AE86 Aftermarket Suspension information & explanations

[assassin10000]

AE86 Aftermarket Suspension parts information & explanations. The basics on what they do, and how they work. I put it in my own words (laymen terms) as best as I could, so hopefully its easily understandable to everyone. So here's the short list, as I'm not going to be going into everything available or possible.


Feel free to post a correction if I'm wrong somewhere, or if you have something to add (more parts may be added to the list at a later date).

Enjoy,
Andrew

Also, just because you read some of the benefits of these parts here. Don't expect to be able to buy any of these parts and be able to instantly utilize the advantages they give you. That comes from seat time/experience, and to some degree talent. (IE: just because you have the parts, don't expect to be the next Alex Pfeiffer, Taka Aono or Keiichi Tsuchiya.)



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Tension Rods :

Because of a rod end which is a solid (non-complience) pivot point on most aftermarket tension rods you get a much more controlled front control arm 'arc' or movement. And also more importantly no excessive fore/aft (front/back) movement under braking, acceleration, turning and any other vehicle manuevers.

They will also allow you to adjust your caster much easier, and more precisely than factory bushings.

You will get much better turn-in (steering response), steering feedback through the steering wheel, and better braking feedback & response.



RCA (Roll Center Adjuster) :

Helps to correct roll center on lowered cars, by changing the lower control arm angle. This change affects how the suspension handles the forces exterted by the car. Resulting in a better handling car, due to better weight transfer characteristics.

Also, due to the AE86's suspension/steering design a RCA/NCRCA when it corrects the control arm angle, it also changes/corrects bump steer. As when it spaces down the control arm it also spaces down the steering knuckle and tierod end mounting point. So you end up with a smoother more controllable vehicle.




NCRCA (Negative Camber - Roll Center Adjuster) :

Adds more Negative Camber, by spacing the front struts outwards at the bottom (hence the NC in NCRCA).

Helps to correct roll center by changing the control arm angle (see above for more info).

Also, due to the AE86's suspension/steering design an NCRCA/RCA when it corrects the control arm angle, it also changes/corrects bump steer. As when it spaces down the control arm it also spaces down the steering knuckle and tierod end mounting point.

Because of its design, the NCRCA spaces the front struts out from the ball joint/pivot point. Which widens the front track, IE: the point of the contact patches the tires make. Wider usually equals more stable in turns, but just remember the rear hasn't been widened, so this change will affect the handling of the vehicle. It will provide better turn in and front grip throughout a turn, but you may have to change your setup or add spacers to the rear wheels to compensate, it would depend on your desired handling characteristics.

Changes your scrub radius. The track width increase occurs on &/or past the pivot point (IE: lower ball joint) so when you turn the wheel it rotates in a wider path around the pivot point. It will give you more 'feedback' through the steering wheel as the extra length provides extra leverage for road irregularities to feed back throuth the tierods/rack/column to your hands on the steering wheel. It also means that if you hit large bumps/potholes/debris/ect it will also fight your hands from holding the steering wheel a little bit more. But that isn't a big deal at all, just something you have to get used to.

Changes your SAI (steering angle inclination) which can be good or bad, but in this case it's good on the ae86 chassis when lowered (afaik, I'm not too up on my suspension geometry/theory/ect. So I'd recommend you do some research to really understand this) This makes the steering wheel feel a little lighter in your hands when turning (IIRC).



Camber Plates :

Fairly self explanatory, they replace the factory strut top mounts and provide a sliding adjustable mounting point that allows you to change the camber of the front wheels. On average you can get up to 2.5-3.5 degrees of camber from just camber plates, or you can correct out to 0 degrees on a lowered car if thats what you wish to do.

As a side note, you will probably only be able to get around 2.3-2.8 degrees of camber max with full size replacement lowering springs (IE: TRD race, Swift, KGMM, Eibach, Whiteline, ect). Because the full size spring & factory spring hats will come into contact with the strut tower before you are able to get adjustment beyond that point.



Sway bars/Sway bar links :

A.Simply said swaybars/stabilizar bars help keep the left & right suspension to compress or expand at similar times, to keep the car more flat when cornerning/drifting/lateral G's are applied. How well they do this, how fast it occurs, and how much motion it transfers from one side to the other is a product of: Different bar size (thickness), designs (solid or hollow & how many bends), materials, and the bushings/how its mounted all affect how each will work.

B. Swaybar links are a link between the control arm, axle or other suspension component which attatches it to the swaybar/stabilizer bar. They transfer the movement/motion of the susp/axle on one side of the vehicle to the swaybar, and then from there to the other side of the cars susp/axle.

Again, different materials/design affect them. And they in turn affect how well the swaybar/stabilizer will work depending on what material is used in the construction of the link. Rubber bushings on the stock links deform under load and that deformation translates into additional load needing to be applied to the links before the swaybar/stabilizer bar will even start to work. Polyurethane deforms less so and is a good upgrade. Going to a solid type of setup like rod ends/heim joints or even specially designed ball sockets will provide no flex and almost instant repsonse.



5-link (Rear control arms and lateral/panhard bar) :

Upgrading your bushings to TRD rubber or polyurethane with help eliminate excessive complience (unwanted play) in your rear suspension.

Going to an aftermarket 5-link which has delrin, polyurethane and/or rod ends further eliminates complience while also in many cases providing an adjustable link. On the 4-link you can use this adjustment to correct rear differential pinion angle. This also allows you to the wheel base (axle position, front/back) a little if you felt like it. On the lateral/panhard rod the adjustment allows you to correctly center your rear differential (or in alignment/racing terms set your thrust angle).

More in-depth info here: http://www.club4ag.com/faq%20and%20tech_...ersion.htm



Traction Brackets :

Installing these on lowered AE86's corrects the rear lower control arms (lower 4-link) geometry. What they do is change the angle the arm/link sits at, when it does that it allows the car to better apply a downward force on accel via the tires to the ground. Basically the suspension pushes against the car and forces the tire downwards, resulting in increased traction. It's something thats mostly noticed on acceleration.



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Much of this post/info has been better explained elsewhere, but it goes way more in-depth. Do some research if you want to know more about anything, or ask questions and I'll see if I can elaborate (or maybe someone else will chime in).

[assassin10000]

This post left blank, in-case 2nd post necessary to expand.

[banpei]

Added a link from the tech-faq:
http://www.aeu86.org/index/technical-faq...post=58122

[Jan Pedersen]

Another great write up by Andrew

[jondee86]

(a) I cut two coils off all my springs to slam my ride and make it
handle, but now it rides like a bullock cart and won't turn in under
brakes What gives

(b) Since I put 12/10 kg springs in my car for drifting, I can't get home
from the supermarket without the cream turning to butter !!! Are my
shocks in need of replacement ? Should I try low fat

© Now that I have changed my 13 x 5.5 rims out for 14 x 9.5 with
race rubber, I get a smell of burning in the car, and it is harder to turn
than a 1937 Mack truck. Do I need a power steer rack, or should I just
harden up

I'm sure you can think of more

Cheers... jondee86