Aerosmith

I'm trying to learn more about chassis setup to help me improve primarily my launch and 60'. I have articles showing instant center with ladder bars and with 4 links, but I want to know where you draw the lines on the torque arm setup. I understand the LCA's are equiv to the lower bars on a 4 link. On the T/A do you draw the line with the lower bar, upper bar, or maybe from a point between the bars at the rear through the front mounting point or how?
I have a 9" and a Jegs short tunnel mounted adj T/A, 90/10 struts and the rear shocks are set on 70/30. The car is a 3rd gen and sits with a 4 degree rake(down in front), which is because of the taller tires in the rear and softer Moroso springs up front. It lifts in the rear a good amount when I launch and pretty much stays up there the whole run. I'm concerned that I'm losing power lifting the body rather than moving forward.
The car does mostly high 1.7x 60's with the best ever at 1.73. Best et has been 12.31@111 with a 1.77 60' on 29x9 slicks.This is a n/a 383 th350 with 3000 stall, small cam 226@.050 dur, 3600lb w/driver.
So basically I want to get it more neutral and need to know where to go with it. Any help is greatly appreciated. Here is a link to 2 TnT runs from a couple weeks ago, maybe they will help with evaluation. Click on video under the pic of my car:

http://www.myspace.com/130921237

Aerosmith

Wow, it's hard to believe that with all the guys here who race their cars, nobody knows the answer to this.

MADMAN

iTrader: (4)

Draw the line thru the lowers. Then draw lines thru both torque arm bars to the front mounting point.

Actually the rear is supposed to separate from the body.

Aerosmith

Thanks for the help, I thought that both tubes and the front mount would make sense but wasn't sure since the top tube bends and contacts the bottom before the front mount.

MADMAN

iTrader: (4)

You need to pretend the bend isnt there.

Aerosmith

Okay, now I know I'm on the right track. I just found a picture of my launch from 2 weeks ago on the track photographers' website and the left front tire is off the ground maybe about an inch, which I take as a positive sign it was hooking ok. I just don't know why it won't 60' any better than 1.7x. Thanks again madman for the info, I appreciate it.

n2ojunkie

To me that sounds like a tall tire for that hp. Sounds like its more or a race car than street so I would think its lighter than mine at 3700lb. I trap in the 110-111 range and make around 330 rwhp. Maybe a shorter tire or more gear would help your 60 more than anything else right now.

Thats just my .02c and I am not expert.

Aerosmith

The car weighed 3400 with no driver before I put on the 'glass hood and removed the front sway bar, and I weigh 230 so I'd say about 3600 to be close. It is a little tall of a tire. To be honest I got a killer deal on these tires and rims complete with only 5 runs on them so that's what I have for now. In the spring I'm planning some shorter slicks. Actually it's my daily driver.