i'm going to be making an appointment for a custom alignment sometime next week. i was just curious if the specs i have are going to be good. i do the occasional auto-x, but my car is primarily a street car. i do drive it pretty hard on backroads and drag race at my local 1/8th mile track. i was wanting something that'd work well for all, but primarily handling. this is what i had so far:

front: 1.2*neg camber, 1/32 toe-in
rear: .5*neg camber, 0 toe

i'm currently runnings 18x9 and 18x10 with 255/35 and 285/30

i know there's a ton of suspension gurus on here and it's not something i'd like to screw up. i'd appreciate the help fellas

 

I'm no suspension guru, but I suspect that you would want a little more negative camber in the rear. I am currently running about 1.25 negative on stock rims with 245/50's. The car seems pretty neutral. Like you, I see an occasional autocross, and some "fun" street driving. Your other settings look good to me.

 

larger wheels with less sidwall tend to need less negative camber to get the job done.

does anyone else have any ideas? i know there's a ton of suspension gurus on here

 

You might actually want toe out on the front to help it track straighter, toe-in rear helps keep the rear following the front, you'll want 6 degrees of caster or so. for the toe in/out 1/32 to 1/16th, you don't really want to go more than 1/16th.

Alignment and suspension settings sort of go together at least on the camber piece (sway bar especially); also what type of tires and tire pressure you're running. A streetable setting would be somewhere between -0.2 and -1.2 degrees front and rear.

Another FD that autocrosses out here is runing JIC FLT2 coil-over with -2.2 front and -3.0 degrees rear camber. I think he's running 1/16th toe. He also street drives this car though I'm not aware of what its doing to his tire wear (I think he drifts some on his street tires so chances are the alignment wear may not matter too much to him).

 

spoolin,

you are pretty close as to settings...

i agree w adam c that you should dial in more rear neg camber. i like 1.2 neg front and rear for a combo of street and moderate track performance. i say moderate as the car will definitely run faster on the track w more camber but will chew up tires on the street. i set camber at the track w a pyrometer.

as to toe....
you need just enough so the wheels aren't running straight as they will hunt. 1/16 would be fine. ditto in the rear.

caster... should be equal left and right and be modest. caster jacks weight in a turn so you want as little as is comfortable. (don't believe caster screws up a car in turns? park your car. turn the wheel full lock right and left. notice how one fender dips and the other rises... it is all caster. with the ride height change comes weight shift)

finally, make certain that the rear thrust angle is zero degrees.

run no more than 30 psi front and 28 rear cold tire pressure.

BTW, i run the same size wheels and tires so i know these settings will work for you.

howard coleman

 

so 1.2* neg camber front and rear, with 1/32 toe out up front and 1/32 toe in in the back. what kind of caster should i have them set it to? i'm just not a suspension guru, just looking for a good, modest setup

 

agreed. Both left and right wheels must have the same castor angle. However depending on what type of racing you are doing a greater castor angle can be used effectively. Running 7 degrees or more castor angle for autox competition is valid since the car never really stays in steady state cornering for long extended periods of time unlike road racing or solo1. Each corner of a autox course is quick and sharp requiring quite a bit more steering angle then in road circuits, so having as much dynamic camber as possible is advantageouus.

Castor increases your camber angle as a function of your steering angle. The weight shift the car is less important since the car is still in transient state when you are twisting the steering wheel trying to make the transition from left to right or full throttle to super slow speeds to make the hairpin turn.

I have no idea how much is enough or how little is correct... it is all a matter of test and tune and id on't drive a FD.

 

I have a 94 PEP with stock suspension. At my recent alignment, the technician (who I have dealt with for over 20 years) told me that he was not able to get a full 6 degrees of caster in the front when setting the camber at 1.2* negative. He was able to get about 5.7* maximum. I think that the lower cars, including the stock 93's, are able to reach the desired combination more easily.