944 HPDE/TT set-up question

[speedshopjones]

I'm just getting started in NASA (but not HP driving) and my goal is to get to 944 Spec...eventually. In the mean time, I will be entering HPDE and TT with the 944. It is currently bone stock, but will be getting frt coil-over kit, 30mm rear torsion bars, frt & rr sway bar upgrades, etc. While it is an HPDE/TT car, it will still be a semi-dd. I'm curious about suggestions for front spring rates. I have read so many different opinions online, I'm dizzy.

 

I know once in Spec, most cars seem to run 350# - 400# springs. That would be a bit much for street use. So, I'm looking for a happy medium until then. BTW, I think I read that those upgrades will add so many points to the classification that my 944 won't be competitive in TT. However, my goal is to compete against myself and improve my skills as I slowly prep the car for Spec. (oh, Tires will be RA1s)

 

Thanks for any help. My first event will be in Pueblo, CO on April 14-15.

[Sterling Doc]

Welcome!

 

Lots of great racing in the RM region of 944 Spec.

 

My advice would be to leave the torsion bars & springs stock if you are going to be driving it on the street a lot. If you're only driving it a little, than put the full Spec suspension in.

 

30mm torsion bars have an effective spring rate around 350lbs/inch. Mixing 350lb rear spring rate with a 200-250lb/in streetable front spring rate will leave you with a very tail-happy, unbalanced car.

 

Put the Konis in either way.

 

I did HPDE in a 924S with stock springs, and Koni's for a year - it worked pretty well.

[speedshopjones]

Thanks! You're right about the balance. I've never messed with torsion bar suspensions. I do need to get it lower, though. Looks like it's on stilts at factory ride height. The springs and bars aren't too pricey, so I might match up a set of 250lbs/in for HPDE/TT. I don't have to drive it on the street. I just like to. A lot.

 

On another note, the guy that had always aligned my drag cars to perfection looked at me like I asked the square root of infinity when I asked about the best alignment specs for the 944 on the road course. Drag cars like a lot of caster, but that would have it always trying to pull you out of the turn(?), can't cross-caster or stagger since you turn both directions, but too little and it'll wander... positive camber to put max footprint in the turns? Hmmm. When I ran solo II (in a Fiat), I never worried about it...but probably should have. When instructing for law enforcement, there's no adjustment at all. Not even tire pressures.

 

Anyway, I've been building and racing something for a long time, but I'm in new territory here. I look forward to more seat time and meeting a new bunch of racers. Thanks!

[Joshua]

I drive a Miata on the street with 700/450lb springs, pretty stout for a small, light car, and find it acceptable. My advice is to do the spec suspension and live with a firm ride. The car will be better balanced on the track, and you'll get to experience the car the way you'll be driving it down the road. Plus, you won't have to work on the suspension twice.

[TurboShortBus]

BTW, I think I read that those upgrades will add so many points to the classification that my 944 won't be competitive in TT.

Note that there is usually a big difference between Car X that is built for a spec class and the same Car X that is built specifically for TT. It is true that many modifications that are allowed in the spec class will cost points and won't really make a performance difference in TT (like small front chin spoilers), and many of the worthwhile TT modifications are "too much" or illegal for the spec class (like Hoosier A6 tires).

 

Shocks and springs are common modifications to nearly all TT cars, so it's safe to change those and take the points for them. Save your stock sway bars, though, as many TT cars are still competitive with the stock ones in place (and they spend those +2 points on something else that will make a bigger difference).

 

When in doubt, resist the urge to make too many modifications at the HPDE level (or, don't make modifications that can't be easily or cheaply reversed). Save the money for HPDE seat time and consumables for the time being.

 

Mark

[speedshopjones]

All very good advice. Thanks!

[rsrdan]

350 or 400 are fine..even for the street...IF you wanted to you could run the stock sway bar for the street,then throw on the track sway bar...or disconnect the sway bar for the street ..trust me it's not stiff,until you attach the sway bar. Good luck!

[Varkwso]

BTW, I think I read that those upgrades will add so many points to the classification that my 944 won't be competitive in TT.

Note that there is usually a big difference between Car X that is built for a spec class and the same Car X that is built specifically for TT. It is true that many modifications that are allowed in the spec class will cost points and won't really make a performance difference in TT (like small front chin spoilers), and many of the worthwhile TT modifications are "too much" or illegal for the spec class (like Hoosier A6 tires).

 

Shocks and springs are common modifications to nearly all TT cars, so it's safe to change those and take the points for them. Save your stock sway bars, though, as many TT cars are still competitive with the stock ones in place (and they spend those +2 points on something else that will make a bigger difference).

 

When in doubt, resist the urge to make too many modifications at the HPDE level (or, don't make modifications that can't be easily or cheaply reversed). Save the money for HPDE seat time and consumables for the time being.

 

Mark

 

Well stated Mark...

[944-Spec#94]

BTW, I think I read that those upgrades will add so many points to the classification that my 944 won't be competitive in TT.

Note that there is usually a big difference between Car X that is built for a spec class and the same Car X that is built specifically for TT. It is true that many modifications that are allowed in the spec class will cost points and won't really make a performance difference in TT (like small front chin spoilers), and many of the worthwhile TT modifications are "too much" or illegal for the spec class (like Hoosier A6 tires).

 

Shocks and springs are common modifications to nearly all TT cars, so it's safe to change those and take the points for them. Save your stock sway bars, though, as many TT cars are still competitive with the stock ones in place (and they spend those +2 points on something else that will make a bigger difference).

 

When in doubt, resist the urge to make too many modifications at the HPDE level (or, don't make modifications that can't be easily or cheaply reversed). Save the money for HPDE seat time and consumables for the time being.

 

Mark

 

 

Correct. Most 944 spec cars will point out in Mid Range of D or the very top of E. What really hurts is weight reduction where we get nailed with 15 points or so. Spring, shocks and sway bars are not too bad and pretty common on most cars anyway. The other area that hurts us going with 924S 5th grear costs 3 pts and the LSD for 1 point. Stuff like this is not big gain for the cars, but are pretty common on the best 944 spec cars.

 

It might be possible to request a reclass based on hp / weight once stripped as even fully built we pass the F limits power/weight. Best place for 944 spec built to limit of class rules is PTE/TTE. Even so we probably can't complete for a win if a well build and well driving E car shows up.

 

For now don't worry about being competitive in TT. Just run and learn. By the time you can run to the limits of the car you will be ready to race in 944 spec anyway.