But what is the correct combination?

A bigger front bar will serve to reduce or eliminate the lift of the inside rear tire. But it also transfers weight from the IF/OR diagonal onto the OF/IR diagonal -- thus, even further overloading the outside front tire. A smaller rear bar will have much the same effect, at least until the IR tire leaves the ground, at which point the rear bar is just extra weight.

Under ESP rules, are there any legal means to combat the other problems you mentioned? Can you significantly raise the car's roll center, or alternatively, significantly lower the car's CG? In SM, raising the roll center is conceptually easy -- the entire suspension from the attachment points out can be redesigned -- but actually doing it and making the car faster around an autoX course would be a very time-consuming and expensive task.

Track width can be increased, and of course you can run very stiff springs, but even those won't always serve to keep the inside rear tire planted, they'll just reduce the lift. Look at these pictures of Dennis Grant's car, with a fairly wide track and very stiff springs: http://members.aye.net/~racerx/sm_dennisgrant2001.html

I'm not sure what spring rates Dennis was running back then, but his web page (http://www.wincom.net/trog/car.html) shows that he now(?) runs 900 lb/in springs in the front -- that's ultrastiff.

I happen to think that the first of the two pictures of Dennis' car is pretty close to where I'd like to be. The inside rear tire is just at the point of being totally unweighted without actually coming up off the pavement.

 

uhhh, you sure about that



FWIW, I ran a stiffer front bar for only one event. The change in dynamic spring rates was enough to induce enough understeer to cause problems on corner entry to the apex. I am not sure if we need to worry about the front swaybar in the EVO. Besides it's a beotch to install...

 

I talked with John Mueller about this when I ordered my JICs this week. He basically (he gave me the technical jargon I sort of understood ) told me that the JIC suspension will help with that, but getting handling correct is the most important part. That losing the traction of the one wheel is unfortunate, but if you can relegate it to ultrasharp lowspeed turns and keep the car oversteering properly your good.

 

Roll center height changes with ride height and should be one measure for selecting ride height. DG's car is not that stiff even with 900# springs. Wheel spring rates are the only way to compare car setups. In SM there are plenty of variables in order to keep the inside rear from lifting high off the ground. That's not to say that it will be carrying a lot of weight under all cornering conditions.