note: other end is rose.. must serve for compliance in an unequal length setup AND vibration and noise suppression.)


Oh and if any one knows of rubber bushes which fit into the trailing arms this would be GOLD!!!

thanks all for the replies and advice!


Matt

[sr_rolla]

(quote old thread slydar)

TRD

[sr_rolla]

(quote old thread fantapants1)

did u have a bad day dim.... all im seeing is one word answers tongue.gif


usefull one word answers though .... 2thumbs.gif

[sr_rolla]

Rationing sylables perhaps? tongue.gif

Mattyn: pretty much anybody who makes eurothane stuff should be able 2 make you something to suit if they dont have stock already. Like slydar said tho, pretty sure TRD would have what u need in stock

[sr_rolla]

(quote old thread slydar)

trd make a rubber bush. its not poly. theyre not cheap. but theyre also very well regarded. chris oshanessy took poly bushes out of his IP car and put them in and said they were better. i think he said he felt there was less "rear steer".

seeing as youre servicing a 4 link set thats already worth money, i think itd be pretty easy to justify the expense. try palmside (also the quaife distributor) in NZ, they might be able to sort you out, if you dont have a better trd source.

[sr_rolla]

Good work on copying the old thread over!!

I am very keen to get my hands on a cusco rear RCA that does the same thing you described, lowering the diff end panhard rod mount so its basically flat, but im doubting it would make much of a noticeable difference.

Any one tried it?

Firstly, thanks for breaking the continuity of it all, secondly, yes it does make a noticable difference, it makes the diff stay as close 2 centered as possible if the bar is level.

Not as good as a watts linkage setup but its still pretty good.

[sr_rolla]

Good work on copying the old thread over!!

I am very keen to get my hands on a cusco rear RCA that does the same thing you described, lowering the diff end panhard rod mount so its basically flat, but im doubting it would make much of a noticeable difference.

Any one tried it?

Firstly, thanks for breaking the continuity of it all, secondly, yes it does make a noticable difference, it make the diff stay as close 2 centered as is possible with a panard bar if the bar is level

[Sam-Q]

would there be any merit to using possitive camber roll center adjusters to move the scrub radius closer to neutral and then using longer control arms to correct the change in camber? This would be a crude way of doing what TRD did yes?

[sr_rolla]

yeah that would work, i have thought about the idea but i came up with the same conclusion, yes it is a bit crude.

Also, there will more than likely end up with clearance issues with regards to the brake disk.

[Sam-Q]

I will have a look and see how far my arm is off the disk, so have you measured how far the scrub radius is out with different wheels on your car? I am unsure of how you could even easly measure it.

[sr_rolla]

i have no idea how to acurately measure scrub radius to be honest, i'll have 2 do a bit of reading arfter i recover from nye methinks

[keiichi]

that was damn awesome thanx for putting that up... answered alot of questions ive always had... in short i suppose you want all arms to be parallel to the ground yes?

regarding the 4link on a live axle and in relevance to drifting... if youre taking a left corner (grip) the diff will pivot so that it is also pointing left no? which will then in turn bring the rear end in towards the corner and therefor causing you to turn in harder to make the corner so on so forth more stress on the front and therefor understeer... right (like the opposite of what all wheel steer is supposed to do)? so, very bad for grip... but would you agree that it would be better for drift? going around the same corner at full lock sideways, under throttle, having the diff angle like that would cause the diff to want to centre the car eh.... so more stability? haveing the diff angle point up would also cause more tyre spin under accel? any of this apply to IRS?

regarding scrub radius... bolt on spacers would cause WORSE handling no? better track but horrible scrub radius... this relevent to the rear?
correct me if im wrong but using s13 suspension in the front would be beneficial for scrub radius... whats your opinion on s13 suspension in corollas/sprinters?

[sr_rolla]

generally, keeping the arms parralell to the ground or slightly off parrallel (so when the car is loaded of hits a bump they are parralell) is a good start yeah. In drift i would still aim for a paralell setup, its more predictable and easier to tune (ask slydar). I personally have no idea if pinion angle would affect an IRS rear, my thinking says that it shouldnt but i could be wrong.

With the silvia front end, i personally think it is a horrible setup, ball joint is at a shitty angle, tie rod end is at a shitty angle and the steering has the ability to invert or jam on full lock. Basically you are fixing the scrub radius problem by creating 3-4 new problems. I know i will cop crap over this but these are the facts. I would suggest a strut based around a AE86 style strut (XT130 etc) and make a good coilover arrangement using a quality damper based of that, then get rose jointed caastor rods (cusco make the best setup ive seen) and some new bushes throughout the front end. Other than that, GReddy make a complete replacement system for sprinters that is quite good but expensive. for the rear get a set of Gilly's GAZ coilovers and work from there.

[drifte.au]

Brilliant thread.

What are some reputable workshops in melb that really know these cars?

Centreline have any idea>?

[sr_rolla]

No idea man, i'd suggest asking in the vic forums

[drifte.au]

Nps, didnt realise you were in NSW.

:)

[sundee]

[QUOTE=sr_rolla;2477]gunbz-r don't assume that a square car is the best way to go, the best ratio is 1.7:1 as in 1 being the track width and 1.7 being the length so for example if the car is 2m wide for example the wheelbase has to be 3.7m long for the best handling. A ae86 has this ratio standard, if you try and make the car more square it will turn in really well and be very stable at slow speeds but be extremely nervous and difficult to control at speed. QUOTE]

This thread is awsome.. i was thinking of going S13 front recently because im going to fit R32 brakes all round, thought it might save making a custom bracket for the front caliper. but after reading all the geometry affected in throwing all the s13 gear in.. im now sticking with the 86 setup... ive had the chance to look under beau yates car and appart from rose joints and a few adjustable bits its all 86 gear.

Ratio... this is great ive never heard this before, just wondering with Track and length where are they both measured from and to?
track from hub outer to outer? and length hub center to center?
how much increase in track can u have before it has an adverse affect on handeling?
i dont want to run any +ve offsets .. dish is the win ...

and if going big brakes what struts should i use.. something with a tougher stub axle

hmm 16's and 250rkw... yummm!!

[sr_rolla]

Its measured from the center of the tyre contact patch to center of tyre contact patch. For the struts i'd use either the XT130 strut and the hilux/pug brake upgrade or use RA40 celica struts and make everything custom.

knowing how much is to much with regards to track is kinda touch and go, it takes testing and what not. What i would do, instead of running massive negative offsets, run stupid fat wheels. that way u have the dish but the center of the contact patch is still pretty close to where it should be.

[anastasios]

is it worth buying trds or would it be smarter to buy a shock like bilstein from australia that is able to be rebuilt?

[sr_rolla]

personally i'd go with either bilsteins or koni yellows, you can easily get them, they are locally rebuildable and are both of decent quality.

I would look around and see if there is a company locally that can rebuild TRD's tho, i think they are tokicos (not sure). if they are then im sure there has to be someone in aus that rebuilds them

[john84ie]

been searching for awile,looking for best allignment setting for fast/sideways road use. gunna get my ke alligned,what settings should i ask for?my front setup is

tein camber tops
ae86 coilovers with agx ajustables
ae86 power steering arms
ttt rca's

thanks in advance

[trikzlane]

i recommend,
-2 to -2.5 camber
max out castor (its like +3 standard arms)
0 to -1 out total toe

i have test alot of different setups on my car cause i was a wheel aligner and have found this setup to be the most responsive yet still streetable

[sr_rolla]

agreed, i run pretty much exactly that, slightly more agressive on the neg and castor but i run semis so i can use it

[john84ie]

exactly what i was after,thanks dudes!how much is a alignment these days?so they'lajust everything there for me,cause i just through all the bits in without setting anything and its driving very badly

[Hachi_Tom]

is +3 on standard ke arms?
i have +5 on standard 86 arms.
but what everyone has said is around what i have been hearing to.

[trikzlane]

yeah on ke castor arms man.
they can cost anywhere for $40 to $65 depends where you go and who you know :)
just tell them the specs you want and ask for a printout when there done to ensure its done properly