I started a thread in the WTBS forum on rake.

You can cut and paste your information if you wish.

https://www.evolutionm.net/forums/ev...bout-rake.html

 

Shadow, looks good man, I like the stance more now than your first picture. In the first photo it looks more like a classic drag car, I’ll bet the rake was close to 1 ½” before your change. And change is good, especially on suspension. I think we’re in a good ride height zone for a street driven, track, autox type car.

So what did we impact with these changes? Basically we’ve helped the roll axis of the car by flattening it out. By doing more at the rear we’ve also changed the way weight is transferring through the chassis, we‘ve slowed it down just a tad. This tends to improve cornering characteristics in general, but for the Evo it’ll help reduce the tendency to lift the inside rear and reduce the diving to the outside front at the same time.

 

Good analysis RT

My general (subjective) impressions were that the car feels more neutral in general, more "friendly" in terms of transition between oversteer/understeer on the limit and more "progressive" in terms of breakaway characteristics. Turn in etc. feels just as good as at higher ride heights.

I think your more scientific explanation is bang on. Thanks!

My current goal is to dial the handling in as perfectly as possibly on street tires before I slap some R comps on, and pretty happy now. In the past I thnk I've been guilty of using R-comps as a band-aid of sorts.

 

Cool! Your welcome Shadow, and your right, its worth the time an effort to try different set-ups. Had a chance to drive mine again yesterday and the front end feels much better. Still need to lower the tail to same height as yours, plan on having some corner balance work done in the near future so I'll make the next ride height/ chassis rake change at that time.

 

the term i would use to best describe the effect of rake(roll axis inclination, really) on car handling is yaw damping.

More rake=more yaw damping. RT's comments seem to agree with that as well.

 

Rake @ neutral accel. . .


Squat under full accel and also hitting a bump I think . . .


Another pic of how low it was when I first installed the shocks. . .


To show you just how much UP travel you can get in the rear before bottoming out

 

Nice! Maybe i have you confused with someone else, but are you running revalved Bilsteins?

- Andrew

 

No, my car as well as all the other past Showcase Mitsu evos are on Ohlins. . . A couple of us on the D/A piggyback aluminum models and a couple of us on the old Flag S/A model . . .

Jarrod

 

Rick Jung's (SS_RX7_R2) red STU evo is on bilsteins. That's probably the car you are thinking about.

d

 

Thanks guys.

- Andrew

 

whatb center diff ecu's do you run ralliart or programable one's

 

OEM center diff and controller and TRE rear diff.

 

Just curious...

EVOutionary...loooks like you raised the front a little since the earliere pics...and reason for that?

Also wondering if you set up the car to 'wag the tail' or do you go for a smooth driving style?

 

The reason, to be honest, is because we changed spring rates and just eye-balled things putting it back together to try to get shock length close to where it was. . . It worked, so we left it. . .

The car is the fastest when I can wag the tail a little bit. Dead straight grip driving is slower. The idea with the big rear wing is to set the car up so it is loose in the slow corners to help rotation, but as speeds rise the wing help control the rear to keep you from spinning out in high speed offsets or slaloms. . .

If you can ever find footage of Aaron Miller autocrossing the EVO - his driving style along with the Miller's chassis setup (another ex-Showcase EVO) is the epitome of "wagging the tail". The car is sideways more than it is straight. It is extremely fast, but it is really hard to be clean. He beats my SM EVO fairly often on raw time, even though we have 60+HP and aero and 200 less pounds. . .

 

the tarmac one makes a big gain in corner entire speed & mid to exit is minblowing also get a ralliart front super trax lsd set 45 to 55 ft/lb