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Lowering the Ride Height.. Advice?
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TOPIC: Lowering the Ride Height.. Advice?

Lowering the Ride Height.. Advice? 10 years, 3 months ago #14887

  • karbuf
  • Comp School
  • Posts: 33
Question: What is good ride height for road racing the 944?

I'm building an '88 944 to race in the Chump road racing series. We are allowed to make some mods to suspension to lower our ride height.. I know how to index the rear torsion bars and can cut springs to lower front.... so I know how to do it, but I'm not sure how far to go.. I have tools for measuring caster/camber/toe and bump steer... But I would appreciate any insight from anyone who has actually done this before.


Re: Lowering the Ride Height.. Advice? 10 years, 2 months ago #14894

  • AgRacer
  • Administrator
  • Posts: 712
I cant even begin to give you an answer as I have no experience setting these cars up. Those on here that can would like to know what springs/shocks/torsen bars your running because that can change what your optimum ride height can be. I don't know if sway bars have anything to do with it. I haven't gotten that far in learning about setups and adjustments on sprung race vehicles.
J. Stanley
NASA-SE Region 944 Spec Series Director
Yellow #60

Re: Lowering the Ride Height.. Advice? 10 years, 2 months ago #14899

  • karbuf
  • Comp School
  • Posts: 33
Thanks AgRacer.

Everything has to remain original stock in this class although we are allowed to make some "adjustments" (ie cutting springs).. I know that will affect the stiffness of the spring.. etc..

Springs are stock.. I have not cut them yet, so I dont have a rating on them yet, but it would be very helpful if someone can recommend a rating that I can shoot for, which would affect how much I cut..

My '88 has 25.5mm torsion bars, 26.8mm front sway bar, and 18mm rear swaybar. If someone can give some guidance/recommendations here, it would be appreciated

But I'm also interested in what happens with suspension geometry in terms of caster/camber/bump steer/roll center.. and what affect that has on handling and tire wear.

I'm just looking for a recommendation on an initial set up.. we are allowed to remove a lot of extra parts from the car and as a result the ride height has lifted up a good bit.. so, since I have to lower it back down, I'd like to get the cog as low as i can without killing the geometry.

It's the 944-limbo... "How Low Can I Go?"

Re: Lowering the Ride Height.. Advice? 10 years, 2 months ago #14904

Just a couple of weeks ago I drove in the 24 hours of Lemons at Chuckwalla Valley Raceway and had a blast, there were several 944's, I was in a friend's 1989 300zx I think, it looked like a bumble bee, so I am not sure what it was.

I have only lowered a car or two with stock suspension and did it for street use, but not to drive 10/10th on a race track, so what I know is, taking weight out of the car increases spring rate and I am pretty sure cutting the springs will do that as well, I don't think that lowering the rear effects spring rate, so that might create a bit of a push. My race car is 4 1/2 inches at the rocker panels, so I don't think I would go more than that. Obviously your going to have a lot of roll and without a LSD your going to pick up the inside wheel and spin quite a bit, if that happens, you might experiment with disconnecting the rear sway bar, which can create another reason for pushing??? As for what is the geometry of your suspension when your door handles are dragging the ground??? I would think you might be eating the outer edges of your tires regardless of ride height and I am not sure what your toe does, maybe goes positive ?? If you haven't done one of these races before, I think your going to find that finding that extra few tenths in set up isn't going to win it for you, but more about not breaking and just being consistent with lap times. I drove the bumble bee first on the second day with close to 120 cars on track, and drove for 1:20 minutes before I was out of traffic for more than 3 or 4 seconds, never passes so many cars in my life!

Have fun!
Norman #99
The following user(s) said Thank You: karbuf

Re: Lowering the Ride Height.. Advice? 10 years, 2 months ago #14912

On stock springs, I'd probably keep the ride at or above 5". Keep the car level. To much risk of taking out the oil pan. Max out caster, and run lots of negative camber - -3.5 in front and -2.5 to 3 in back ( or as close as you can get stock). I agree with Norm on the handling issue. Cutting the front springs too much could cause a big push.
Eric Kuhns

National Director Emeritus

2007, & 2008 National Champion
2011, 2012 2nd
The following user(s) said Thank You: karbuf

Re: Lowering the Ride Height.. Advice? 10 years, 2 months ago #14917

  • Tabbasco
  • Junior Racer
  • Posts: 61
This will not make sense but it is true...we also are racing in CC/Lemons. The car has been stripped to 2350 empty so it was riding pretty high. We lowered the front with spring clamps and could not lower the rear due to some stuck bolts so we tracked it to get a baseline...

Completely nuetral handling and it was getting quite fast before we had some engine problems after six sessions. I could send you our alignment specs but the key is ride height in this car and somehow we were the blind squirrel that found the nut.

We had plans to re-index etc and now we are going to leave it as is!;viewImage=1899751
HPDE Driving Instructor
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