Larry Herman

What kind of LSD are you running and what kind of front control arms?

333pg333

Motorsport 50/80 LSD and Racers Edge control arms with their billet hubs.

944CS

what's the relationship between your tie rod and control arm? Your car has to be lower than stock, the less angle you have in the tie rod, the faster the car will turn.

Larry Herman

Good stuff Patrick. A racing LSD with at least 60% lock on the decel will help with braking stability, so unless it needs repair, that is one item eliminated. The Racers edge arms & ball joints are certainly beefy enough to stand running on highly (?) lowered cars.

How much did you have to raise it? Maybe you can bump the spring rates enough to prevent bottoming and set the car back down to where you had it.

trackjunky

I found that anything less than -3.0 degrees camber in front was a waste of time. These cars are very sensitive to ride height and camber, especially up front. You can really dial out the push with extra camber.

I agree with Larry in that I ran 0 toe in the front and a about 5 minutes toe-in in the rear.

Larry Herman

Damn, Bill. Every time I see your car I get a hard on. That thing is so pretty!

333pg333

Hey would you two like us to give you a little private time? lol

So the car was pretty low but we had to raise it by about 2cms from memory. Coupled with this, it's actually a different chassis and body so we just put the ride height to what it was. It does look a bit high.
What I can do is get some camber plates (probably also REdge) which unlike my KW ones, will allow us to lower the perch but not get any closer to the bump stops....if you understand what I mean. Some camber plates sit up proud and others are flush.

I've had really big neg in the past but now run about 3. I need to re check everything. The rears look like they could use some more neg. What's the downside of that? If the front gets darty up front, what does increasing neg in the rears result in? Better rotation of the rear of the car? Currently the rear seems to react at least as fast as the front, if not quicker. If anything wants to step out it's the rear....but then that could be as a result of what's happening up front. It's a long and winding road this learning curve!

Dubai944

If you are at less than optimum settings, more rear camber should add a bit of grip and reduce the tendancy to oversteer. Try adding some rear camber and rear toe-in and see if it settles the rear end down.

The front end shouldn't be darty, unless you are running a lot of toe out. Do you have any bump steer adjustment?

333pg333

Ideally I'd like to reduce some toe out up front as this is renown for inducing the dart under brakes...but I don't want to lose turn in. We can add a bit more rear camber and perhaps some toe in.

Bump steer adj meaning bump on the shocks or other? I have bump and rebound on the KWs.

Dubai944

I have never had a problem with darting under brakes even when running toe out, although on the smooth tracks I run on you won't get as much side to side uneven effect as you would on bumpy old aussie tracks.

Are you using drop pins with the racers edge arms? You might be geting some bump steer - change in toe setting on the front end with suspension travel and compression. Worth doing a trace to see how much change you get from full bump through to full droop. You may need to drop your tie rod ends.

333pg333

Hmm, not sure. How much difference will the ride height have on these symptoms? I had to raise the height due to running out of free travel. If I change the camber plates I can lower it down again. Would this in itself change anything more than the roll aspect?

333pg333

I'll have to check into this Steve. Thanks.

Larry Herman

Bumpsteer can be a huge factor. Didn't think to mention that.

Depending on the orientation of the lower control arms, you could be getting massive toe-out on suspension compression. I do like the idea of changing the camber plates, that certainly is a lot less work to see if lowering back down helps.

Skip Wolfe

Agree with that. I am running 2 mm toe out in the front and the same amount toe in on the rear and never have had the car feel darty under breaking.

Also agree with the adding rear camber and toe-in on the rear to settle the rear down, but the there is also your rear swaybar and rear shock settings to play with as well.

Van

For you guys running lots of negative front camber, how's your tire wear? I find with 2.5 degrees (and a pretty stiff suspension) I wear out the insides. I don't think I'd get more than a dozen heat cycles out of a set of tires with 3.5 degrees neg camber.

Patrick, another suggestion for you, to settle the rear end under braking, would be to change the pitch of the car. By raising your front spring perches by a few turns, and lowering your rear spring perches a few turns, you'll "tilt the car back" which will give you less weight transfer away from the rear wheels in braking - thus giving you more rear traction/stability.

You can also do similar adjustments with your shocks' compression settings, if they're adjustable.

One final thought: sway bar adjustments (including having a sway bar disconnected) affect the car mid-corner. If, med corner you feel like you need more front traction to battle understeer, loosen the front bar or firm up the rear. If you feel that the car is not responsive enough on turn in, a sway bar adjustment won't help that.