Olitho said:
What are the alignment specs you T1 drivers are using for track only applications of your car:
For Hoosiers?
For Kumhos?
Thanks,
Olitho
:usa: :usa: :usa:
Oli,
There is not one right answer to this question, and if there was, I'm not sure if any of us T1 guys would share it online... :lol:
The answer is dependent on several things including, the track, the tire make and size, driver ability and preference, suspension components, etc.
More specific thoughts:
- Track. I optimize my alignment for each track. Early last year I bought scales, laser level, camber/caster plates, toe plates and taught myself how to align my car. I don't use the same alignment at any track. CW tracks are different from CCW tracks. Fast tracks are different from slow tracks.
- Tires. In SCCA T1 we are allowed to run 17x10 front and 17x11 rear wheels with either 275/40-17 front and 315/35-17 rear, or 315/35-17 all around, but we can go +/- 20mm on any of the above to a max of 315 width... meaning there are a lot of tire options. 275 fronts don't respond the same as 315 fronts.
- Driver. Some drivers like a car that has lots of static understeer ("tight" for circle track terminology), others like a car with some oversteer ("loose").
- Suspension. The lower the car is, the more negative camber you can get. Without T1 leaf springs, you likely won't be able to get as much negative camber as a T1 car. Additionally, the camber plates you use will impact camber in a big way. Many T1 drivers use the GM Performance Parts T1 camber plates which give max negative camber with no adjustment. Others just use the stock concentric bolts and get less camber, but adjustible. Not legal in T1, but the Hardbar camber plates are like the T1 camber plates but available in many different camber settings other than just max. A very nice product.
What you really need to do is set your alignment and go drive on it and take tire temps. Learn to read the tire temps and see what the tire is telling you. Ideally, the inside, center and outside of the tire should be within 20 degrees of each other. When taking tire temps you shouldn't do a cool down lap, and minimize the time in pit lane. You want a snapshot of the tire temp on the track and a long trip down pit lane with lots of negative camber will heat the inside and bias the results. If outside is too hot, increase negative camber. I outside is too cold, lower camber. If center is too low, try a higher pressure.
All that said, here is a rough starting point not knowing what leaf springs you have, whether your car is lowered, and assuming you have R compound tires and assuming you want a track vice auto-x alignment:
Front:
- Camber: Max negative (T1 camber plates will give about -3.0 on a T1 suspension as a data point for you), matched side to side
- Caster: Max positive, matched side to side
- Toe: Very slightly out
Rear:
- Camber: -1.0 to -1.5, matched side to side (T1 plate will give about -1.5 on my LR, but more on my RR)
- Toe: -1/8 to -1/4" in
Hope that gives you something to start with. :cheers: