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alignment and suspension setup

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Old 10-01-07 | 09:30 PM
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alignment and suspension setup

Well I have my car, and sure its fun. But overall I believe I dont have a good knowledge of how to setup the suspension as far as in garage alignments, front camber adjustment, etc. Sure I can adjust my coilovers, and rear camber link. But I feel there is more I just need guidance on. Any recommendations would be great!
Old 10-01-07 | 11:53 PM
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Get a pyrometer and a stopwatch and tune camber from there. Generally speaking the reccomendation is to shoot for even tire temps. The front needs more camber than the rear. Something like 2-3 degrees front and 1-1.5 in the rear should be a decent starting point, but it'll be somewhat track dependant (lots of straight vs tight and twisty). Also this can affect the balance as adding camber should increase grip in the corners at the expense of straight line grip (accel and brake). The stopwatch will help tell you what's ideal in terms of speed, but that might not be the best if it wears out the inside edges twice as fast.

Toe out in front makes the car want to turn in at the expense of straight line stability and it'll further wear the inside edges of the tires. Tow out in the rear will make it want to come around more and it's generally advised to run toe in or zero toe at the most.
Old 10-02-07 | 08:57 AM
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After buying some suspension setup tools (camber gauge, toe plates, pyrometer, etc) and messing around I decided I would be better off letting experts setup my car. I found a pro team with a shop and now they do my setups. My lap times saw a huge improvement. You'll need the car corner weighted which requires expensive scales. I still do the wrench turning on the car but setup is left to those with the right equipment and much, much more experience. Setup is something easy to screwup and has a huge impact on your times. This is not like changing brakes, tranny or whatever.
Old 10-02-07 | 11:50 AM
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If you approach it with an analytical attitude and some background knowledge it's quite possible to get the setup at least very close to what's ideal. I help wrench on a GT3 BMW and through some suspension setup changes I've helped the driver set a new personal best time at his home track. I didn't have any previous experiance, but I knew the concepts. The experts weren't always so, they had to start out somewhere too.

The usual advice is: one change at a time, write EVERYTHING down, that way you can always go back to the original setup if you screw it all up.
Old 10-02-07 | 01:29 PM
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True and I would agree with what Black91N/a said but unless you are very experienced driver how do you know if the car is handling excellent, good or just okay? You need to know these things to make changes. That takes lots and lots and lots of track time. Is it sliding more than it should? Etc. Having a pro driver take my car out on the track and do my setups now has helped tremendously.

My car seemed fine to me before, I didn't know if it was at full potential with the setup I had done - all set according to the advice of fellow racers with like cars. The first time a pro driver took my car out, he spun out and said ... "this thing drives like a turd." Turns out he was right as my times have dropped significantly since making adjustments. I can't wait to see what his advice on some custom valved shocks and 50lbs more of spring will do.
Old 10-02-07 | 02:26 PM
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thanks guys for the information. I figure you can make all the hp, and have the best engine, but it wont do a thing without the suspension. The car at the moment doesnt feel as tossable as I would like. Maybe this is good for large track use, cause it seems pretty flat. But at a recent autox, the car just didnt like to turn, or had excessive oversteer. Here is a vid of the run

http://youtube.com/watch?v=HGpyfaZAICo
Old 10-02-07 | 06:46 PM
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Well there are a lot of variables. I'm hardly an expert, but you need to specify what spring rates you're running, what tire pressures, what your current alignment is, if you might have any worn bushings or balljoints, swaybars (or lack thereof), etc.

All of them can matter quite a lot.

Dave
Old 10-08-07 | 10:52 PM
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If you want to really understand suspention setup buy the book "how to make your car handle". by Fred Puhn and published by H.P. books. Its the best thing Ive seen out there. I have my dads copy from the seventies, and its still the very relevant, however they have come out with tons of revisions.

All and all suspention setup really has too many variables in it to really properlly troubleshoot on a forum.
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