Steve Weiner-Rennsport Systems

OMG, yes for lowered cars that are at RS height.

The steering geometry would be all wrong at US ride height, creating the same bump steer problem.

mhm993

Upgraded uprights is one of those mods that you don't realize how much you needed until after you do it. It's noticeable that the car isn't fighting you after the mod.
Much easier to crash curbs at the Glen, too.

OverBoosted28

I posted the pics as comparison, to show how the RS bits alleviate the "bumpsteer", that is a result of lowering beyond what the standard units were designed for. As Steve is pointing out, if your car is at standard US height, putting these parts in would likely create a "bumpsteer" affect. From what I researched, and if my understanding is correct. You want the tie-rods to pretty much be parallel with the control arms. If your car is not lowered that much, you most likely wouldn't gain much from these bits.

chaoscreature

Do the RS uprights also lower the car? In pictures it looks like the spindle bearings are mounted higher on the RS uprights vs the stockers. This is a mod I badly want... at RS+10 I get a decent amount of bump-steer.

Steve Weiner-Rennsport Systems

These have no effect on ride height; just steering geometry.

13BEEZ

Is there a specific range (mainly looking for a maximum height) where the RS uprights start to create issues. For example, from what i have read, at RS +10 and below, you will eliminate bump steer with RS uprights. However, if someone was running somewhere between RS and ROW sport, would that be too high for RS uprights? Or is it not until you start to approach US ride height that the RS uprights would have an adverse effect?

Bill Verburg

Bumpsteer can never be eliminated, only minimized.

The RS wheel carriers and outer tie rod ends work best from RS down to Cup/RSR ride heights(134/117 to 95/93mm), the further above that the worse the induced bumpsteer will be.

The standard wheel carriers work best at RoW ride height(164/157 to 134/117mm), the further above and blow that the worse the induced bump steer.

You'll note that the top of RS is the bottom of standard.

Bump can be further optimized by using o/s tie rod ends and actully 'bumping' the suspension

ThomasC2

I did this upgrade on my 964 track car last winter so this summer was the first season driving with the 993 uprights. It's a little more work involved doing this on a 964m but I'm really happy with the result. The front end behaves so much better than before.

Thomas

Cupcar

Probably, going the other way though.

Nice pictures.

Cupcar

If you kept the lower control arm angle the same in an experiment between a car with and without, the RS hubs would lower the car by 30 mm.

What they really do is allow a better angle of the lower control arm at a low height.

13BEEZ

Thank you! Exactly what I was wondering.