Pinion angle?

[Formulaboy95]

Got some new suspension goodies, one of them being a Random Technology Adjustable Torque Arm. Just a little bit confused on measuring the pinion angle. I bought a mechanical protractor from Home Depot, but not sure where to place it to get correct readings. Anyone done this before?

[Injuneer]

First put it on the driveshaft. Measure the angle. Then put it on the "flat" on the housing, under the pinion shaft. Measure the angle. The difference between the two angles should be -1 to -3deg (depending how much power you are putting down). To make sure you are calculating the "difference" correctly, the end result should be a "V" with the u-joint at the low point.

[Formulaboy95]

hmmmm... gonna get the Formula up on ramps and jack stands for the rear. I never really paid too much attention to the driveshaft/rear, so I am going to look for the flat spot.

[Kevin - Blown 95 TA]

If you use jack stands on the rear, put them under the axle. The suspension needs to be loaded equally. Actually, you should use the ramps on the rear. If you put the front on ramps and try to jack up the rear, it can roll. Magnetic angle finders are easier to use than protractors. And you want about 2 deg less angle (about 1 deg or so) on the street than for racing so you aren't wearing your u-joint all the time (unless you are street racing). The theory is that under power, the rear end will try to rotate up, and at that point you don't want any angle. On the street, when you are just cruising around, you don't want much angle either. So just keep in mind how you are going to be using the car. I used to set mine at the track, then chang it back after i was done racing. as you can see from my sig, I never got enough traction to really take advantage of the adjustment - my tires actually work better on the street, but I don't race there. I need slicks pretty bad.

[N20LT4Bird]

Originally posted by Kevin - Blown 95 TA
I need slicks pretty bad.

So you have the 12 bolt already, the slicks are a minor investment after that is done. What times are you hoping for on slicks?

[Kevin - Blown 95 TA]

NT0LT4bird -I was thinking 11.4 at least or maybe a little better. Hard to say, but my mph is pretty strong. Not sure if slicks would help the mph or hurt it a little bit. ET would definitely be better because I usually spin all the way thru 1st, even with a soft launch. I have handicapped myself with the big brakes & run the 17X275's up front and can't put skinnies up there, and I do not have an all out drag suspension, either. My car is a real compromise, but that keeps it very streetable. I probably won't buy the slicks, cause I don't have a cage anyway.

[N20LT4Bird]

Sounds about right kevin. Our MPH are pretty close and I am hoping for mid - high 11's after my rearend goes in.

At what point do you have to go with a cage?

[Kevin - Blown 95 TA]

<12.00 for NHRA and <11.5 IHRA. Verts are <13.0 (I believe) for NHRA and I am unsure about verts in the IHRA.

[Injuneer]

You need a 5-point roll bar, not a cage for NHRA:

Coupes/T-tops under 12.00
Convertibles under 14.00

You need a certified full cage (10-12 point) for all cars under 10.00-seconds, or over 135mph. Also need a competition driver's license.

Not sure about IHRA.

[fastTa]

http://www.milandragway.com/test/rules.htm