burglar

I'm running street tire CS this season, and I'm going in for my alignment in the next few weeks. Let's make sure I have this all right.

Currently, the car sits as I purchased it. I have no idea what the alignment is set to, but based on what I could tell of the previous owner, it should be factory.

The car currently turns in a little sluggish, pushes a bit on corner entry, settles down mid corner, and then transitions to light oversteer once fully set, especially under power.

Based on this informative link, I'm guessing that I have some toe front and rear, and insufficient camber all around. The front end alignment is causing my turn-in and entry problems, while a conservative rear becomes a crappy contact patch once I have a high rear roll angle. Sound right?

Looking at the STX thread, camber is all over the place, but in general, rear is around 0.5° less in the rear than front. On stock springs, I'll get way more roll than the coilover guys, so I assume I'll need to try and max out the front.

Caster, if I understand it, should give me dynamic camber gain at higher steering angles (aka, autocross speeds). I think I read an Isley post once concerning sacrificing a touch of camber to keep caster high, but I can't find it. Comments?
EDIT: Jason himself said I have this backwards, which means I should go for big camber, even if it means sacrificing some caster.

Toe is usually 0 F&R. Any drivibility issues for those with 0 toe all around? I'm still going to be a street car.

As it stands, the plan is to ask my guy to max out front camber and caster, set rear camber to 0.5° less than whatever he could get out of the front, and go 0 toe all around. Then tweak from there. Any major faults in my logic?

Thanks guys.

chiketkd

iTrader: (5)

I would say that's a very sound plan. Should give you a good starting point. Are you still on stock shocks? If yes, TireRack has the koni sports on closeout. I'd get a set and then do an alignment.

ULLLOSE

iTrader: (1)

You have that backwards.

burglar

Fuzzy memory in my old age. I'll update my original post for correct records. Thanks!

fossumja

iTrader: (4)

For stock-class setup, the general rule of thumb is to get as camber as possible in the front and then balance the rear to taste. I would probably go for a touch more camber in the rear, but this is largely down to driver preference.

With 1.8 deg negative camber and ~zero toe all around I have no abnormal wear problems in >25K mi of street driving.

Jim

auzoom

Hang on ... isnt that still back-to-front. Camber is only useful while cornering (camber pointing straight ahead is pointless as you want as much contact with the surface as possible).

I thought that it was that the more castor you had the more dynamic camber you will get, ie when you actually turn the wheel, the camber will be greater with more castor than without it.

This is what I believe ULLLOSE was referring to. Correct?

ULLLOSE

iTrader: (1)

No. If you are turning the wheel to the point where caster is more important than camber, you are doing it wrong.

auzoom

Lol. Not saying one is more important than the other, what I was getting at is that if you have say 2 degrees camber while pointed straight ahead with 6 degrees of caster, when you turn the wheels you might have say 2 degree of camber. But if you had 7 degrees caster, when you turn the wheel it would have 2.5 degrees camber.

http://buildafastercar.com/tech/Dyna...in-Inclination.

Again, not saying one is more important, just that the fact being stated was the wrong way around, ie camber doesn't affect caster.

ULLLOSE

iTrader: (1)

You would be wrong. The shape of the lower control arm on the RX-8 makes it lose camber when you dial in any caster.

And again, if you are turning the wheel to the point that the caster gain is more than the camber you are doing it (driving) wrong.

edj

have your alignment guy dial in the minimum amount of caster he can in the front,
then dial in the most negative camber he can and then even out the caster.
you will still end up with 4.5+ degrees of caster.

burglar

You mean the full lock noob push? (Yes, that's me in the passenger seat attempting to instruct.)

TeamRX8

iTrader: (25)

That's not all you have backwards ....

https://www.rx8club.com/showpost.php...1&postcount=13

ganseg

iTrader: (5)

These comments on reducing caster apply to road courses too? This year my two events will be long, fast tracks (brainerd long course and road america - two turns at brainerd are taken at over 110 in my car and over 140 in some cars and bikes)