setting pinion angle

[bodycount]

Trying to help a buddy with a Malibu set up his car for the quarter mile. He has double adjustable uppers. Is that enough to set pinion angle or are adjustable lowers really necessary?

[craggar]

Yes the double adjustable uppers are all you need for doing the pinion angle. Single adjustables are all you really need but you need to take one end off to do it with them.

[bodycount]

Thanks, but wouldn't adjustable lowers help from having the driveshaft pushed too far into the trans? Or is this not a real concern.

[dentmasters01]

to extend this thread a little more........how do you measure to set the pinion angle?

[craggar]

Yes, most aftermarket lowers are adjustable on one end only. You should only have to adjust them once to get the diff in the right spot.
Double adjustables are nice on the lowers just just so you don't have to drop them to make changes when doing the intial setup.

[craggar]

Originally Posted by dentmasters01

to extend this thread a little more........how do you measure to set the pinion angle?

Here you go.


Pinion Angle

[John Wilde]

The amount of - pinion angle in your set up depends on your bushing and end type. A suspension with rod ends and spherical bushings will have no deflection so you can set it to -2*. With Urethane you should give it a little more ~ -4-6*.
This allows you to keep a - angle even with the deflection you will get.

[bodycount]

Originally Posted by John Wilde

The amount of - pinion angle in your set up depends on your bushing and end type. A suspension with rod ends and spherical bushings will have no deflection so you can set it to -2*. With Urethane you should give it a little more ~ -4-6*.
This allows you to keep a - angle even with the deflection you will get.

That is good info, I use to run with -6 deg pinion angle on my Mustang and it would just eat u-joints. I got lucky that I didnt chuck a driveshaft.

[John Wilde]

Originally Posted by bodycount

That is good info, I use to run with -6 deg pinion angle on my Mustang and it would just eat u-joints. I got lucky that I didnt chuck a driveshaft.

I personally don't like more than -4* but I don't think that is the general consensus so I did not post that.

[dentmasters01]

cool thanks for the link and info. Just set it to -3 deg. BG will be the first pass since the gnx susp. was removed and new set up installed.....Can't wait to see how it works !

[craggar]

Originally Posted by John Wilde

I personally don't like more than -4* but I don't think that is the general consensus so I did not post that.

I agree anything more then 4 is too much.

I just got out to the track with N/A GN and ran mid 10's with mid 1.4's 60'. My P/A is at 2.5 down. I have all TRZ with the sperical uppers. The only traction issue I have is the tire spinning on the rim. I don't want rim screws so I'm going to try the hitac on the beads for the next race when I use the nitrous.

[dentmasters01]

Just got back from BG. Set my pinion angle to about -3.5. All I can say is WOW !! The BEST 60 ft time before with the gnx susp. was a 1.62. with the new susp, 1.60, 1.53, 1.50. Felt awesome ! now I can try and leave harder and get in those 1.40's. Oh yea, all this is on street tires !!

thanks for the pinion angle info. !

[craggar]

Originally Posted by dentmasters01

Just got back from BG. Set my pinion angle to about -3.5. All I can say is WOW !! The BEST 60 ft time before with the gnx susp. was a 1.62. with the new susp, 1.60, 1.53, 1.50. Felt awesome ! now I can try and leave harder and get in those 1.40's. Oh yea, all this is on street tires !!

thanks for the pinion angle info. !

That's a big improvement. I may try a little more in mine just to see what it does. Seems like these cars like it somewhere around -4.

[John Wilde]

Originally Posted by dentmasters01

Just got back from BG. Set my pinion angle to about -3.5. All I can say is WOW !! The BEST 60 ft time before with the gnx susp. was a 1.62. with the new susp, 1.60, 1.53, 1.50. Felt awesome ! now I can try and leave harder and get in those 1.40's. Oh yea, all this is on street tires !!

thanks for the pinion angle info. !

Congratulations on your new best.
Please post more when you can.

[Lynn D. Brown]

I just reset my pinion for -2°, but it was on my TTA. There I have an adjustable Spohn traction bar from the rear to the trans and U can do the adjustment on the bar.