Pinion Angle
04-13-2007, 09:44 PM
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Pinion Angle Ok guys, I took my torque arm off today to change a few things and ended up messing up my pinion angle. I tried to set it back but it doesn't feel right driving, lots of vibrations. It felt perfect before and I set it to -3.5 as per UMI's instructions over the phone. But for the life of me I can't remember how to do it. I thought I had it set right but here, I drew some rough sketchs in MSPAINT. Do I have this right if I want it at -3.5 or am I way off? I need to get this fixed tomorrow if it's off because the track is open tomorrow night and I don't want to screw up my new $400 driveshaft. This is an M6.
I took my measurements on the crank pulley and then on the torque arm mount on the rear end. I have the UMI tunnel mounted adjustable torque arm, and a moser 9" rear end.
Those are the current settings that don't really feel right. Is this -3.5 or +3.5? The pinion angle finder doesn't indicate negative or positive on either side.
I took my measurements on the crank pulley and then on the torque arm mount on the rear end. I have the UMI tunnel mounted adjustable torque arm, and a moser 9" rear end.
Those are the current settings that don't really feel right. Is this -3.5 or +3.5? The pinion angle finder doesn't indicate negative or positive on either side.
04-13-2007, 09:55 PM
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is your car lowered? if it isnt -3.5 is WAY to much of an angle.
if it is, it is still to much, if you are doing pure track i would go -3.0 degrees.
if it is a street \ odd time track use. go -2.0 degrees. that is what im going with, im getting my ford 9" with same combo as you installed right now.
im not sure what side of the dial you want it to be on. but i wouldnt go that much.
p.s. outa curiousity, how did you like going from the stocker to the 9" with 4.11's? results at the track?
if it is, it is still to much, if you are doing pure track i would go -3.0 degrees.
if it is a street \ odd time track use. go -2.0 degrees. that is what im going with, im getting my ford 9" with same combo as you installed right now.
im not sure what side of the dial you want it to be on. but i wouldnt go that much.
p.s. outa curiousity, how did you like going from the stocker to the 9" with 4.11's? results at the track?
04-13-2007, 10:02 PM
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I am pretty sure I was at -3.5* before and I loved it. No vibrations and it hooked. It was at -3* with me sitting in the car and -3.5* with me out of the car. I just want to find out if i'm at -3.5 or +3.5 right now or if there is even a difference?
On the rear, I never even got a chance to race my car with the 10bolt, the rearend went out a month after I bought the car and I went straight to the 9". I'll tell you this though, it gives you a huge peace of mind knowing you don't have to worry about breaking the rear end. I've pulled 1.6 60's so far at the track, launching off the limiter. It's hella fun
You'll be happy with the 4.11's though, its the perfect gear choice for a DD/occasional strip car. I still get 20-24mpg on the highway.
On the rear, I never even got a chance to race my car with the 10bolt, the rearend went out a month after I bought the car and I went straight to the 9". I'll tell you this though, it gives you a huge peace of mind knowing you don't have to worry about breaking the rear end. I've pulled 1.6 60's so far at the track, launching off the limiter. It's hella fun
You'll be happy with the 4.11's though, its the perfect gear choice for a DD/occasional strip car. I still get 20-24mpg on the highway.
04-13-2007, 10:14 PM
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yea, im so sick of slipping my clutch and feathering the throttle, i got drag radials now too. i had a god damn silverado beat me off the line last year. road was a little dusty, and shitty tires. i couldnt punch it till 85 km\h lol.
(wasnt a serious race obviously my buddy was just teasing me cuz i bet him he would beat me off the line)
(wasnt a serious race obviously my buddy was just teasing me cuz i bet him he would beat me off the line)
04-13-2007, 10:38 PM
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Ok after some searchin I found this on carcraft which is exactly what I wanted. So I do have it at -3.5 so I need to change my angle a bit so it is less harsh. I'll post this up just in case anyone else has this issue.
04-14-2007, 01:44 AM
#7
why are you measuring the crank pulley? to my knowledge, you only need to measure the angle of the driveshaft and the angle of the t/a mount....the difference between those should be 2 or 2.5 degrees.
you can measure the angle of the crank pulley if your driveshaft is exactly straight with the crank....which it is not going to be.
i dont understand what the reason is for measuring the crank pulley...
you can measure the angle of the crank pulley if your driveshaft is exactly straight with the crank....which it is not going to be.
i dont understand what the reason is for measuring the crank pulley...
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04-14-2007, 02:19 AM
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Driveshaft is aluminum and hard to get a reading from. You can either use a driveshaft measurement/transmission/crank measurement. Should all be the same. UMI said to use tranny, everything i've ran across said use crank pulley.
04-14-2007, 04:24 PM
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The crank pulley isn't a bad idea. I've had the best luck with only about 2* of pinion angle. Any more than that, and I start to get some bad vibes. Also, pinion angle is not going to affect your traction or make you hook better as you put it. Having that shorter TA will, but pinion angle won't. Set it to where your car doesn't vibrate and to where it's down somewhere around the 2* mark.
Ben T.
Ben T.
04-14-2007, 04:39 PM
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Here's some supplemental reading;
http://www.2quicknovas.com/happypinions.html
http://www.hotrodsusa.com/wordpress/?p=11
I've personally found that on a car with a good aftermarket adjustable torque arm having the pinion down between 1-2 will work well. This will limit the amount of vibration you get and you'll still get great traction (best you can with the rest of your setup).
Ben T.
http://www.2quicknovas.com/happypinions.html
http://www.hotrodsusa.com/wordpress/?p=11
I've personally found that on a car with a good aftermarket adjustable torque arm having the pinion down between 1-2 will work well. This will limit the amount of vibration you get and you'll still get great traction (best you can with the rest of your setup).
Ben T.
04-14-2007, 05:42 PM
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If you have leave springs that flex a lot then correct for that with a lot of pinion angle. If you have better than stock control arms and a heavy duty torque arm, your rear really isn't going to wrap around that much. I'm completely comfortable with 1.5* of pinion angle- the same that Jeb was saying.
Ben T.
Ben T.
