SmokeyGatto

does it add caster in the sense the lower control arm is pushed out, no, but perhaps by offsetting the way the knuckle sits it has some change.

gtracer

Fair enough. I wouldnt want to start palying with Caster using that method however..

Goodballa

I know this is an old thread, but can someone explain to me how this works? Sorry for such noob question, I've been trying to find definitive answers to these questions for quite a while. I can't quite get my head around it yet due to this question, that I don't think is possible. --> Could you use upper and lower (roll center adjusters) camber adjusters and pull the bottom and the top of the wheel in in order to install wider wheels? I don't see how this would be possible. If you pull the bottom of the tire out does the top of the tire go in? Is everything somewhat hinged on the hub in the suspension? The reason why I ask is because I Bought some 17x9.5 +51 Titan 7's and they stick out more than I would like/thought they would. I am wondering what my best hope is of getting them closer to flush. Will I need an upper camber adjuster, and possible roll center adjusters to accomplish what I need? Also, will I need any caster or toe adjusters if I go 2" lower? I will most likely be lowering 1-2" with around -3 degree camber front and rear. I'd like to have it set up for street and track with priority given to the track. Please enlighten me S2ki'ers.

Mugen_is_best

From what I understand, a roll-center adjuster aka ball joint is the best fix. I was in this same boat not long ago after moving to a square wheel/tire setup. At first I only installed the front RCA, but the rear of the car exhibited too much roll for my liking. After installing the rear RCA everything was gravy again. I'd suggest doing an RCA>SPC upper joints or UCA offset bushings.

DavidNJ

There seems to be a bit of an apples and oranges discussion here.

When the car is lowered, the control arms adapt an unattractive geometry with the lower arm pivot lower and the upper arm at a more severe angle. That typically reduces the swing arm radius and raises the roll center. It also causes the roll center to change more dramatically in response to bumps.

It also causes a reduction in bump and an increase in droop on the shock.

The real fix is a dropped spindle that increases the distance from the axle to the lower balljoint and decreases it to the upper balljoint, maintaining geometry and stock travel. A quick google will show dropped spindles available for quite a few applications. Unfortunately, the only choices for the S2000 seem to be the WIsefab suspension kit and some semi-custom machined aluminum ones. In either case, fairly expensive.

The roll center adjuster takes advantage of the way the lower balljoint is connected to the S2000 spindle to increase the distance from the balljoint to the axle. There is now way to lower the upper balljoint. Some of the RCAs also increase camber by moving the balljoint mounting laterally in addition to vertically.

The top camber adjustment plate increases the camber by moving the upper balljoint mounting inward (the balljoint outward relative to the spindle These may also allow an easier and more accurate camber adjustment, especially at the track. Increasing the negative camber frequently allows wider tires to clear the front fenders. On the street, the OEM max -1.7° to -1.9° is probably more than enough. On a race track, over -3° is probably the minimum, especially in front, requiring either a kit on the upper or lower balljoint.

The closest to a real solution is the Wisefab kit which includes new fabricated suspension links with spherical bearings and dropped spindles. It lowers the car 40mm (quite a bit) while maintaining geometry. It also allows quick camber adjustment. I believe it raises the steering arm on the spindle minimizing bump steer changes.

WIsefabs kits are widely used in drifting on Nissans and Supras. They have track kits for the S2000, Evo 7/8/9, Toyota FT86/Subaru BRZ, Nissan GT-R...good company. However, other than the approximately $6000 cost it would be illegal in many racing classes. Evasive is a US dealer. https://usa.wisefab.com/

Mugen_is_best

Apples vs oranges vs bar of gold

robrob

In the s2k caster and camber are adjusted by moving the lower control arm--they are tied together and interact during adjustment. The SPC camber ball joints change this in two ways: You no longer have to give up caster to get maximum camber and by angling the SPC slot to the rear you can add caster. Caster is controlled by the rearward lean of the steering pivot. Add more rearward lean and you add more caster. If you don't understand this you don't understand caster and how it's generated.

Typically though just adding camber with the SPC ball joints will allow you to get all the caster you need with the stock caster adjuster.

s2000Junky

How about angling the slot on an upper joint in the rear upper control arm forward to favor more toe 'in' for the sake of then increasing the length of an aftermarket adjustable toe arm to re compensate, removing further toe/bump? Ever examine/consider this? Shorter toe arm means more toe movement under wheel travel right? So do whatever to adjust the control arm pivot to favor a longer length adjustment on the toe arm. Running a rear rca which addresses the lower control arm is separate from the tow arm angle, so looking for ways to further remove bump steer beyond what the typical drop link spacers provided can compensate for. I think this could only work possibly if you are favoring more positive rear camber adjustment, which when lowered is the more typical for the rear anyway, unlike the front. Or maybe it doesn't matter, have to think about that more. Just going off memory how the rear wheel pivots without the upper control arm unattached, but might be totally universal so could be set to do same thing with adding or subtracting camber depending on what you want more of. Tracking with me?

noodels

Interesting topic,to add >
am lower with Ohlins 25mm+/- fronts,bit more rear for correction,=0 rake
and now of a maxed out caster,feels really great though,<thanks to peeps on this forum> its non track car.<see below>
4-6 caster being an ok config for an S2000.
Q:do I really need SPC ?
& will it drive better with the balanced caster & will I notice ?
Doubt it