Serge944

Only difference is that the firehawk rear shocks are merely shocks, requiring torsion bars, while the escort are coilovers.

Robby

Actually, the REAL dif is in the valving- otherwise, yes, the rears.... I don't want rear springs whether helpers or coil-overs, so.... Escorts would not be worth the extra $200.... but, the valving is more than half again that of Firehawks.... look at the #'s... Now, the one thing I do not know is, what the actual rates are hat are supposed to be used w/those #'s... I only know what I've been told... Many people have used the Escorts on these cars, but, most have said they were fairly stiff....

Mark Lue

Quite an interesting thread we have going on here. Many different points of views and no one getting carried away.

May be the blurb below may help those budget minded souls among us

Living in the area of Canada where the Rothmans Porsche Cup Series was held, over the years I have had the opportunity to speak with several of the chief mechanics of the teams that took part in the series. Many of them are active members of our PCA Upper Canada Region who still operate successfull Porsche Service Centers. The Cup cars were limited by the series rules and the same Porsche suspension parts were available to every team, so apart from the driver the advantage was in the suspension alignment/adjustments and the 944 is VERY adjustable. In a nut shell what they tried to achieve was a car that "rotated" in corners with as little slipping of the rear wheels as possible. Key adjustments were to the rear ride heights and the toe settings. It was even mentioned that they would even soften the rear sway bar. Not much more details were given and the cars are race cars after all but food for thought nevertheless, eh !

I asked 2 of them about aligning my NA for DE and the answer was to start with the factory alignment specs and learn to drive the car with the best tires I could afford.

Nough said.

Robby

Mark- what would you do to help the car rotate while still keeping the rear tires from slipping first?

I remember Lindsey Racing had Turbo S or 968M030 sways on their project car at one time- their write-up said that they ended up going back to slightly softer sways b/c the car was actually so much lighter & stiffer, etc, that the sways were boxing in the susp too much & weren't allowing the independent susp to do it's job....

joseph mitro

i'm certainly not an expert, but my alignment settings are as follows:

front: -2.7camber, 1/16 toe out, 0 caster
rear: -2.0 camber, 1/16 toe out

i THINK that the toe out in the rear will help the car rotate, and the negative camber keeps the tires planted. someone correct me if i'm wrong.

M758

I have been out and missed alot of this discussion, but will add in my experience.

Firstly

my 944-spec set-up, 350lbs front springs with 30 mm tbars. Welt sways and Koni yellows.

Per rules I am limited to Koni yellows (or bilsteins) and a max of 30 mm rear t-bar. Also per rules car min weight WITH driver is 2600. So car empty is 2450 or so. Figure 300 to 400 lbs ligther than stock. That reduce weight really translantes into more stiffness that a car at stock weight.

over the years the suspension inthe car has evolved.

Started out with stock suspension (even old shocks) and stripped out interior. Car was well balanced and quick. It is roll a bit, but was still fun.

I later installed 250 lbs springs. Well the car did not roll as much, but did have LOTS of understeer at the limit. Given my limited skills when I started it make the car faster, but I did have to constant flight understeer. I then moved to weltsways and 28 mm t-bars and the Balance returned. I got faster and so did the car. With this set-up the car was stiff, but body roll was controlled and it reacted quickly. Later I installed fresh Koni's and 350 lbs front springs. The understeer returned. I could dial it out by cranking my rear sway bar full stiff, but it was not ideal and limited me else where. Eventually I got 30 mm t-bars in the car and balance came back. I softened the rear sway bar and fiddled with the front till I got a very nice balacne. It has probably more oversteer than most would like, but given my increased skill level it worked very well.

Later on I got a an 83 944 NA for parts and autocross use. Well I learned that even 100% stock old worn out form the car was well balanced. Sure it pitched and rolled ALOT, but the balance was there. Later I put in fresh KYB's because I did not want to spend the $$$ for Koni's. Again the balance was there, and the car still rolled alot, but it was more controlled.

Well given little bit more skills I was able to hustle that stock street tired old 944 to some very fast ax times. Fast street tire or top 5 street tire times. I could do this since the car was balanced. I had to learn to deal with the body roll and slow reaction, but as long as I could get the car to rotate I could make it fast and it would be fun. I considered increasing the spring rate on the car, but did not want to do t-bars so I left it stock. I knew it would be more fun and ultimaltly faster if it were balanced vs stiffer with understeer.

So for a dual use street /track car balance is what you want. Stiffer springs mean less roll and therefore better camber in the corners and also a faster reaction to input.

Now my 944-spec car I consider too stiff to drive on the street. I could do it, but it is no fun. I also consider it to be a "sofly sprung race car". This means it still rolls in the turns at bit. Now I can feel this going through turns at fast pace. Slow down a 5-10 MPH at it feels rock solid.

So what does this mean for street car. Well 350lbs /30 mm t-bars in a 2450 lbs car are too stiff and ok at the track. Going stiffer not reasonable on the street. For full weight car you MIGHT be able to get away with 350/30 combo, but it will still roll quite a bit on the track. It will however feel like a night and day difference between stock. Now just because the stock suspension has alot of roll does not mean it is bad. If it is balanced you can still drive quite fast even with the body roll.

So in a full weight car 250/28 mm t-bars make a nice stiffer combo. Stiffer on the road, but probably not so stiff as to be harsh. When on the track it will be nice "upgrade" from stock, but will still be rather soft.

M758

Oh...
... Also as you make a car stiffer I may become harder to drive. The reason is that it reacts faster to your inputs and you must stay ahead of the car. I have seen it where guys in 944-spec car jump from a street stock car to fully prepped 944-spec. They come back after a few laps scared since the car feel like its not sticking at all and given them no feedback. Usally soften the sway bars to full soft gives the driver enough feel to be able to respond to the car. Over time they can stiffen the bars as they learn to deal a "stiff" racecar.

J Chen

Hi M758,
Can you give me a recommendation ?
Right now I'm running stock sway bars f & R
with Leda coilovers with 300 F & 400 lbs R
without T bars. Car is mainly street driven.
I find that it's rather harsh. I'm looking for
good ride & neutral handling with stock
sway bars. My original intentions were to
change to 250F & 350 lbs R but am unsure
how it would turn out.

Thanks

M758

I don't have much experience with rear coilovers. From What I know it seems like the rear spring rate is softer. Rear is abou 260 lbs-in (assuming .65 effectivity). The front is stiffer however.

So 300 lbs front with 260 lbs-in rear at like 28 mm t-bar at 254 lbs in.

I figure you might be fine with 250lbs front springs and keep the 400 rear. Then again with Leda I believe you can adjust the shocks and you may need to soften them up take out the harshness.

Is this for a 951 or 944 and what tires sizes? What tire pressures are you running?

J Chen

Hi M758,
It's a 951. I'm running 17inch rims with
225F & 255R. Tire pressure I normally
use is 32-34 psi cold. I thought of going
softer for the rears as well cause I still
feel it's too harsh. Do you think if I keep
to the same percentage as the stock F & R
set up, I would still be able to achieve a
neutral balance ?

Robby

thanks joseph.... sounds like a decent thought to me...

Serge944

A respected rennlister, Tony G, ran 250# front with 450# coilovers w/o torsion bars and it was quite a good street/track car.

Im probably going to go 250# weltmeisters in front, 27mm sway-a-way torsion bars in the rear, and bilstein HDs over summer. Maybe even some S-03's if Matt H can hook me up.

Robby

Yeah, I forgot about Tony- that's equal to ~292lbs (@ .65), which is like having 29's in back... wow! Not sure how he runs his sways to deal w/that- he used Welts, i know that... He ALSO had Bilstein Escorts- he said he liked them, but, in all honesty, based on all the conversations I've had w/other Bilstein people, the Escorts are valved to go w/springs at least 50% stiffer than this- Firehawks were much more closely matched to his rates- actually, most people tell me that 250's are a hair soft for Firehawks, but, that they'll work, so..... But, tony said it felt great- wish I were on the west coast & I might be able to drive a few of these cars & see for myself..... As for balance, I'm not sure how that really felt, like I said- could have had rear sway set to soft, but, I also know that Tony is a pretty good driver- he runs WSIR a little bit, but, I don't know of any of his times.... I just assume, that w/his experience, he might e able to deal w/oversteer a little better than most, so, that might have worked better for him- I personally would not give the rears that much in proportion to the fronts..... but that;s just me....

Serge944

When you consider driving style, swaybars, and staggered tires, it all adds up. He said he was eating vettes for lunch on the track.

luckett

F/R camber settings also affect the balance. And different tires like different camber. Do you know what width/brand of tires and alignment settings he was running?