Spring Rates

[Dan_AE86]

Im getting front coilovers and rear springs, other gear etc. from AJPS real soon, BUT.

i need to decide on spring rates, the car is my everyday driver/weekend hell raiser which i drive 70kms return for work each day on the ballina/byron road (which is shit). Use will be good street car, 3-5 meetings a year hill climb, some track drift and heaps of Street Drift/hill runs (on a track of course!) :rolleyes: .

So my question is what spring rates does everyone run and why!and what they recommend, etc.

NOTE: THIS CAR STILL HAS FULL INTERIOR AND WILL NOT SEE A CAGE (UNLESS SHIT CHANGES.). CAR WILL HAVE A FRONT STRUT BRACE, REAR ONE LATER MAYBE..

Please HELP!

Dan.

[dori_86]

i'd say if ur planning on 5+ hill climbs plus extra curricular weekend action then 8/6 combo is decent, ive had the same spring rate AJPS coilovers and im yet to get to the track,

but its all personal opinion i know of some1 running i think 11 or 12kg in the front of an 86 and was daily driven and they liked it, so just get the norm spring rates and because there coilovers if u decide too stiff/soft u can change the springs

[rthy]

if you drive 70km on a crap road every day then theres no way you would want really stiff springs. Unfortunetly what people think is good in terms of spring rates is very subjective. I made the mistake of listening to the drifters on my fourth spring combination and I bought some 6kg springs which was a big mistake. Not only was my car slower around corner because of the reduced traction but it was horrible to live with. I then just took a gamble and went with a hunch that ws 275 pound/inch which is 4.9kg. I use custom springs for the back that are round 3.3kg/mm.

Perhaps you should just have 2 sets of springs? one for daily use and the other for the more serious work. What you need to do is drive someone elses car down that road for atlest 10 min. I drove a car with 8kg springs and it seemded good from a short distance but i know if I kept driving it would of irrited me.

Whatever you do I recomend running 2/3 of the front rates for the back, any different and it may not be neutral.

[Oly AE86]

Agree with Sam and Chris

I drive 50+ Km to/from work daily, and local roads can be very dodgy. Car has full interior and F + R Braces

I am running 350lbs front ( roughly 6kg) and 4.5kg Rears, daily driving + some track work.

I am also using the KYB AGX adjustable damper shock, so I can get the shock just right for the springs. Front feels great on setting 2/4, rear on 1/8 :o

I wouldn't go any stiffer for the street around here, especially the rear as it has very little weight and bounces a fair bit on the rough stuff.

Having said that, its got some wicked traction and a little squat giving me heaps of grip.

If you want comfort for driving, I would go 2 sets of springs, maybe 4 - 3 for the street, and 8 - 6 for drifting/track stuff.

[ke70dave]

agreed with oly

i have 11kg in my car atm at the front (waaayy to stiff), i have 8kg to go in though..

ive driven alot in bahnuggets car, with 8kg in the front and approximately 6kg or so in the rear.

its pretty good to drive in, if you remember that its a "race car". its by no means comfortable, but its good.

if i was gonna drive my car every day to work (i just walk to train station atm) i would definitely look at getting another set of springs, say 5kg and 3kg or so. with some decent shocks good handling can be achieved with comfort.

just a quick question on this topic

if one was going to go for maximum grip (disregarding comfort), what spring rates do you think you recommend????

[Konakid]

If its drift and hills, 8 and 6

If its hills, 6 and 4.5

also, Swaybars win, get them.

[Dan_AE86]

just a quick point to clear up a few little things...i really want the car's setup to be drift orientated because fuck its fun, as for grip racing id probly leave it setup for drift because im not serious about times im just in it for the fun and experience..and as for the two sets of springs idea i dont wana go down that road because i dont wana change them all the time/spend the extra money..ill see just how bad it is, if i cant stand it then yeah ill go two sets.

is there a need for adjustable shock?does it make THAT much difference?just the front or rear too?

BTW im leaning towards 7kg Front and 5Kg Rear...what do people think?

also i dont want to have to seam or spot weld anything or go a roll cage so is this too much KG?

Dan.

[rthy]

oly ae86: the fact that you find that dampner setting is right seems to sujest to me that your rear spring rates are too stiff. But I could be wrong.

ke70 dave: maximum speed specifiactions change from corner to corner. Everyone seems to say 6kg but that would make my car slower because of the loss of traction. Basicly good surface = high spring rates and dampening and poor surface = soft spring rates and dampening.

kona kid: I tottaly disagree with you on this one, I know for sure that 7kg spring would make my car slower where I love, you see the hills where I take my car arnt that well mainaned so I would have to go slower to have the same amount of traction. Also that combination of 8 and 6 I think from my personal experience in my car would cause big oversteer. As for anti roll bars, I havent tried changing them personally because quite a few people who race sprinters seem to agree stock is the best size.

dan_ae86: I think that spring combination may cause you a fair bit of oversteer but it depends on many factors. Also whats KG stand for?


I want to ask you guys something, how many of you have tried multiple different springs in an effort to get their car cornering the quickest? (that means neutral)

[Konakid]

Going by the two thirds rule the rears should be two thirds of the fronts ie 8 and 6, although many japs alter this slightly ive found.

While this setup is too stiff for genuine hills runs in Australia, it doesnt make that much difference over 6 and 4.5, realistically.

I mean, 6 and 4.5 might chop 2 seconds off your local 1 minute hills run, if your pushing that hard your taking it waay too seriously, seriously! So in theory 8 and 6 is a 'sacrifice' i guess for hills, but in the real world it really doesnt matter when your going for a punt along your fave road.

Swaybars make the biggest difference, they make the car stick so hard, but with the flick of the wheel, it will snap straight out into smooth oversteer. With the whiteline rear bar ive got atm anyway. Im currently in the market for a front one, 24mm.

go 7 and 5 if you have to but realistically id just go 8 and 6 and put up with it, its fine for hills. One thing though, is make sure you dont dump the car, limiting suspension travel otherwise it will feel and ride much stiffer than it should be as the shocks will be at the bottom of their stroke at standstill. The KYB's form AJPS are stiff enough for 8 and 6 so they match up quite well. Just keep sensible ride heights and it'll be fine (not stock obviously!)

There was a big thread on this but i cant find it anywhere, i thought it was in the motorsport section but couldnt find it...

[roadsailing]

while on the topic of travel, make absolutely certain you have enough rebound travel, as this is crucial to comfort and handling.

i'd reccomend 6 front 4 rear or therabouts, my car has 5.8 front and 4.3 rears, its fine on the road and reasonable on the track.

i calculated the natural frequency this gives, and according to some oldish book on suspension it is on the high side what you would want for a circuit car with no aero.

[Dan_AE86]

dan_ae86: I think that spring combination may cause you a fair bit of oversteer but it depends on many factors. Also whats KG stand for?[/b]

KG=Kilogram/mm or something..someone will correct me!
also i want oversteer (i want it to be setup for drift/street), just not understeer (i already have heaps of that!ha)


Swaybars make the biggest difference, they make the car stick so hard, but with the flick of the wheel, it will snap straight out into smooth oversteer. With the whiteline rear bar ive got atm anyway. Im currently in the market for a front one, 24mm.

go 7 and 5 if you have to but realistically id just go 8 and 6 and put up with it, its fine for hills. One thing though, is make sure you dont dump the car, limiting suspension travel otherwise it will feel and ride much stiffer than it should be as the shocks will be at the bottom of their stroke at standstill. The KYB's form AJPS are stiff enough for 8 and 6 so they match up quite well. Just keep sensible ride heights and it'll be fine (not stock obviously!)

There was a big thread on this but i cant find it anywhere, i thought it was in the motorsport section but couldnt find it...[/b]

Yeah i couldn't find it either hay, what size rear swaybar are you using?24mm a good size you reckon?i take it your car is setup for drift?

also define 'dumped' how long are you talking here, i want somewhere around in line with the tyre with 195/55/R15.

Keep it all coming fellas...

[ke70dave]

while on the topic of travel, make absolutely certain you have enough rebound travel, as this is crucial to comfort and handling.[/b]

by this do you mean "droop" ? (heard that term somewhere)

so how far the wheels drop down when you jack the car up?

if so, what is considered "enough" at the moment my coilovers/wheels probly drop down about 5 cm after i jack the car up, is this considered enough?

this is at the front, the back problable drops down close to 10cm or so

sorry for offtopic, its kinda related though...

[Dan_AE86]

thats ok, bit more knowledge never hurts on forums..thats how we learn (if some is true, ha.)

So. Who knows good swaybar sizes for drift setup?and is that too low?is there a level at which it makes things worse?

Dan.

[Konakid]

standard is 14 or 13mm cant remember, whiteline is 18mm, which is sweet, although i think cusco do a 19mm.

24mm on the rear is massive, thats what the whiteline front one is.

That ride height sounds sweet. Just make sure you use short stroke shocks and it should be fine.

[mikewestphoto]

Dave, yeah, droop/rebound stroke. Ideally you want 4 tires on the ground at all times with the spring pushing the tyre into the ground. Not much point having

I punched in rough measurements off my car and disregarding roll stiffness added by swaybar, an 8/6.5 combo gets me a roll gradient of 1.76deg./g which about as hard as you want to go according to race car vehicle dynamics. Ends up with a front roll rate of 51000lb.-ft/rad and 20000lb.-ft/rad. It probably doesn't mean much to a lot of people but I like it the way it is.

If you want the car to be oversteery, fit the 18mm sway bar on the rear and leave the front one stock and get your usual 7/5 or 8/6 spring combo.

[harrygat69]

standard is 14 or 13mm cant remember, whiteline is 18mm, which is sweet, although i think cusco do a 19mm.

24mm on the rear is massive, thats what the whiteline front one is.

That ride height sounds sweet. Just make sure you use short stroke shocks and it should be fine.[/b]
13 or 14mm rear depending on model :)

i dont consider the 24 mm front sway bar to be massive in fact im seriously considering getting the 27mm its all to do with how much force is acting on ur tyres ie: grip level use shit tyres soft suspension will do use semi slicks and the suspension rates need to be raised dramaticly
do short stroke shocks change suspension behavior other than keeping the springs captive ?? i think not

KYB excell g shocks are a standard replacement shock and using shocks from other cars is not a good practice as there are not setup correctly for the vehicle weight, spring rates and unsprung weight

stiff spring rates feel very compliant and comfortable when using a high quality correctly setup shock like bilstein or similar

my personal setup for street car with good over steer is 6kg f+r with the whiteline sway bars on full stiffness front and 2nd stiffest rear and bilstein shocks all round and good tyres for the front is a must anything older than 12 months old is not a good tyre

oh and add some camber strut tops and wind the castor rods right foward and get a wheel alignment

cant wait for some of the replys now... :P

[Konakid]

<{POST_SNAPBACK}> (index.php?act=findpost&pid=416719)
standard is 14 or 13mm cant remember, whiteline is 18mm, which is sweet, although i think cusco do a 19mm.

24mm on the rear is massive, thats what the whiteline front one is.

That ride height sounds sweet. Just make sure you use short stroke shocks and it should be fine.[/b]
13 or 14mm rear depending on model :)

i dont consider the 24 mm front sway bar to be massive in fact im seriously considering getting the 27mm its all to do with how much force is acting on ur tyres ie: grip level use shit tyres soft suspension will do use semi slicks and the suspension rates need to be raised dramaticly
do short stroke shocks change suspension behavior other than keeping the springs captive ?? i think not

KYB excell g shocks are a standard replacement shock and using shocks from other cars is not a good practice as there are not setup correctly for the vehicle weight, spring rates and unsprung weight

stiff spring rates feel very compliant and comfortable when using a high quality correctly setup shock like bilstein or similar

my personal setup for street car with good over steer is 6kg f+r with the whiteline sway bars on full stiffness front and 2nd stiffest rear and bilstein shocks all round and good tyres for the front is a must anything older than 12 months old is not a good tyre

oh and add some camber strut tops and wind the castor rods right foward and get a wheel alignment

cant wait for some of the replys now... :P
[/b]

Heres my reply, haha nah, interesting dude,

With regards to the 24mm swaybar, i was reffering to it being used on the REAR which would be far to large. as far as the 24mm FRONT being to small, what springs are you using with that size?

Definately, softer compund/more grip tyres allow for a stiffer set up.

I believe short stroke shocks do change the suspension behaiviour as when on a lowered car they are kept within their working range, i.e arent 60% loaded when stationary so that the rebound is way to quick when a bump is hit etc.

Yes the KYB excel g is a standard replacement shock, as it is from a heavier car all the factors you have described have been considered, eg. They wouldn't just uprate the stiffness to suit the heavier car in question, they also up the rebound stiffness to compensate. the length of the shock would also be adjusted to suit the shorter travel springs on said heavier car.

Yes stiff springs do feel very compliant when used with a correctly setup shock, i have been in a t 18 with 6kg rears and super short KYB excel g sierra's which rode almost as smooth as stock, seriously. On the subject of Bilstiens, yes they are a very very good performance shock however they also make OE shocks, as does KYB.

6kg springs front and rear would be overkill, i think a nicer combo to drive with would be 6 and 5 with a rear swaybar to make it oversteery.

[roadsailing]

aim for between 1/3 droop 2/3 bump and 1/2 1/2.

droop is how far the wheels go down when you jack it up, bump is how far the wheels go up before hitting the bumpstop.

[RobertoX]

BUMP

[roadsailing]

BUMP[/b]

bored dave? :lol:

also known as "bang" and "clunk"

[RobertoX]

<{POST_SNAPBACK}> (index.php?act=findpost&pid=416719)
standard is 14 or 13mm cant remember, whiteline is 18mm, which is sweet, although i think cusco do a 19mm.

24mm on the rear is massive, thats what the whiteline front one is.

That ride height sounds sweet. Just make sure you use short stroke shocks and it should be fine.[/b]
13 or 14mm rear depending on model :)

i dont consider the 24 mm front sway bar to be massive in fact im seriously considering getting the 27mm its all to do with how much force is acting on ur tyres ie: grip level use shit tyres soft suspension will do use semi slicks and the suspension rates need to be raised dramaticly
do short stroke shocks change suspension behavior other than keeping the springs captive ?? i think not

KYB excell g shocks are a standard replacement shock and using shocks from other cars is not a good practice as there are not setup correctly for the vehicle weight, spring rates and unsprung weight

stiff spring rates feel very compliant and comfortable when using a high quality correctly setup shock like bilstein or similar

my personal setup for street car with good over steer is 6kg f+r with the whiteline sway bars on full stiffness front and 2nd stiffest rear and bilstein shocks all round and good tyres for the front is a must anything older than 12 months old is not a good tyre

oh and add some camber strut tops and wind the castor rods right foward and get a wheel alignment

cant wait for some of the replys now... :P
[/b]


kyb excel g shocks are awesome quality and stand by them, i have been to the track many time with these shocks and hills, oh and daily driven

having said that i have had bilstein in a car they are good obviously, but i think they have a bit of a wank aura around them

bit like snap on tools, the best yes, but a $5 spanner can undo the bolt

and if you have snap ons you want to justify the cost and think you are the bomb fizzle, like i did oh yeah

the law of diminshing returns comes into play here 400 set of shocks are 90% as good as a set of $1400 shocks its the simple truth, and that is before getting into science, and we need to remember we are talking about $500 cars here not F1 cars


using shocks from other cars is cost effective and is a method employed by TRD, Whiteline and a host of other companies.

at the end of the day if you are good enough driver and the body of the car is under control you can drive around problems

just look at simon michaelmores car

-6 camber, 12kg springs, with s/hand shocks of unknown type, low as low 5 mil toe out

and you know what even tho he is a massive fuckhead, he was actually exciting to watch unlike most of the ass draggin d a 'drifters'

^ sorry about going off topic :)

[RobertoX]

lol yes bored, seeing the BUMP and DROOP lol

anyway beddy byezzzzz




<{POST_SNAPBACK}> (index.php?act=findpost&pid=416798)
BUMP[/b]

bored dave? :lol:

also known as "bang" and "clunk"
[/b]

[biggo]

i currently run 4.5kg front and 4.5 in the rear. My personal opinion is its wayyy to stiff for daily if you wind the rebound all the way out on koni's.

Hills are another story tho :)

also sporting double rear swaybar and soft tyres

[rthy]

who is that simon guy?

[ae71]

the driver i believe.

i have some unknown springs that i found in the shed left over from one of my dads projects.

they are a lot thicker than my TRD 6kg springs i have here that will go in. I'm assuming that are a minimum of 8kg as they do not compress at all, they are also very short (i cut them in half) so i have no front end stroke.

i hear what your saying David and i agree with you to some point. a well setup car will be able to be able to driven faster then a poorly set-up car. although a compromise is sometimes not as bad as you may think. really depends how serious you are.

i have a heaps stiff front but only cut springs in the rear making it very unbalanced. when i first drive the car when you tuned the car the back end would way a lot making it feel like it way sliding (a very weird feeling :S ). although they are badly matched and i have standard shocks all around im still able to push the car a few seconds quicker in the hills with these.

they have there draw backs, for example i was braking up hill and there was some corrugations in the road, it made the front end bounce hopping along slightly locking the fronts each time it bounced (about 5 times). its typically not too bad for bounce on the hills but on the highway/town it can be quite rough. its my daily driver and there are more unfriendly parts of the car which are more of a concern than the stiffness.

[ae86trueno]

7kg front 6kg rear,
The TRD race shocks are fantastic, we were able to play around the settings and dial them in
and made a full second around wakefield i the end.

Definatly needs some bigger roll bars though.

[Konakid]

7kg front 6kg rear,
The TRD race shocks are fantastic, we were able to play around the settings and dial them in
and made a full second around wakefield i the end.

Definatly needs some bigger roll bars though.[/b]

Any idea what sizes your going with? I'm interested to know, cheers.

[rthy]

konakid: which suspension setups have you tried as in different spring rates or things like that.

[ghetto ke]

Stock AE86 spring-rates were about 1.7-2kg/mm (100-115lb/in) from memory and rear was actually stiffer than front.
Reasonable street/hills upgrade is about 6k Front, 4.5K Rear - which is what I used (with TRD shocks) before I switched to coilovers.
Most drifters run 8K front and 6K rear which gets a bit bumpy for a daily. I am currnently using 10K front, 8 K rear for circuit/hillclimb but this requires semi race rubber something like Advan A048. May try Toyo R888, Bridgestone RE55 or Dunlop Direzza and see what tyre matches better...

[RobertoX]

who is that simon guy?[/b]


simon michaelmore

you need to get out more :P

[rthy]

who is that Dave? no I cant say I get out much

[Konakid]

Simon michaelmore is drifter....

I have had 6 and 4.5kg in my car, changed to 7 and 6, and have purchased some 8kg fronts for when the car goes back on the road. Also have whiteline 18mm rear bar.

[ae71]

what front swaybar do you have?

[RobertoX]

stock

soon to be 24mm

[ae71]

wouldn't a thicker rear swaybar with a stock front one make it unbalanced are rather oversteery?

not really what you want on a "hills car"

[RobertoX]

wouldn't a thicker rear swaybar with a stock front one make it unbalanced are rather oversteery?

not really what you want on a "hills car"[/b]


it is used for sliding in the hills and very competitively too so the rear has to be firm to initiate from speed

he runs high grip rear tyres for much bigger angles

no delamed 13s here!

[ae71]

ah fair enough, i though the idea of his car was to grip not slig.. thick rear swaybar would defiantly be the way to go.

drove a car with 8 & 6 with a 18mm rear swaybar and it was so taily it was stupid!

[RobertoX]

can also depend on alignment and tyres

lots of variables

[rthy]

a bit off topic but I am thinking of changing my sprinters rear camber to -1 which is the max I hear

[ae71]

they where some ordinary 185's but with low power and an open diff it would slide by just turning and slight throttle, not with a lot of speed or particularly high front end grip either.

[Konakid]

My car is dwipt but i still hill run it, see? Just drive around the stiffness, not that hard really!

Have decided to leave front swaybar stock, will see how it goes with 8 and 6 and a rear bar.

[ae71]

Fair enough, I'm keep to experiment more with my suspension when I get more of it...