I do a little welding on the side and I thought about making my own adjustable torque arm. From the looks of it I'm pretty sure I can make one rather easily. But I don't know much about pinion angle. How should one be adjusted for drag racing... Can some one explain it to me or refer me to site that explains it.

Positive pinion angle is when the nose of the rearend points to the ground. Imagine an imaginary v drawn through where the driveshaft and pinion shaft intersect. When the car launches, this levels out, plants the tires, and then returns to normal. Thirdgen f-bodies don't have enough positive pinion angle stock. The Random technologies adjustable arm allows for 4 degrees of negative pinion angle (do NOT go more than 4 degrees in any direction). When a car is launched hard, the force levels this out and both tires get planted hard. CHP did a drag test with this arm. On their 93 Trans AM, 60ft times dropped from 1.88 to 1.64 seconds after installation.




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82 Camaro:
350, Erson cam, ported heads, Crane Hi-6 ignition, Accel supercoil, Comp Cams 1.6:1 rocker arms, Turbo 350 tranny with 2500 stall.

ok you said a third gen didn't come out with enough positive angle stock. And the aftermarket allows for 4 degrees of negative angle, how would this help... I may be missunderstanding you.

is it 4 degrees from the rearend.....
aslo.....sphon make relocation brackets for a thirdgen car. This doesn't change pinion angle does it.... but if it doen't how does it help?
How would the combination of changing pinion angle and the relacation lca brackets work.
Or would this be too much.


[This message has been edited by Z-BOSS (edited March 27, 2001).]

You measure the angle from the rear-end. Imagine a horizontal line from the pinion shaft through the driveshaft. This is the hypoteneuse of your triangle. The pinion shaft is angled down 4 degrees down. I don't know about the effect of relocating the LCAs along with improving pinion angle, but it probably doesn't hurt. You might try posting on Spohn's board to get the answer to that question.

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82 Camaro:
350, Erson cam, ported heads, Crane Hi-6 ignition, Accel supercoil, Comp Cams 1.6:1 rocker arms, Turbo 350 tranny with 2500 stall.

You need to take 2 measurements with an angle finder. The third gen is easy to get the pinion angle with the torque arm mount built into the housing. Place and angle finder on the mount. Lets say you get 15 degrees. Now place the angle finder on the driveshaft. If it's also at 15 degrees then the pinion angle is zero. You want the pinion to point down a couple of degrees in relation to the driveshaft. The pinion angle is in no way in relation to the ground level.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
461 Big Block installed and ready for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley