Ok, so I have been pushing my Evo X hard as hell for the past 4 years at the racetrack (roadcourse)

I have upgraded brakes, ducting cooling, and suspension and I am still getting understeer and chassis shudder when trying to rotate the back end in tight corners.

Here is what I have done to the suspension =

Whiteline swaybars with adjustable end links

750lbs swift springs up front, 850 in rear

AST adjustble coilovers with vorshalg camber kit setting the front at 3.5 degrees of camber and the back at 2.5 degrees

I have adjusted the coilover settings from full stiff to full soft and everything in between...

Car has been lowered around 1.5 inches all around (I forget the exact amount front an rear)

Whiteline front rollcenter kit with adjusted geometry to add up to 4 degrees of camber when hard cornering

I use Nitto NT01 tires which admittedly are not as sticky as Hoosier R6's - but they last a looong time with tracking a car as much as I do...


SO

What's the deal guys?

How can I get this car to rotate in the turns? I don't need it to spin like a top, but it does seem to dig in its nose and understeer real bad, especially in high speed tight turns...

Ideas?

Is downforce the answer? Should I start looking into aero kits?

What else is there that I am missing/ doing wrong?

 

well if you are trying to get the evo to oversteer i would reduce the camber in the back to -2 or -1.5 that way on a turn the contact patch will not be as big allowing for an oversteer situation. Also change the front camber to -3 if possible.

 

Yes, agreed with the guy above me. And if you want to go more extreme, get a small toe out in front and toe in, in the rear. C

 

This was my first thought too.

Also maybe a rear differential upgrade.

Is this an HPDE car or a TT/W2W car? Do you have classing to worry about?

 

This would work due to the toe out in the front but adding toe in the rear would make it less effective. You'd want either zero toe in the rear or if you really want some excitement toe out in the rear. Toe in at the back makes the rear less likely to come around not more.

 

Try this next time you're at the track too (see attached)

I'd stick with the -3.5* camber in the front. Try -2.0* in the rear first, then go to -1.5* if it still isn't rotating enough. Rake will help with rotation as well, so you can look into either lowering the front, or raising the rear.

 

You noted Sway bars in the plural. If you are running a higher rate FSB w/the uprated front springs, did it ever occur to you that youre maybe over sprung?

Big bars & soft springs or Soft bars & big springs. Its one or the other

If I read your post wrong & you have not uprated your FSB, excuse me. You may just be simply over driving

 

I agree with what Minus said. I think it's a combo of the big bar(s) and over driving that may be causing your understeer. With springs as stiff as yours I'd stick with stock bars front and rear. If possible have someone watch your corner entrance on the turns you have the biggest issue with understeer to see if you're lifting a rear tire.