PSS9 Rear Spring Alternatives

[rsrmike]

Hello,

I need help/info about raising the rear spring rates on an RS America converted to RUF RCT specs.

It belongs to a good friend who has offered to let me track it with him. We've already pulled the original RUF suspension and stored it away. He found it way too soft for his taste. (he's a nut when it comes to suspension).

I installed a PSS9 system he had lying around from his other RS america. It was better but now it feels the rear spring rates are too soft. With the added weight of the turbo and it's extremely heavy mounting components, not to mention the 400+lbs of torque, it just seems to overwhelm the rear springs.

He ultimately would like to install a complete JIC suspension, but I mentioned perhaps we could just raise the rear spring rates and improve the car without going to extremes...

here are my questions:

Does anyone know the rear spring rates on a 964 PSS9 setup?

What is the spring diameter? (it's currently assembled and at his house so I would like to know what to order before I go get it and tear it down)

I'm guessing I can order some standard 2.5 race springs and pull the PSS9 springs alng with the "helper?" springs and adequately stiffen the rear end to his liking?

Does anyone have experience with this they are willing to share?
Thanks in advance!!

[rsrmike]

Bueller?

Any recomendations on a good source to order an assortment of springs?

How about spring rate ideas? We want it STIFF...

[Don Plumley]

Here's a thread with some interesting data - but it is for a 993, and not a turbo.

[Bill Verburg]

Thiis is what I have listed for PSS9 used on a 993
225-250 fr 400-685 rr

[rsrmike]

Thanks guys, that give some insight

I realize I have a bit of a bastard on my hands, and a need to learn more about suspension prep...

Can you recommend any good books or online tech articles that are more recent and relative to today's suspension and tire technology?

[Big Bob]

From what I understand, your friend ought to bite the bullet and spring (yes, spring) for the JIC. The Pss9 is just old news, and I've not heard of anyone who -- once experiecing the JIC set-up -- would want the Pss9.

[rsrmike]

Originally Posted by Big Bob

From what I understand, your friend ought to bite the bullet and spring (yes, spring) for the JIC. The Pss9 is just old news, and I've not heard of anyone who -- once experiecing the JIC set-up -- would want the Pss9.

That's probably what will happen, I guess I'm being conservative
What can I say, I'm a Bilstein fan...

Thanks,
Mike

[Big Bob]

I'd love to hear of anyone who favors the Pss9 over the JIC...

[Bill Verburg]

The current Bilstein multi adjustable offering is PSS-10, for mostly street use that would be the way to go, but even that is way beyond what most people would actually use. Bilstein HD w/ your choice of springs from H&R or Eibach or even the RoW M030 would be fine. Most people never use the adjustment features. I never looked into it but maybe even the JIC springs could be used.

So far my issues w/ JIC have been issues getting the proper rear drop link mounts, issues w/ camber changes, lack of responsiveness from JIC re either of those issues.

[rsrmike]

Thanks Bill! It's good to hear REAL technical feedback versus fanfare. It's funny how quickly people curse something as nice as a pss9 when something newer comes out. Suddenly the old news is JUNK. I would rather up the spring rates and use what we already have, versus spending several thousand $$ to join the "fluff" Don't get me wrong, JIC isn't out of the question, but I would much rather have Bilstein, even more so now after the technical issues you just mentioned. I haven't even called Bilstein yet, I probably should. Although I don't think they sell springs...

Might I ask what is a good spring rate combination for a

[Bill Verburg]

spring rate and ride height ar decisions that need to be made locally
here are some that are typically used
US factory M030 150-200 fr 225-275 rr
Eibach 7209 120 fr 200 rr
Weltmeister 180 fr 268 rr
H&R peformance 240-260 fr 280-310 rr
H&R coilovers 290-310 fr 350-370 rr
H&R supercup 310-350 fr 385-435 rr
BIlstein PSS-9 225-250 fr 400-685 rr
"Motorsport" 600 fr 800 rr
JIC 392/560
JIC 448/672

[GG Allin]

A Ruf RCT spec RSA? Post pics. please.

[rsrmike]

Bill, thanks very much for the info, that helps put things in perspective.


It was really more of a highway car for the P.O., but I'm trying to make it suit the new owner a little better, plus he wants me to share it on track days!! (although I'm reluctant as I couldn't afford to fix it if I wrecked it)

It's really a neat car, I'm honored to be it's caretaker. I just want to serve it well.

[Bill Verburg]

Dr. Bob White is a legend, and that car is awesome! Do keep us informed as to your progress.

[rsrmike]

I certainly will, thank you for your help.

I don't know the Professor, but would hate to upset him with the molestion of his creation. Every change we make will be reversible and each part safely stored away, so it can be returned to it's original state, should the need arise.

It may never be a great track car due to it's weight, but it is truly a beast on the street! The custom gearing in the 6 speed conversion is just incredible. Every gear gets better and better.

The new owner is not entirely technical, but he is very passionate about the way the car feels and responds to his input. He's also a good friend so I really want to help him enjoy the ride.

Thanks again,
Mike

[AFM744]

Originally Posted by Bill Verburg

spring rate and ride height ar decisions that need to be made locally
here are some that are typically used
US factory M030 150-200 fr 225-275 rr
Eibach 7209 120 fr 200 rr
Weltmeister 180 fr 268 rr
H&R peformance 240-260 fr 280-310 rr
H&R coilovers 290-310 fr 350-370 rr
H&R supercup 310-350 fr 385-435 rr
BIlstein PSS-9 225-250 fr 400-685 rr
"Motorsport" 600 fr 800 rr
JIC 392/560
JIC 448/672

Whoa. That would explain why I think my Eibachs are too soft (especially for a Turbo). Car squats like a 280Z.