Protocav

I have been dealing with a little bit of corner exit understeer, and I’m looking for ways to cure it. The car turns in sharply and holds it’s line through the apex, but pushes when I get back on the gas. I realize that I could take a later apex, or wait to get on the gas, but I wonder if there is an obvious suspension setup detail that I’m missing to reduce this specific understeer.

Shocks are stock, so I can’t increase compression damping in the rear. Front camber is -2.8, rear is -1.9, tires are 245/305 Nitto NT-01’s. I’m thinking that a wider front tire, or spacers won’t really do the trick because there is such little weight on the nose at this particular time. looking for options other than sway adjustment because adding front grip to cure this problem will simply reduce rear grip, so I will probably just end up with corner entry/exit oversteer.

Any thoughts are appreciated.

997gt3north

what are your rear toe settings?

- drop front ride height
- run the cup front splitter
- add c.f. bling front canards
- drop the rear spoiler rake
- add 1-2 rear tire psi
- drop rear camber to -1.75 (I run this)

Protocav

Rear toe is 15 minutes per side.

All of those are good suggestions. I think the aero will be negligible because I am only around 50mph during the push, and the other suggestions reduce rear grip.

I want it all I want to keep my rear grip and gain front.

996FLT6

What's your swaybar setting at and like above what's the toe up front. Toe out in front would help if it hasn't been done. Mike

Tom@TPC Racing

Agree with good suggestion by gt3north. If you have adjustable shocks add a click or two of rear compression to reduce squat and/or take out a click or two of front rebound to keep the nose from raising too quickly.

Edit: Sorry I missed the parts on stock shocks. Shameless plug- DSC...

TRAKCAR

I don't understand.
Where are they set now? If your only problem now is a bit of early throttle low speed understeer fix it with bar is OK?

Other than that LSD and car rake did the most changes for me.

wanna911

Don't assume that you will go straight from understeer to oversteer with a sway bar change unless you have tried it. It could be the happy medium you are looking for.

Ride height adjustments do the same thing. They transfer weight to the front of the car, giving that end more grip, well guess where that weight came from? Keep going lower in front and you will have a tail happy car in no time.

Handling is all about weight transfer and balance. Depending on how bad the situation is I usually start on the end with the problem and doing ride height adjustments. Simply because you have an almost infinite amount of settings within the acceptable range. You have to limit how much you change because it will start to affect your alignment. (assuming you are making changes at the track).

mark kibort

more rear bar.

don't think toe out in front will help, if this is a hard slow turn exit. generally, the front outside wheel is lifting up anyway, and it does kind of desensitize the steering wheel if you are a little soft up front too. (bump steer effects).

sometimes a little toe out in the rear will loosen it up on exit of turns. often, some of the geometries naturally toe in the rear under compression and that can tighten things up in the rear. a little toe out will help the rear rotate a little more. it made a nice effect on mine going from slightly toed in to 0 toe. I have a nasty push too. but I think much of mine might have been a blown rear shock. before that, I remember tire stick was the major factor .

997gt3north

Am I correct that the NT-01s (245/305) in 18s actually have a rear tire that is shorter than stock - and thus the combo with this car has effectively dropped the rake? - might be that simple.

The other way to think about it is as a challenge - how much additional entry speed can you carry in and use to slightly increase entry rotation so that this is no longer a problem - you might need to kick up your uncomfortableness to a new level.

Another solution is to increase the rear spring rate by 100#s and install the TPC magic box

JustinL

It is difficult to wrap our brains around it from an emotional perspective, but the goal is to go faster, not increase grip. You may not be able to increase front grip very easily, but will improve your time if you get the car better balanced by reducing rear grip.

I would start with stiffening the rear sway bar.

Veloce Raptor

Let the car rotate a tiny bit more before going to power...and go to power more gradually...in order to keep the front tires from unweighting so dramatically & shrinking the front contact patches...

Spyerx

If I did my math right on the NT01 in 245/305 it's very, very close to stock differences. The 315 is quite a bit shorter in rear.

certz

Hire a race coach for the day. What the seat of their pants tells them can be quite different from what yours is telling you.

997gt3north

sorry - it was the 315 that is the short tire - should know i have a set in the shed

Protocav

The sways are set up full soft rear, and one hole from full hard front. I know that this setup sounds pushy, but it enables me to drive really deep into the turns without loosing the tail, and only manifests itself as push at exit.

Car is minimally toe'd in at front. This is a street car as well, and I don't like the wander that is generated with toe out

DSC will adjust rear compression damping for this situation?

This is my first thought, and this can be tried without modifying the car. I always say that getting around a track very quickly is "being comfortable with being uncomfortable"

True, and adjusting the rear sway is an easy test.

I think this, combined with more entry speed / trail brake could be the answer. The throttle patience is tough.

I've had pro drivers sit with me before and they never made comments about car setup (perhaps because their team handles the details). they have made comments about waiting to get on the power. I can definitely work on that, but was looking to see if there was a minor car setup detail that I was missing.