I have a UMI body mount TA and I was wondering what I should set the PA at. In the instructions it says to set it at 0 degrees. The car has a TH-400 with drag shocks and all tubular suspension. Also what would be the best way to set it, I bought an angle finder from Home Depot to use.

 

Set the car at ride height. Set your angle finder on the pinion yoke and set the pinion 2 degrees down.

 

The car is at ride height right now. So do I leave the angle finder on the drive shaft then move the TA until the angle finder reads -2?

 

I did a search when i put mine in and found too many different ways to set it. The way i did mine was i put the angle finder on the face of my crank pully to see the angle og my motor. Then put the angle finder on the bottom part of the TA (big flat piece the bolts go trough) and find that angle. Then find the differance of the 2 and thats your pinion angle. I got mine aet at -2deg. Best part of that set up is the car doesnt need to be level because no matter where your car is at, the 2 mounted parts on the car will always be the same.

 

Pinion angle is a reference from the pinion to the ground. The driveshaft and crank shaft is irrelevant to pinion angle. The only time the driveshaft comes into play is "driveline" angle.

 

well thats where too much info comes into factor. Hummm... can you explain a little more? Im under the asumption that you want your driveshaft at 0 deg. when WOT.

 

You are correct the pinion is going to try to roll up and be parallel to the track. This will cause the load to be placed on the suspension and lift the car and plant the rearend. The driveshaft etc is irrelevant because it can be mounted higher or lower than the pinion .

 

Guys, just listen to MadMan. He is the "Man" when it comes to suspension and putting a car on its rear bumper. He knows his ****!!!!

David

 

So how do I need to go about setting the angle?

 

Set the car at ride height. Set your angle finder on the pinion yoke and set the pinion 2 degrees down.

 

Madman , shouldn't you zero the angle finder? Where is the "zero" or neutral point? Here is what I am after...if the Tq Arm was put in with "X" degrees down up or doesn't matter really...how do you get the rear to Parallel then go 2* neg or down?


I was gonna ask you this yesterday and it slipped my mind.

David

 

The adjuster on the torque arm sets pinion angle. Moving the arm up or down changes instant center. The pinion is your 90 degree off the ground so if you set the pinion to 88 degrees down then you are at 2 degrees.

 

So MADMAN, i set my pinion -2 deg. so under WOT my pinion is gonna be parallel to the ground? If so i get that point. Now on my specific car i have poly motor/trans mounts. In turn raised up my motor/trans a tad. So what if that makes my driveline angle in a bind? Wouldnt i start tearing up my u-joints?

 

I havent seen a drag car get in a bind from poly mounts. Also if your suspension is stiff enough the pinion will never get to zero.

 

Put 28" tires on the back, 24's on the front, instant -2 PA. lol

 

thats what i got now, lol. So then i guess im crawlin back under there and gettin it set up again, thanks madman!! lol. Any other words of wisdom??

 

Wolfe has some good diagrams for reference. see www.wolferacecraft.com/pinionangle.aspx

 

so madman, when you set the pinion -2* from the ground why/what does that do to the suspension. Im gonna take a wack at it and say it plants the tires good but how/why? Im gonna set it up that way but wanna know why for personial referance. thanks man!

 

When the power comes on the rear end tries to do a backflip.
By setting your PA negative you are counter acting the twisting motion.

 

Which hole would be good to start out on with the instant center? With a Madman T/A. Street Vs. Track?