swftiii

All,

I did try to search, but didn't find anything.

I have the PSS9s and RS Sways on my C4S and was making adjustments to the front sway bar today. I understand that I cannot use the stiffest setting because of the AWD system up front. I set it to the Second to stiffest setting and when the car is jacked up the Drop Link is resting on the control arm - IS THIS AN ISSUE?

Thanks,

-Skip

Mark in Baltimore

Yes, Skip, it's a most serious issue that would best be solved by going back to your much safer stock bars.

Very bad indeed.

swftiii

Thanks for the sarcasm and help today with the DAS bar install. I just want to be sure it isn't an issue.

Later MinB.

Skip

Tom W

You already have your rear at stiff and you need more stiffness up front? I'm mildly surprised that the C4 has that much more understeer. (I was always told to use the rear as the coarse adjustment and the front as fine adjustment - and my cab does great with the rear on firm and the front in the middle.)

swftiii

Tom,

The plan is to set the PSS9s to 2/1 (Front/Rear) and the RS bars to as stiff as possible (1 less than full stiff on the AWD cars) in the front and middle in the rear. I believe this will reduce some of the standard understeer, but avoid too much oversteer. It is just a starting point and then I'll adjust based on track time.

I thought, maybe incorrectly, that to reduce understeer the rear should be set less stiff and/or the front set more stiff.

Let me know if I'm going about this wrong.

-Skip

Mark in Baltimore

Skip,

Have you seen this Rennsport Systems Handling Guide? I have my bars set at 1 front/2 rear to add a bit of understeer and stability to the car, but, according to Steve W's guide, this set up is not the way to achieve more oversteer. For more oversteer, you would want to set the front bars to a softer setting than the rears.

Did I tell you the wrong settings today?

swftiii

Mark - thanks for the link and yes I have read it and think I had remembered it wrong. Guess I need to go the other direction as my car already has a good amount of understeer. As for the PSS9s settings, I must have heard you wrong.

Tom - sounds like you were right on and I was not thinking correctly.

So let me start again: I'll set the PSS9s to 2/2 (f/r). Now, I'll move the front sway bar back to the middle and stiffen up the rear sway bar. During track time, I'll adjust the shock dampening based on driving characteristics. I hope to maintain a little understeer, but not as much as exists in the car today.

Thanks Guys,

Skip

Tom W

Skip,

Like I know what I'm doing? (I wish) I just set like I was told by Steve W or viperbob and it worked very well. I set my PSS-9's to 2/1 f/r (at 1/1 the front bounced too much on the berms) and have my Rs-bars set at mid/firm (f/r). I was very happy with it.

Now I have to start all over on the bars as I have a differnet car! (Which is set-up pretty well to start, but needs to be driven more so I can see what to do next.)

Steve Weiner-Rennsport Systems

Hi Tom;

LOL,..I can surely help with getting your track car setup properly,... (psssst,...Moton Clubsports with a custom dual spring package and ERP rear spring plates)


Skip:

I'd set those PSS-9's to 3 front and 1 rear for track use. This helps with understeer as 1 is too stiff for the front tires to bite.

You want the front end to transfer weight more than the rear to get the car's handling more neutral. Set the front bar in the middle hole and tighten the rear,....

If you want to dial out the understeer, set the front bar loose and use the 20mm GT-2 rear bar...

swftiii

Thanks Steve - I'll give it a shot and see where it takes me.

-Skip

DJF1

SKip, I would recommend you start with the setting Steve told on on the PSS-9, but start with both bars middle stiff. Get out do a few laps and see what the car is doing. Then work the front end accordingly. Meaning if the car understeers which it might then move the front bar one hole looser. Get out and see what it does again. If still more understeer move the front sway to full soft and repeat. Bear in mind that the car will not behave exactly the same on all turns. In other words if you have understeer on a tight turn you might not have understeer on a fast one. In other words see the performance as a whole package in a lap not an individual corner. Also take into account which corners are the most important on a specific track and make sure that on these corners you have a very nicely balanced car so you can get the best exit speed.
To this day I have not gone full stiff on the rear bar. Bear in mind that stiffer is not always better. A bumpy race track can slow you down if you are too stiff. Also stiffening to the max the rear end on an oversteer situation the oversteer will be a bit more hard to catch as it is going to occur faster and less progressively...
One very nice shock tuning guide ( thanks Greg) is found at www.penskeshocks.com While this guide applies to 2 and 3 way adjustable shocks it gives you a good idea on setups and how things work..

Good luck Skip!

FlyYellow

skip - fyi.

i have my rs bars set to max stiff in the rear and second loosest in front. I think the car is fastest that way - but you can certainly bring the rear around when you want to. disclaimer: it probably is not the safest that way for street driving.

Cheers,
Boris

swftiii

Thanks everyone you have all given me something to think about and play with. I'm excited about the setup and look forward to getting to the track soon.

-Skip

JohnM

Skip,

What tyres do you have?

On a C4 with 225/285 my experience with RS bar settings is:

F middle/R middle: understeers, have to wait forever to get on the throttle in the slow corners.

F full soft/R middle: only understeers a little on entry to fast corners (not necessarily a bad thing ) and can get on the throttle much, much earlier in the slow corners. Downside is at RS height a sort of bump-steer effect on entry as the front rolls too much (for my liking anyway), but if your car is currently as the pic in your avatar you are well above RS height so this would not be a problem.

F middle/R hard: understeers, not as much as middle/middle but much more than soft/middle. I'll be trying this setup again but with with 245/285 once the weather improves, if it still understeers then the front will get set one off full soft.

Hope that helps, but of course driving style etc makes quite a difference as well. As someone else (I forget who) observed a while back, what felt nicely balanced when you start doing track sessions comes to feel like it understeers beyond belief as the track days and miles accumulate.

swftiii

Thanks John - I run MPSCs in 225/285 (f/r). I'll play with the settings at the track and see how the car drives. Not exactly sure what to expect, but looking forward to the track time.

-Skip