Hi All,
Ran the Evo at Pocono North last week with Cartct. Nice group. Here's my list of mods: Works P2 flash
cat-back exhaust
Torsen front LSD
Tein flex coilovers
Perrin rear swaybar
Goodridge ss lines
Eradispeed 2-pc rotors
Ferodo pads
SSR Comps with Hoosier 245 dots
Track alignment -3 front camber, -1.5 rear 0 toe front and rear.
I ran the rear swaybar at full stiff, rear shocks at 5, front shocks at 10. Car still understeered. Disconnected the front bar. Still understeer and this is with front LSD. Ran mid 59's which I don't consider particularly quick but I'm only making about 250 at the wheels. For those of you running Tein flexes, because of the stiffer front springs, I would say lose the front swaybar. I don't know what it weighs but it's a lot of weight off the nose. CCW is building me a new set of wheels and here is what I'm trying next: 275/40/17 Hoosier fronts, 245/45/17 rears. Hopefully, this will get the car more balanced. Will report back.
Cheers,

 

Why not try the shocks a little stiffer in the rear?

 

Any stiffer in the rear and the car would skip in the infield. Softer in the front got jouncy. I will probably try a rear strut bar and v-brace.
Cheers,

 

I have played around with a 285/30-18 front and 245/40-17 rear to help reduce understeer in autox with limited success. From a vehicle dynamics perspective, this solution makes a lot of sense but the effect wasn't as dramatic as I expected.

 

Was the effect quantifiable? Lower lap times for instance? Was tire wear better? On the racetrack my car just burns through front tires.
Cheers,

 

What have you done to redistriute weight in the car? battery to the rear? Is the understeer you're encountering similar to a stock Evos power on understeer?

 

I don't have any conclusive data right now. I'm only running autox so the car speeds are low but I actually ran the same lap time with 285's all around and with 245's on the rear. My front tire temps were high with both tire combos. I believe the car setup needs to be different to maximize each combination. The car definitely feels different with narrow tires on the rear - you can feel the center diff working to keep the rear from spinning under acceleration. I haven't given up on the narrow rear tire option just yet.

 

will you consider swap the front spring to the rear....i don't remember the spring rate on Flex. But I believe with a higer spring rate in the back which can somewhat help the car rotate better.

 

That is one of the tricks I had waiting if I couldn't get my JICs dialed to a neutral point. WTZ, have you tried having the car corner weighted?

 

Moving to Motorsport Forum.

 

The car has been corner-weighted. Not sure about lowering the front spring rate as I am running with no front swaybar. Maybe I'll try stiffer rear springs. Met a guy at Pocono with an ITA Honda FWD and he was running 400 lb springs f and 700 lb springs r. The car was fast for what it was. Also will be trying to remove static weight from the front of the car. Will probably remove the front swaybar, re-locate battery etc. What would really help is a center diff that distributed more torque to the rear but I think we are talking megabucks to do that.
Cheers,

 

The car will respond to stiffer rear springs. I ran this weekend with 25% stiffer rear springs and no front bar. The handling was very neutral for autox. The car still has some issues with front wheelspin on corner exit but of course I don't have a front LSD.

 

Wtz, One other thing I noticed is that I am running significantly more camber than you were. This was on a road course at high speeds, but I've been running 4 degrees in front and 2.4 in back (on R compound Toyo Proxies RA-1s). That removed almost all of my oversteer. At the track my tires were wearing pretty evenly across the face.

I'm not sure if that would apply to AutoX, but you might want to see if bumping your front camber some will help.

 

Eroshi, I do all road course work. Not really into autocross. What spring rates are you running? With 500 lb. front springs I can't run more than -3 without burning up the inside front tire. Have you taken tire temps? Ordered wheels yesterday, 8.5w rear and 9.5w front. This will allow me to run 255 tires all around or 245 rears with 275 fronts.
Cheers,

 

Recently an Evo ran around a local circuit with bigger yokohama slicks in the back, 260s and 230s in front (18s ) and obviously had horrible understeer. This looked like a recipe for transfer case problems.

Have those of you running staggered F/R sizes had any center diff issues?