Loudmouth LS1

iTrader: (10)

I'm not sure exactly how to set the pinion angle or what exactly it should be at on my T/A, please help! I know it makes a diff what the angle should be for manual vs auto, so I need it for auto cuz I have a Turbo 400 in my Z! My angle was pretty good cuz I was cuttin 1.58's with less power, but before I went to the track the other night I noticed a loose nut on the torque arm that holds the adjuster from moving, so I tried setting up the angle, but definately didn't do it right, cuz all I was cuttin all night was 1.61's and the car has more power now, so I would think it would've 60'd better! It felt like it was dead hooking, just didn't feel like it was leaving as hard as it usually does!!! I have a magnetic angle finder, just not sure if i'm placing it in the correct spots and not sure what to do with the readings! Thanks for any help!

Coach 02 A3 Z/28

iTrader: (10)

Give Madman a call. This question is right up his alley.

Coach

Black Sunshine/ 00SS

iTrader: (1)

Instructions say to place angle finder on the driveshaft, write down the angle, then place on TQ arm mouting plate (where it bolts to rear), write down that measurement, & subtract. For example +3 on driveshaft, -7 on TQ arm, =-4.

I run -4, as do quite a few others here. You might want to start at -2 & work your way there. Make sure car is on all 4's. I did mine on an alignment rack, but I have done it also by putting the car on bricks under each wheel. Whatever works for you.

Pro Stock John

iTrader: (34)

-2.5 to start

FEAR THE LS1

iTrader: (1)

Hrmm that doesn't make sense... If you take the angle of the drive shaft +3 and the angle of the rear plate -7 and you are supposed to subtract them..

+3 - (-7) = +10 ?

or

-7 - (+3) = -10 ?

Was that just a bad use of an example?

I'm gunna measure my angles tonite, I installed my TA and set the angle eye. I'd be curious to see what my pinion angle really is.

Thx,
Lee

LS1x2

iTrader: (11)

I don't really see where pinion angle measured in relation to the DS has much to do with traction. Only the degree that the pinion itself faces would seem to matter. The more it points down the more traction you should get to an extent. Of course at the risk of breaking u-joints. Just my opinion.

Loudmouth LS1

iTrader: (10)

Anyone know exactly how to do it?

Steve Burger

iTrader: (33)

I used the driveshat and TA mounting plate method. Billingsly has the car now for roll bar installation and strange driveshaft. Jay said I had a positive pinion angle. He said to use the pinion yoke and the driveshaft. I hope he will explain this and show me when I pick the car up this weekend. If he does I will post what I learn.

Loudmouth LS1

iTrader: (10)

Please do, thanks!!!

MIGHTYMOUSE

iTrader: (59)

heres perspective. to have negative pinion angle of the driveshaft to the rear from the top of both would measure to to be less than a total of 180*

with positive angle they should measure more than 180* between them

to have -3* you would want 3 degrees less than perfectly flat(180) which is 177.

taner

iTrader: (6)

yes d.s and t.arm mtg plate is the proper way to do it.

Loudmouth LS1

iTrader: (10)

Yeah, I had emailed BMR and they sent me a reply yesterday to call them. So I called them when I got off of work today, and they explained to me exactly what to do, they were a great help, thanks BMR!!!!!! I was measuring from the flat spot on the bottom of the rearend, not on the actual bracket that the t/a bolts to the rear with, and I was doing the #'s wrong, you have to take the difference between the two #'s and you want the # on the rear mounting plate to be - and a bigger number than the # on the driveshaft. Like right now my driveshaft angle is showing +2.5 and my torque arm mounting plate angle is showing -4, so it's a -1.5 pinion angle.

One ? though. I set the pinion angle to -2.5 at first and there was a ton of vibration and noise from the tires, so I backed it off to -2, and it got better but was still a lot (sounded like the damn u-joint was just gonna snap), so I then backed it off to -1.5 and it's perfect, no vibration or noise from the tires. Well, my ? is, should I start going back more aggressive a couple turns at a time till the vibration and noise comes back and then back it off one turn so I get the most aggressive angle I can get w/o ruining the u-joint? Also, if it's vibrating and making noise like that and all, is it hurting traction b/c it's set over aggressive, or is it just not good to run it like that on the street, like should I put it back up to -2 or -2.5 when i'm at the track? Let me know what you guys think, thanks!!!

Hardtop

iTrader: (3)

I have played with the pinion angle on my car a bunch, and it seems to do best at -2.5. I tried -4 and didn't get any unusual noises or vibrations. I run -2.5 on the street and track.

Bruce

raith76

I'm setting up my ta as well, and I have a question to ask pertaining to this. Where do you take the angle measurement off of the d.s. or does it matter?

Steve Burger

iTrader: (33)

Here is how it was explained to me. Get the angle on the DS as close to the U Joint as possible. Then get the angle off of the flat spot on the Pinion yoke. I was told the the TA mounting bracket is not as accurate as the pinion yoke. The TA mounting bracket may not be flat or in line with the pinion. From there do the math.

Just what I was told.

Big Rick

iTrader: (1)

The driveshaft is actually -3 also. Not positive. It's either (-)(-) or (0)(0) or (+)(+). There is no way to have a (+)(-). Using the driveshaft and pinion is the correct way. Just measuring the pinion is a no no. In a real world like dragster pinion angle and driveline angle are 0. There is no way for it to change or flex since the chasis is solid back there. A car flexes when it launches, that's why negative pinion angle is set, it actually moves towards zero when launching. Positive pinion angle just gets worse on launch and unloads the tires. Anything more then 4 degres on the pinion angle is bad, it's up U joints quickly. If your car requires that much pinion angle to 60' then your chasis sucks and flexes to much.

White Fire'99

iTrader: (15)

best and only proper way to do it......

http://www.rosslertrans.com/Tips/Pinon.htm

2QuickZ's

I may be wrong, but I'm pretty sure you could have a (+) and a (-). Anyway, lets take the + and - out of the equation to make it easier. Maybe I'm thinking about this the wrong way, but 180* (straight line) is what they call 0* meaning the pinion and driveshaft are inline. Using the example above would give you a pinion angle of 184.5* (what they are referring to as -4.5*) and driveshaft angle of 176.5* (or +2.5*). That should give you 184.5 - 176.5 = 6.5*. In this example, the 6.5* would be negative because if you drew a V shape representing the pinion and driveshaft, the tip would point toward the ground. If the V points toward the floor pan, the angle would be positive. A -6.5* pinion angle would explain why his U-joint sounds like it is about to be ripped out.

Like I said, I may be totally wrong. That is just my rambling geometric rationalization. I have the BMR T/A on my car as well and I still am not sure what it's set at because the example in the instructions didn't make any sense.

Big Rick

iTrader: (1)

Well it just depends on the way you look at it. But you comparing the angle in relation to the opposite side. When you're at 0* Your driveshaft and pinion will be totally in a straight line. But when you go to negative pinion angle, both the driveshaft and pinion will be negative (both facing down towards the ground). When there is a positive pinion angle the driveshaft and and pinion will both face up. If you were to use a angle finder and you did both readings on the same side of the car, yes you would get a reading of one positive and one negative, that's where people get the mix up of positive and negative. Take the reading from opposite sides of the car, then you will get a (-)(-) or (+)(+) reading. When you take readings form the same side of the car your first would be a relation of pinion and driveshaft, when you take the reading on the driveshaft on the same side of the car as you did on the pinion you'd get a angle of driveshaft vs drivetrain. It might be hard to understand, kinda of hard to explain. But it's very easy to do. I always take the measurement from the same side of the car, just remember the one reading on the driveshaft is actually (-) not positive that it shows.

SMOKIN01TA

iTrader: (10)

mine cam out with a + and a - when i did my bmr. you measure it from the plate on the bottom of the rear end housing, and the drive shaft. mine is set at -3. i believe the measurements were like +3 and -6
autos are set at -2 to -4 i believe.