Suspension Attention!

[HYPNTK]

Hi, guys...trying to organise my suspension setup and am at a crossroads sort of. I don't just want to ring up a place and say I've got "X" amount of dollars, give me rose jointed this and coilover that simply because I dunno what the hell everything does and why some stuff is so expensive.

Firstly, whats the difference between coilovers and other types of suspension. User; grassworksgarage mentioned something about most people going coilovers on the front but not at the back coz of stiffness (i think thats what he said)...

what the hell is the difference for the above and the pro's and cons?
also all these other ad-ons...panhard rods, rose jointed 4 link adjustables, rca's etc...help!! what do these things do and where do they go? i'm starting to think about looking into a short course on suspension at a tafe or something if they have one seriously.

finally what i wanna ask here without looking like a knob at a parts shop is how do i ask for new bushes for my suspension...a friend told me there are bushes at the top of the shocks and the bottom, then you have your ball-joints etc...i want to change my bushes all around with OEM ones coz i think they'll do just as good a job as the nulothane ones with out being so harsh on the ride quality. --> which ones do i change/ask for? and would i be able to change them myself (coz i've heard they are hard to push in). and also would i do this change after or before i upgrade suspension bits?

well, you'll have to excuse the long post but i need all the help i can get as i don't know much about suspension and i get pissed off that i don't have the proper garage type area so i can just fiddle and learn.

[rthy]

wats the car ganna be used for?
if u want ride soft quality from a ae86 u might as well use OEM everything...

[Cerby]

Yeah i think that you are going the same way i am. Your car is a daily driver so it needs to be liveable.
I'm experimenting at the moment with suspension setups. Basically what i'm doing is staying with a seperate shock and spring setup at the back and make some coilovers for the front
'm not using coilovers in the back because i believe i would have to reinforce the metal around the shock top mount to cope with the forces and the cost as well. The main benefits of coilovers that i can see is adjustable height, they take up less space, and easier to swap springs.
The spring rate i have decided on, since i do a fair bit bit of mountian driving and tassie roads are pretty crap, are 5kg front 3kg rear.
I'm basically going to run those rates for a bit and see what it feels like.
And ideally i'm going to get adjustable shocks back and front. That way i can run them reasonably soft then turn them up a bit for the track. Also at the harder settings the shocks will compensate a bit for the softer springs. (I know its not the best way to do it)
Then i plan to upgrade the swaybars and tierods. Then rebush everything. I haven't had much experience with the urethane bushes so it would be interesting to see how much of a difference they make in a vertical direction. Obviously they will make a big difference laterally especially in entering a corner.
Anyway the most important thing is to do what you feel most comfortable with! Get some rides in other cars and compare the setups.
Obviously it would be best to just keep modifying it till your happy with it but the cost of all those parts can be a problem. As you change different aspects of the setup the limiting factors of the existing setup will show through and you will be able to home in on those weaknesses. Just go with what you like driving the most not what is the most popular!
Cheers
Cerby

[Konakid]

Firstly, whats the difference between coilovers and other types of suspension. User; grassworksgarage mentioned something about most people going coilovers on the front but not at the back coz of stiffness (i think thats what he said)...[/b]

Coil over suspension involves the spring sitting on the strut like it usually does although it is much more compact and the rings that the base of the spring sit on allow large adjustments for height which is very useful. The outside of the strut in a coilover is threaded and these rings at the base of the spring can be screwed up and down depending on the ride height you want. depending on how much you spend on coilovers, they can be compression and rebound adjustable to match the springs you choose to run and also have camber plates on top of the strut to adjust camber.

Pros: - Adjustable height, adjustable rebound/compression dampening, adjustable strut tops can be used for camber, probably forgotten a few..

Cons: - They are illegal, cheap ones are shitty and they break, cant fit big + offset rims due to clearance issues (not really a problem)


what the hell is the difference for the above and the pro's and cons?
also all these other ad-ons...panhard rods, rose jointed 4 link adjustables, rca's etc...help!! what do these things do and where do they go? i'm starting to think about looking into a short course on suspension at a tafe or something if they have one seriously.[/b]

Adjustable Panhard rod - bascially religns the diff after lowering your car, the standard one is a set length and pulls the diff over to one side when the car is lowered.

Rose joints - basically an adjustable link on the end of a rod or part which uses a thread and nut to adjust length, also illegal im pretty sure

As for the other stuff, just search the tech articles and read, read, read, thats how you aquire knowledge unfortunately...


finally what i wanna ask here without looking like a knob at a parts shop is how do i ask for new bushes for my suspension...a friend told me there are bushes at the top of the shocks and the bottom, then you have your ball-joints etc...i want to change my bushes all around with OEM ones coz i think they'll do just as good a job as the nulothane ones with out being so harsh on the ride quality. --> which ones do i change/ask for? and would i be able to change them myself (coz i've heard they are hard to push in). and also would i do this change after or before I upgrade suspension bits?[/b]

Pretty much every moving part in the suspension has a bush which after 20 odd years are probably cracked and perished.
Yes you should replace them, although standard ones will feel better, they will wear out again over time and allow more slop/give in the cars suspension. It is best to get proper Nolathane bushes as not only will they last longer but they will make the car feel more "together" and make the handling feel more responsive to driver inputs. If youre going to all the trouble of replacing them, you may as well get Nolathane ones.
You will be able to fit some yourself by some will need to be pressed in by someone who has the right tools. A set of new bushings is a good idea before changing the suspension parts and it won't affect ride quality that much.


well, you'll have to excuse the long post but i need all the help i can get as i don't know much about suspension and i get pissed off that i don't have the proper garage type area so i can just fiddle and learn.[/b]

No worries, its best to just read many tech articles and make sure that they are accurate and build your knowledge on the subject. There is a lot of stuff that I dont know that I wish I did about cars/suspension but over time you just pick up stuff here and there. Perhaps someone with more than my limited knowledge could add to this? Hopefully that helps you somewhat...

[ke70dave]

hey man, what are you currently running in your car ADM stock?

if so, then any upgrade, even small, is gonna make a big difference

coilovers = adjustable ness

you can get just as good as set up with a decent shock/spring combo as you can with coilovers. only advantage of coilovers is you can adjust them.

from what i gather, the main reason people dont run coilovers in the back, is that you need to get your shock mounts on your diff reinforced. and that a decentish shock/spring setup is achievable quite cheaply
can someone confirm this?

now the other things

pan hard rod- you already have one of these, it just stops your diff from goin grom side to side, but when you lower your car the diff will swing one way (only slightly) so you need to get an adjustable panhard rod.

rose jointed 4 link adjustables- rose joints are just really good joints, that dont have any clearance. look them up on the net, you'll get the idea. you already have kinda a 4 link setup, it stops your diff from twisting when you put power down. but if you can adjust the position of the diff you can get different seups, ie if you twist it slightly one way you get more grip, and if you twist it slightly the other way you get less grip. this is how i understand it anyway.

RCA's-roll centre adjusters. im not entirely sure how these work, but they go between the bottom of your strut (fronts where talking about) and the hub thing. they are designed to stop "bump steer". i have never experieced bump steer, but these are suposibly suposed to stop it


bushes-yeah these just stifen everything up to give you more feedback


ohh and who said you need a good workshop to fiddle and learn http://www.ae86drivingclub.com.au/forums/emoticons/tongue.gif get some sockets/spanners and dive straight in http://www.ae86drivingclub.com.au/forums/emoticons/tongue.gif

hope this helps


edit: dagnamit i took to long to post, and people beat me http://www.ae86drivingclub.com.au/forums/emoticons/tongue.gif ive prolly repeated a bunch of stuff....

[Konakid]

Hahaha we all posted within a few minutes, ahh well, have a read through all of em anyway dude...

[ke70dave]

Cons: - They are illegal, cheap ones are shitty and they break, cant fit big + offset rims due to clearance issues (not really a problem)[/b]


they are illegal?? since when?? im in QLD by the way, not sure where you are

[rthy]

yea, any rosejoint stuff and coilovers are illegal it seems, but paint it black and no one ill have to know

[white86]

http://www.grmotorsports.com/

That website has excellent suspension articles. It will explain all the basic concepts and the reasons why people look to upgrade certain parts of their cars.

Go here http://grassrootsmotorsports.com/news/cate...erviews/page/2/ (http://grassrootsmotorsports.com/news/category/articles-interviews/page/2/) and keep going through the previous entries. I remember some excellent stuff on scrub radius among other things.

Rthy, I'm also certain that coilovers are legal in QLD. I think you are right with the rose-jointed stuff though.

[HYPNTK]

wow, what a fantastic response...yes i have to read up on suspension stuff because i have been spending a few months now reading up on engines and mechanical/conversion articles and info and neglected an even more important part.

the car will be used for the street yes but my primary goal is for it to be competetive on the track without being unbearable on the road.

as far as bushes go the reason why i thought of getting oem is because i read somewhere that the difference in handling is negligable and new oem ones will be an improvement and not be as rough on the steering and also that they only last like 12 months whereis oem ones will last longer...anyone heard of nolathene's being destroyed after a year?

[Stain]

RCA's-roll centre adjusters. im not entirely sure how these work, but they go between the bottom of your strut (fronts where talking about) and the hub thing. they are designed to stop "bump steer". i have never experieced bump steer, but these are suposibly suposed to stop it[/b]

RCAs go between the bottom of the front struts and the lower control arms and are used to put steering/suspension geometry back into alignment on a lowered car.
It's hard to explain without diagrams, but if your planning on dumping your car then you need RCAs...
My only experience in bump steer was as a passenger in a S13 and it ended up riding a gutter and bending a rim after a rather enthusiastic encounter with a pothole.

[terryo]

anyone in brissy area can come to my shop and I can show you all these parts off my race sprinter and explain what they do. saturdays are best for talking.
coil-overs generally are deemed illegal cause they involve welding of a suspension member (the strut tube). The common practise of cutting and re-welding the strut tube (to shorten it) is dodgy to the least. we shorten them by cutting off the top and re-thread the tube in our big lathe.
Dont get too carried away with bushes or springs if its a daily driver. the back suspension especially needs to move to allow good handling. the top arms can be a real problem if you get the bushes too stiff, as they are too short to start with. many of the old racers used to deliberately leave out one top bush or make it squishy to allow the back to move just a little.

[LordNafe]

My understanding of RCA's is that they push the LCA down, thereofr pusing the steering arm and tie rod back down to be in line with the rack, therefore realigning steering and getting rid of bump steer? Am I correct?
And yes, ou can acheive jsut as good a set up with shock and spring rather than coilover, only thing si that you won't have height adjustability. You can still definately get adjsutable shocks without having to get coilovers.
When funds permit, I'll be getting terryo to build me a pair of front coilovers http://www.ae86drivingclub.com.au/forums/emoticons/smile.gif

[balistic]

Some good basic info here too:

http://www.technotoytuning.com/faq/

[turbo_rolla]

I've currently got pretty severe bumpsteer in my ke70 http://www.ae86drivingclub.com.au/forums/emoticons/dry.gif .....did not know wtf was causing it, but now do and know how to fix it! Will have a pair of RCA's from technotoytuning on the way shortly! Pretty hairy stuff, especially when you're going quick. From my experience, when i hit a bump cornering, it felt like the whole front end was gonna spit out the side of the car (mostly happened to me when cornering right, and felt like it was gonna spit out the LHS where the load was), and you can definately feel it through the steering wheel http://www.ae86drivingclub.com.au/forums/emoticons/blink.gif Not the best feeling when you're buzzing over uneven ground!

There's a good discussion on RCA's and bumpsteer in the following thread (towards the bottom):
Have a lookie - bumpsteer & RCA's (http://www.ae86drivingclub.com.au/forum/index.php?showtopic=755&hl=bump+steer)

Thanks for inadvertantly helping my solve my problem http://www.ae86drivingclub.com.au/forums/emoticons/2thumbs.gif

[terryo]

close...... on AE86 strut based suspensions, RCA's put both the steering arm and lower control arm angles back to where they should be after lowering. there are 2 problems with lowering
lowering always alters the angle of the lower control arm (also called the wishbone) & therefore moves the roll centre , which is an imaginary point around which the front/rear rolls. The height of the roll centre above the true centre of mass of the car determines the roll angle for any given cornering force.
Conversly, it is the anglular change of the steering arm that causes bump steer. what happens is as the car is lowered the steering arm moves from horizontal to upward. therefore, further upward movement from hitting a bump, shortens its effective length and pulls the wheel inwards ((in most cases). thus, the wheels move in and out as you hit bumps and the wheel falls back down.
Both are relatively simple trigonometric problems once you understand them.
No strut based suspension on a road car should be lowered at all, without making these corrections. The factory settings are almost always the best compromise, so put them back to where they should be.
Buying RCA's is just a guess. you really need to measure the problem and decide on the correct thickness

[ke70dave]

woah awsome explanation man!! thanks heaps, is an easy way to accurately get the correct rca length?

[HYPNTK]

goofball question but i gotta learn somehow...what the hell is a strut? i can never figure it out...some american websites call the shock a strut

[turbo_rolla]

the strut is effectively the casing that surrounds the actual shock absorber (long thin thing that your brakes connect to). that's the simple answer....someone else will give a more detailed one no doubt http://www.ae86drivingclub.com.au/forums/emoticons/2thumbs.gif

Quick example i pulled up off the monroe site:

http://www.monroe.com.au/images/Tenneco/marketing/Logos/QSLabelImage250wide.JPG

[HYPNTK]

aaaahhhhhhhh

[terryo]

if someone in brissy/ipswich area has an absolutley stock sprinter, I'll measure all the angles and work out the RCA's for you. my race car is lowered about 50mm and I have used 35mm thick RCA's.

[HYPNTK]

if someone in brissy/ipswich area has an absolutley stock sprinter, I'll measure all the angles and work out the RCA's for you. my race car is lowered about 50mm and I have used 35mm thick RCA's.[/b]

why couldn't you be in melbourne dude hehe

[damo101]

if someone in brissy/ipswich area has an absolutley stock sprinter, I'll measure all the angles and work out the RCA's for you. my race car is lowered about 50mm and I have used 35mm thick RCA's.[/b]

what happens if u got camber ?..ive just put in ra40 control arms and got -2 degrees out of it..but i havent lowered it yet..does that affect my roll center?

[terryo]

I recall ra40 arms are the same length as AE86 , and if so, I don't know how you got -2 degrees. lowering will increase camber and effect roll centre

[rthy]

ra40 is the same as the xt130 arms
RA60 are the same as ae86 tho


i wanted to get some cheap suspension in the ae86, but as i found out that wasnt to be...
for a little extra excel g's could have been bought but i was to lazy to drive 5mins...

Front:
Gabriel Ultra GT4 ST184 front shocks (130pair new)
Kmac Low springs cut down (2nd hand, lovells are 150pair)
T3 MR2 60mm spacer/gland nut (60usd pair new)
Whiteline RCA (20-35mm?, 220pair new)
some Alloy strutbrace (160 ajps)

Rear:
Gabriel Ultra Sierra front shocks (105pair new)
Kmac low springs cut down (2nd hand)
Whiteline adjustable Panhard rod (110 new)

http://www.technotoytuning.com/index2.php
http://www.whiteline.com.au/parts/default.asp
- Look under corolla
http://www.lovells.com.au/
http://www.kyb.com.au/
http://www.gabriel.com/
http://www.ajps.com.au/

WoWoWoWooooo G-Force! meh...
http://www.gabriel.com/gforce1/eng/default.htm

and yes, the springs are captive http://www.ae86drivingclub.com.au/forums/emoticons/ohmy.gif
[attachment=9286:attachment]

[HYPNTK]

its a wonder how you guys remember all the different bits off other cars that fit to sprinters