deputydog95

I was at Sebring this weekend for PBOC winterfest. I saw a ton of GT3's there. Many lowered well below stock ride height.

I don't daily drive my car, but I do drive it on the street some and track it fairly often.

Its currently at stock ride height. I'm finally getting used to driving it without dragging the lip everywhere. While I know it will be harder to deal with that front lip if I lower it, is there a major handling advantage at the track by dropping it another 20-25mm?

Izzone

Lower it; you could throw sparks if you hugged the corner in 17........

deputydog95

Have you dropped yours? It appeared that way, but it's always hard to tell when people are running different wheel tire combos.

Izzone

Nope, mine is stock height

2.5 neg camber front and rear

Must be the shaved ra1

You need to go see John at ccw

CRex

Lowering all four corners by the same amount won't affect your handling. That said, I started scraping my rear brake ducts at some point and cracked one of those plastic mounts on the duct. Just don't overdo it--our cars don't have much of a ground effect to begin with and the benefits to lowering are aesthetic more than functional.

Carrera GT

In the 997.1 GT3, the book has a "race circuit" setting which includes a lower ride height. I try to get the rear lower control arms at a "mid point" (usually horizontal) and I seem to recall that was the result this race circuit height. I think the 997.2 GT cars don't have a "race circuit" setting in the book, but I'd use the lower control arms as the gauge. Then a corner balance to keep it planted on all fours ... so it can go "up on three" ... : )

As for advantages to "correct" or just plain lower ride height, there are man -- off the top of my head:

suspension travel and action
-- reduced bump steer, more "reach" (extension aka droop) to counteract unweighting
-- less compression travel (roll tending to induce weight transfer, bump steer, loading the outside, unweighting the inside)

aerodynamics
-- less lift pressure (slow air trapped under the body, in the front or sucked in under the side skirts)
-- reduce flow separation (under the car at the rear, causing less drag off the rump)

In short, go low, limbo ...

http://www.youtube.com/watch?v=hFyLDdcIHh4

lawjdc

If you run 18" with 315/30 and 245/35 R6 Hoosiers you will be about 1" lower. Just about perfect.

FTS

How about bump steer; how do you compensate when lowered that much?

mobonic

I disagree, the lower the car the lower the center of gravity, which will result in better handling and better weight transfer.

Also it improves aero... you want to go as low as possible without bottoming out or tearing off parts...

IMO if you can see the top of the tires in the wheel well... you need to go lower.

Next time you go to an ALMS race.. see how low those cup cars are in GTC.

deputydog95

For folks that are damaging body parts underneath, just how low are you?

I was considering a corner balance as its never been done on this car. I did it on my 996 and it felt a little more balanced afterwards.

Might as well adjust ride height while they're doing it.

Is there a height that is a compromise between performance on the track and not ripping body parts off while on the street?

utkinpol

when i got jrzs installed car was lowered may be half inch lower than ROW sport, there is a limit there with stock uprights - you need to maintain proper angle between arms in front suspension, i do not remember details but essentially there is a limit unless you go with cup car uprights. plus if you sit your car close to ROW you do not need bump steer correction arms.
after you got front lowered rear axle sits half inch higher than front.

TRAKCAR

I'm lowered 10mm from factory ride height, maintaining the factory rake.
I would not lowered it too much for Sebring. IMHO most cars are too low and start bouncing more..

Izzone

And you said all stock......so now I know how you get those lap times......super glue on your tires and a lowered car

Z06

When you lower your car it does improves handling and braking.. by slowing weight transfer... aero improves by less air traveling under the car, this gives more down force, creates a low pressure area.

You can go about 8ish mm before you need to get the adjustable bumpsteer arms with spacers. One easy way to check is to see if the toe arm is still level, straight.

I have my car lower about 15mm. Now when its this low in the city with stock soft shocks/springs it will sometimes rub, with the Bilstein DA no problems.

For track use changing to 18" wheels will help lower the car without bothering the set-up.

TRAKCAR

LOL