Here's my setup:

'06 Evo 9


suspension: Megan coilovers, 447# (8kg/mm) F, 600# rear springs
ride height: 25 1/2" F, 25" (from ground to center/highest point of fender openings)
Whiteline KCA395 roll correction kit (front)
stock swaybars front and rear

weight reduction: front and rear bumper bars removed, AMS moustache bar eliminator, trunk trim removed, rear seat removed, Muse Motorsports small battery mount with Odyssey PC680 battery

wheels/tires: Rota DPT 18" x 9.5", 35mm offset, Nitto NT-01 275/35-18

brakes (not that it really affects handling): stock rotors, stock calipers; Technafit S/S lines, Castrol SRF fluid, Hot Lap Motorsports cooling ducts w/ custom inlets, Hawk DTC-70 front pads, Carbotech XP10 rear pads

My previous alignment (with 245/40-17 Dunlop Direzza Z1 Starspecs on 17" x 9" Kosei K1-TS wheels) was 3 degrees negative camber front, 1 degree negative camber rear, zero toe (within .05 degrees, anyway) front and rear. This was before adding the Whiteline roll correction kit, which actually takes AWAY some static camber by relocating the outboard ends of the LCAs lower.

I wasn't happy with the front grip on-track, and I felt some instability in the rear under braking... I found some thread where somebody mentioned adding the Whiteline rear bumpsteer kit seemed to tame that, but I'm wondering if a tiny bit of toe-in in the rear might also make the car more stable, without really sacrificing any ultimate grip.

Thanks in advance for the help.

 

the bump steer kit helps a considerable bit. I've never run toe in, but I've run several toe-out settings and decreasing toe-out greatly improves that braking instability... which leads me to believe that a bit of toe in would help. I've seen no adverse affects from installing the bump steer kit though and now run some toe out (1/16" total) without the instability.

 

On thing to consider when setting rear toe is the effect of squat to toe.

considering toe out helps the rear rotate in corners, you have to weigh the straight line stability factor against any gain in cornering.

Personally, and this is largely for gravel but also for Tarmac Hill Climbs, I prefer TOE IN because I will take stability over rotation any day of the week. Why? Because I can FORCE rotation but cannot force stability.

Put those two factors together and set up properly and you get toe IN under neutral and off throttle and toe neutral under squat, load and acceleration.

The BEST of both worlds in my opinion. And completely stable.

Best of luck,

Scott
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Toe-in in the rear will make the car understeer even more. Under braking, the rear suspension goes into a toe-out situation, which is why evos have the disconcerting tail-wag under braking. That bump steer correction kit eliminates this. 0 rear toe is usually the best

You might not have enough rear camber, that may help as well, but it will increase grip in the rear, so you might get more understeer.

 

Only with excessive toe in. Compressed neutral will give the car nice rotation with the ability to stop the slide with throttle. The problem with the stock EVO settings has more to do with over sprung/under dampened than anything else. That's where the hop comes in and with the toe ever changing with that kind of rapid compression/decompression, you get erratic handling.

Toe out will only create MORE toe out under compression and some less under braking, but still promotes rotation. Which, in order to stop a car from rotating, you apply throttle and create MORE compression on the back end... thus creating MORE toe out and more rotation even when you are trying to straighten the thing out.

At least, that's what works for me.

Scott

 

I didnt say run toe out. On Tarmac, any toe in (I have run less than 1/16th of an inch or ~.5*) and it made the car noticably understeer. 0 toe is the way to go for a road car.

 

Thanks for all the input people... I'm wondering what yall think of 3 degrees negative camber up front though.

About right? Or maybe too much in combination with the front roll correction kit?

RaNGVR-4, are you saying that the Whiteline KCA388:

http://www.maperformance.com/whiteli...ction-kit.html



- will eliminate or greatly reduce that rear-end dartiness under braking? And do you have this kit installed on your Evo5?

What is the deal with that eccentric tube? How are you supposed to orient that?

I'm wondering if I should bump up the rear negative camber from 1.0 degree to about 1.2...

BTW, since I've read that people feel the OEM rear wing DOES improve stability at speeds over 100 mph, I am running the stock wing on my Evo. Also, to clarify, I felt that dartiness under hard braking at peak speeds of about 130-135 mph.

 

3 degrees may be enough, or it may not. The only real way to tell is how the car feels, and by using a pyrometer to measure tire temps across the tire, and evening them out. if the temps are way higher on the outside edge than the middle and inside, you dont have enough camber.

The bumpsteer kit basically makes the rear toe change less under suspension compression and extension than it does stock. The rear wont toe-in as much under acceleration (compression of the rear) so the car will be a bit more neutral. Under braking, you wont get as much toe-out change, so the car wont wag the tail as much.

I don't have it, but it is on my list of things to get. My car certainly has the tail wag under braking.

One downside I see from the kit (purely observational, never tested it obviously) is you wont get as much rotation from trail-braking because the rear of the car wont be as loose, less toe out under braking. Who knows if thats the truth though.