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I just purchased an IT-7 that has an adjustable panhard bar. The person I bought it from was running Road Atlanta and set the front camber at 2.5° on the left and 1.5° on the right. The track that I am about to run regularly has a pretty equal mix of Right and Left turns, so I am thinking of setting the camber the same from side to side.
Any suggestions on setting the alignment would be greatly appreciated.
Most of us run pretty aggressive front camber. 2.5 on each side is not a bad place to start. Just a hair of toe in, Maybe an 1/8”. Less tow in is faster on the straights. You do not want toe out under braking or it gets unstable. If the front link bushing are replaced from stock with something stiffer you can run closer to 0 toe.
What Dick said, you dont want toe out at all in the brake zones.
Check the Idler arm and replace with the MOOG part that actually fixes the toe in/out difference that the stock Idler arm bushings have. Mazda Trix has the part number. Or Rock Auto.
2.5 is a great place to start, we ran Hoosiers at as much as 4.5 in the past. The 15 inch wheels dont need as much camber due to less sidewall deflection.
Good Luck,
Dan
Sounds good...how about caster?
Caster is, IMO, one of those highly theoretical things that, in the 1st gen, makes little performance difference. At least in the setting range I preferred.
As you increase camber, it will affect caster, and steering feel/self centering. (I'd have to look up/think hard to give your the mechanics of how/why that is)
Self centering steering is one of the joys of a rear drive car, and feel is a result. Steering feel will make 98% of us better drivers, because we will sense what the front tires are doing.
So, I adjusted my caster so that I liked how the car steered and felt.
yea, I know, not very scientific, but it seemed to work. Car was pretty quick that way.
So, my advice: knock the top of the struts back in the range of adjustment (assuming you have adjustable plates), but not all the way back (in the case of the Ground Control plates) but pretty close. The steering should build force as cornering forces build and then, when the tires begin to go past their maximum adhesion, the effort should become lighter...the tire is slipping. The steering wheel should unwind quickly when/if you were to let go of it when you are in a corner. Tweak the settign as needed.
Remember that all the settings are inter related, and adjusting caster will affect the others slightly. Adjusting camber will affect toe the most. Check your toe last.
(Another tip that saves time at the track. Measure the amount of change in toe that results from a 1/2 or full turn of the tie rod adjuster link. AND which direction causes the change. Write it down someplace. Wrap the adjuster with white tape and sharpie an arrow on it so you remember, and write the number down in your set up book. You have a set up book, right??)
Good info and the car came with at least some documentation which included a Rebco Chassis Setup Sheet (unfortunately no blank ones) and Pre-Race Checklist from when ISC Racing was maintaining and setting up the car back in 2005/2006.
Looks like one of the setup was:
Front: 2.5° camber, 2/32" toe out, with 375# coilover springs and running on Hoosier Street TD for a driver.
Rear: Panhard Bar and unknown spring rate.
Another entry has 1/32" toeout up front, but no other info.
This car also has a welded rear differential.