mikew968

Come to a race and see what the top finishers are running. There will be some difference based on what the car weights and what shocks you are running. At the limit the car (in my case a 968) wants to understeer so we are running a lot more rear spring. I am just under 1000f and over 1000 r. That is with DA Motons and milled down TB.

Mike

xsboost90

im running 450lb front hypercoils on a paragon products slide-on coilover setup w/ koni adjutables. Rears are 3012s w/ 525lb hypercoils and no torsions. MO30 968 bars w/ rears set to full soft and i run 16x8's all around on toyos and the car does really well. More rear tire would help though. 245/45/16

Van

This isn't 100% accurate...

Chad, read this thread: https://rennlist.com/forums/944-turbo-and-turbo-s-forum/360494-poll-spring-rates-w-torsion-bar-delete-bonus-track-pics-enclosed.html
It has lots of good data and it debunks a few "myths".

951and944S

Possibly....., the hard definitive numbers remain debatable, and hats off to you Van for the amount of effort you put into that long original discussion -

but the point I was making, (evident by the post I copied and replied to) was that a "50/50 weight distribution" of a 944 is not the sole factor in choosing spring rates to balance a 944.

T

333pg333

It also depends on the shock valvings. How they dissipate compression load v's not much at all for some more basic type models. I think if you are driving the car 90% on the street, you don't want to go any higher than 500, if that. I've got 616lb/in f and 708lb/in effective with t-b and very good KW suspension, but it's not a setup that I enjoy over crappy roads. It's better than some other cars that I've been in with lower spring rates though.

ausgeflippt951

Thanks, you beat me to it.

The amount a spring compresses isn't the full extent of it; yes there's shock valving, roll stiffness (front and rear -- not just the chassis as a whole), tire width and respective rates, and the individual suspension geometries to consider as well. Under load, the semi-trailing arm yields a completely different geometry (caster, toe, camber) than the MacStruts up front.

What I find surprising is that many don't consider the car's suspension as a package. How the wheels translate through the suspension, into the chassis is what's really important. Consequently, IMHO explaining what spring rates to run without suggesting tire sizes is completely worthless.



There truly is more than one way to skin a cat -- one guy may run a crazy rate difference (F:R) of a few hundred pounds. As a result, he may run a ton of bar up front and huge tires in the rear. The car may feel solid because of all the "compensations" he's made for the weird spring setup. But, the car doesn't need that. Running closer spring rates all the way around is the way the car was designed. Then, tailor your handling by adjusting bump/rebound, bar, and then tire sizes. This method seems to work best, IMHO.

M758

Chad,
My 944 spec car runs 350lbs fronts and 30 mm rear t-bars. I use Koni yellows all the way around and since my car is 2600lbs with driver these spring rates work quite well. Now clearly you can go much stiffer and some would say you need to get more speed. Maybe so, but if you are justing doing DE and want to spend less cash a 944 spec type suspension will work out rather well. I know you have stripped the weight so that will help. Once you get past 30 mm t-bars (330lbs effective wheel rate) and 400 lbs front springs off the shelf Koni's won't handle the spring rate any more. Thus you will be forced into more money for shocks. That is fine if it is what you want, but it is something to consider.

Mahler9th

This all seems interesting...

I don't think the internet is the best place for set up advice...

Anyway, I suggest:

1. Base your decisions on the tracks you intend to run. And the type of driving/racing you want to do. And whether further developments are planned, especially as pertaining to weight.

2. Seek the best pro advice you can get. I was down this road a lot between 1993 and y2k. I got advice from folks like the guys at KMR and Jon Milledge, as well as other pros that had Firehawk experience. These cars have been around for a long time... well before most internet experts began to talk about them on-line.

3. Don't forget to match springs and valving, sway bars, et etera.

4. I always liked many of the Racer's Edge products, and might consult with them for set up advice if they had experience with cars in my geo. area.

- Mike

4.

smlporsche

Chad-
I ran into alot of this when I was setting up my car (an S2 also). In addition to all this advise I would suggsest you call Karl Poetl at Racers Edge. Karl not only sells everything you'll need but as many here can attest he had THE fastest S2 in the country and won many races with it.

Having said that here's what I did based on Karl's advise:

Initially I set up the car on Leda coilovers with 450# springs all around (with the torsion bar removed). This was barely streetable and I would suggest you think long and hard about gong stiffer and driving it on the street.

Subsequently, I talked to Karl again as my skills improved and mimicked his car's spring rate BUT adjusted it to the lighter weight of my car. I'm now running 575# all around and feel that it handles very well.

I agree with a previous poster about running similar width tires all around to start (245's in my case). I'm now considering running a slightly wider tire in the rear as I'm learning to steer the car with my right foot

BTW I have a pair of 450# springs lying around if you're interested.

MTosi

Just personal uninformed opinion, but alot of people tend to run cars wayyyyyy to stiff. Once the front of the car becomes overly stiff it just plows. I remember standing on the inside of big bend during a PCA race a few years ago, watching all the people who talked about their 600-700+ springs (in various front engine Porsche's) and how great they are, go through with a constant state of understeer (pretty sure they were oblivious to it). It may be comfortable, but it isn't fast. I think it's in the book "Tune to win" where Caroll Smith addresses spring rates in production cars and how spring rates up around a 1000lbs are in his words "ridiculous".

TedA

If you are going to on the street at all, 400# fronts with 30mm rear TBs with Koni adjustables would likely be an economical and functional choice. Don't forget the camber.....

ausgeflippt951

Carroll Smith was a genius. Motorsports will miss him.

And MTosi, you've outdone yourself this time around with that avitar of yours.

Here's the full version of it, in case you weren't aware:



Another favorite of mine:












Ok ok ok, back to the regularly scheduled programming. I'm sure you guys don't mind tho, right?

951and944S

"Beat you" to what....?
Saying that a post that uses the terms "roughly" and "in my opinion" is "inaccurate"....?
Please.....,
Maybe you missed this post from the thread Van linked to clarify the accuracy -
"944 turbo cup cars had progressive springs rated @ wheel F 200-355 lb-in & R 320-545 lb-in.

H&R uses in their Clubsport-kit ( RSS-37-827-1/1 ) wheel rates of F 370 lb-in & R 555 lb-in. http://www.h-r.com/katalog_download_de/Porsche.pdf

Wheel rates counted from spring rates with multiplyers of F 0.9 & R 0.56."




Really.....?......the way it was designed, I assume you mean by the car manufacturer...?
Look up the front spring rate listed for a 944 turbo that were coupled with 28mm rear t-bars and post your findings here.

T

951and944S

Yep....., and to the best of my recollection, Karl himself posted here verifying both the Porsche R&D Cup Car F/R ratio figures and the .94/.56 numbers....or there-about on the rear.

I know the S2 you speak of if you mean the metallic blue one he sold about a year ago, a member of my region bought it from Karl and is the current owner.

T

Chads996

Good stuff Eddie. Thank you.

I have a good amount of seat time in various cars. The latest being my old 996. After having a number of M3's, I remembered how much I enjoyed the balance of these cars. Remembering my old 944T was much the same, I picked the S2.

With that said, I too like to steer the car with my right foot. Leda is not my preferred choice, but could end up being the direction I go as I have a friend who is tired of his setup. I am hoping to nab those.

At the moment, I have a staggered setup for wheels. No choice due to budget to swap. My long term plan is for a set of CCW 18's with equal sizing all the way around.

Thanks for all the info folks. Gave me some good thoughts and ideas.

C.