evo setup for autox stock class

[JT-KGY]

Glad that I found this thread... I'll be taking my evo to autox
for the first time (been racing my e36 m3)...

I think I will just increase my front camber to -2...
Someone said that the hot tire pressure should be 42 front &
41 rear (stock tires)...???? Are all people agree to this?

Are rear strut bar allowed in stock class???

Chris in HB,
Wouldn't stiffening up the rear (rear strut bar) make the
car oversteer more rather than understeer???

[FT@SELGP]

Originally posted by JT-KGY
Wouldn't stiffening up the rear (rear strut bar) make the
car oversteer more rather than understeer???

I would not know the tire pressures, but the "strut" bar allows for less flex in the chassis, so the vehicle's composure stays more predictable, as well as balancing weight shifts from left/right; but not front/rear. Hence, I think classifying changes in handling characteristics as "more oversteer" with the installation of a rear strut bar is not quite the right way of describing it.

If we were talking about anti-roll bars, that is a different issue

[JT-KGY]

Ahhh.. I guess I had it all wrong....
I was assuming that strut bars would have the same effect of
anti-roll bars..

Well, so the consensus is that rear strut bar makes the EVO
push (understeer) more??

Originally posted by FSelekler


I would not know the tire pressures, but the "strut" bar allows for less flex in the chassis, so the vehicle's composure stays more predictable, as well as balancing weight shifts from left/right; but not front/rear. Hence, I think classifying changes in handling characteristics as "more oversteer" with the installation of a rear strut bar is not quite the right way of describing it.

If we were talking about anti-roll bars, that is a different issue

[FT@SELGP]

Originally posted by JT-KGY
Well, so the consensus is that rear strut bar makes the EVO
push (understeer) more??

No not at all, my point was that the drawing a linear relationship between strut bars and steering characteristics is not the way to think of them.

If your car understeers going into a tun or takes a little too long to settle and react to your steering inputs during transitional runs (read: slaloms in auto-x), then a front strut bar will help. If the vehicle turns in well, but the rear takes a little too much time follow the front (hence creating a misguided understeering feel), then a rear strut bar will help.

However, if you have under/oversteering issues in various types of turns and the car seems out of balance comparing front to the rear, not side to side balance; then anti-roll bars will help.

Obviously, I am not covering all possible vehicle balance characteristics, but just to give some idea.

[urbanknight]

From what I understand, a rear strut bar will add a little oversteer in general (but very little, and not as much as a sway bar). But I think what FSelekler is trying to say is that it won't simply make your car drift around every turn. It still depends on other aspect of the car as well as the driver's characteristics. If you brake late, you're going to push/understeer no matter what your car has.

No setting that aside, a rear strut bar or sway bar are not allowed in the stock class. But you can upgrade or remove the front sway bar. Now the logic behind getting a larger front bar is to reduce body roll, while some autocrossers remove the front sway bar in order to get more tracking on the front (although I don't know of any Evo drivers who have tried the latter).

As for tire pressure, I recall SSRX7r2 telling me he used something like 36 front, 44 rear, which I always thought to be extreme, but hey he's faster than me. When my Lancer was stock save for rims and tires, I was running 40 front 36 rear but that's a completely different kind of car, as it had plenty of oversteer thanks to the 0 camber.

Simply put, you need to do a race to decide on tire pressure. Chalk the sidewalls to make sure you're not getting tire roll (if the chaulk rubs off you're rolling the tires either by too little pressure or poor driving habits), and pay attention to the car's characteristics. If you are turning in properly and the car tends to understeer, take a little pressure out of the front or add more to the rear, and if you get too much oversteer (highly unlikely with the Evo), take pressure out of the rear or add to the front. You will be maazed at what 2-3 psi will do.

[JT-KGY]

Taking my car to the track tomorrow... this is my current setup...

Front camber: max at -1.9/-1.8
Front toe: 0
Rear camber: -1.4/-1.5 (factory)
Rear toe in: 1/32" (almost 1mm which I think I need to increase)

[JT-KGY]

Also... did anyone find alignment adjustments in the rear a bit
hard to get it right?

I mean.. I loosen up the bolts, set it to where I want it, then
being to tight it back up... but the setting start to change as
I tight it back up.... Did you guys have that problem?.. Anyway to
make this any easier?

I also find the meters on rear toe-in quite useless... i mean each
click is 1/8" which is already way too much...

[urbanknight]

When you say track, does that mean I'll be seeing you at the Solo2 at Ca. Speedway on Sun? Or is this something different?

[JT-KGY]

Close but not quite... I posted the msg on Friday... so I was
at CA speedway on Sat (today)...

Originally posted by urbanknight
When you say track, does that mean I'll be seeing you at the Solo2 at Ca. Speedway on Sun? Or is this something different?

[urbanknight]

I didn't make the cut for the autocross practice, so I was only there on Sun. But if anyone cares to know, my Lancer finally found a nice balance with -1.5 front, -.75 rear. Trail braking was a little too easy (need to reduce tire pressure) and overall very stable throughout the corners.

[JT-KGY]

I see... how did you do? What is your rear toe-in setting?

I'm thinking of reducing my rear camber to around -1.0
(my front is around -1.8)... but increasing my total rear toe-in from
1/32 to 1/16...

Originally posted by urbanknight
I didn't make the cut for the autocross practice, so I was only there on Sun. But if anyone cares to know, my Lancer finally found a nice balance with -1.5 front, -.75 rear. Trail braking was a little too easy (need to reduce tire pressure) and overall very stable throughout the corners.

[jbrennen]

Originally posted by JT-KGY
I see... how did you do? What is your rear toe-in setting?

I'm thinking of reducing my rear camber to around -1.0
(my front is around -1.8)... but increasing my total rear toe-in from
1/32 to 1/16...

What's the motivation behind those changes? What tires are you running?

I'm asking because the conventional wisdom (assuming you're on competition tires) would be to increase rear camber and decrease toe-in, perhaps even running some toe-out.

[urbanknight]

My toe is currently at standard specs. I think that's zero on the rear and 5/16 on the front. Seems to be very stable, I just need to relearn the car and stop braking late. My brother got similar times with almost no experience drivin my car, so I can't blame anything but myself for today's performance. Although having only 2 runs (they were running out of time) made it very difficult as well. Next time...

[urbanknight]

jbrennen, on the Lancer/Evo, I thought the general plan of action was to increase FRONT camber and toe-out. So he is doing the other side of it by reducing rear camber (my guess is to keep it street friendly). Although I know an Evo driver who gets decent tire wear with -2.5 front camber, but keeps the toe at about zero.

[JT-KGY]

Ya... I'm doing that to reduce some understeer... I like the car
to be just a tad more neutral... (though it could be that i am
over-driving my car... it's my first time at track with evo)...

I'm running oem tires... I would increase front camber but it's
already at max factory allowed camber....


urbanknight,

I think you got it backwards... the factory spec says that front toe
should be zero.... and total rear toe in is around 1/8".....



Also, maybe i'm used to M3's torque... I find EVO's turbo lag
almost unbearable.... trying to come out of a slow corner... it
takes almost 1 to 1.5 seconds before turbo kicks in with full
throttle.... I post a separate thread...
Turbo lag at autocross