Previous Thread
Next Thread
Print Thread
Pinion Angle using leaf springs #2731366
01/09/20 10:57 AM
01/09/20 10:57 AM
Joined: Aug 2006
Posts: 809
ar.
B
bobs69 Offline OP
super stock
bobs69  Offline OP
super stock
B

Joined: Aug 2006
Posts: 809
ar.
What pinion angle can I start with. 3100 pound car on slicks race car only. Thanks

Re: Pinion Angle using leaf springs [Re: bobs69] #2731370
01/09/20 11:14 AM
01/09/20 11:14 AM
Joined: Jan 2003
Posts: 4,707
Moved to N.E. Tennessee
GomangoCuda Offline
master
GomangoCuda  Offline
master

Joined: Jan 2003
Posts: 4,707
Moved to N.E. Tennessee
Is this with SS springs? 6deg down is the standard answer.

Any other aftermarket suspension like Caltracs etc go by what the manufacturer says. They should know.

But it is a little more complicated than that. Caution - it is more than just measuring the angle of the pinion.

You can push the search button on this site and punch in pinion angle. You will get over 150 hits. Beware many are very knowledgeable others not so much. Understanding and measuring pinion angle seems to be impossible for some.

Do-do storm in 5-4-3-2-1-

Last edited by GomangoCuda; 01/09/20 11:30 AM.

In theory, there is no difference between theory and practice. In practice, there is.
Re: Pinion Angle using leaf springs [Re: bobs69] #2731387
01/09/20 12:06 PM
01/09/20 12:06 PM
Joined: Jan 2007
Posts: 8,027
Mt Morris Michigan
mopar dave Online content
master
mopar dave  Online Content
master

Joined: Jan 2007
Posts: 8,027
Mt Morris Michigan
Here is a good tool to help you. https://spicerparts.com/calculators/driveline-operating-angle-calculator
Mine is at 2* with caltracs.

Re: Pinion Angle using leaf springs [Re: bobs69] #2731449
01/09/20 02:41 PM
01/09/20 02:41 PM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
C
Cab_Burge Offline
I Win
Cab_Burge  Offline
I Win
C

Joined: Aug 2003
Posts: 43,007
Bend,OR USA
Mopar use to have a chapter on pinion angles for drag racing in their old drag racers manuals, I drag raced a 1970 Hemi 4 speed car in NHRA stock for several years back in the mid 1970s, on your deal I would shoot for between 5 to 7 degrees nose down between the pinion shaft and drive line at the rear U joint on the ground with your body weight in the driver seat scope twocents
If it vibrates at all when you let off in high gear above 100 MPH decrease the angle until it doesn't vibrate or let you know it isn't happy scope
This angle is for SS leaf springs only with no bars or other traction aids using a stick tranny, automatic need less pinion angle to work well work


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Pinion Angle using leaf springs [Re: Cab_Burge] #2731562
01/09/20 08:14 PM
01/09/20 08:14 PM
Joined: Jan 2003
Posts: 5,788
Hamilton, Ontario Canada
Magnum Offline
master
Magnum  Offline
master

Joined: Jan 2003
Posts: 5,788
Hamilton, Ontario Canada
The advice of 7 deg is to compensate for weak leaf springs. This is a recipe for vibration. A perfect set up has matching front and rear angles. 7 deg in the front is not happening.

Set it for 2 to 3 nose down and work on controlling axle wrap.


69 Super Bee, 93 Mustang LX, 04 Allure Super
Re: Pinion Angle using leaf springs [Re: bobs69] #2731565
01/09/20 08:25 PM
01/09/20 08:25 PM
Joined: Jan 2003
Posts: 11,895
Benton, IL.
D
DaveRS23 Offline
Special needs idiot
DaveRS23  Offline
Special needs idiot
D

Joined: Jan 2003
Posts: 11,895
Benton, IL.
Have a smart phone or access to one? Here is a great app for them that measures not only the rear, but the drive shaft and tranny.

http://www.tremec.com/anexos/Literature/Driveline-Angle-Finder_Instructions.pdf


Master, again and still
Re: Pinion Angle using leaf springs [Re: DaveRS23] #2731876
01/10/20 05:31 PM
01/10/20 05:31 PM
Joined: Mar 2006
Posts: 9,791
MI, usa
dvw Offline
master
dvw  Offline
master

Joined: Mar 2006
Posts: 9,791
MI, usa
The bottom line is to have the trans output and pinion parallel under load. Depending on spring stiffness, Cal Track, amount of housing seperation I've found pinion 5 degrees down to the trans centerline to work well. Some combos may need a tweak +/-. Pay zero attention to actual drive shaft angle. Trans and pinion only.
Doug

Re: Pinion Angle using leaf springs [Re: dvw] #2731886
01/10/20 05:58 PM
01/10/20 05:58 PM
Joined: Dec 2005
Posts: 11,408
Fulton County, PA
C
CMcAllister Offline
Mr. Helpful
CMcAllister  Offline
Mr. Helpful
C

Joined: Dec 2005
Posts: 11,408
Fulton County, PA
Quote
Have a smart phone or access to one?


Yes, and I've fooled with it. Not accurate enough. Not nearly as good or as handy as a decent angle finder.

Quote
Pay zero attention to actual drive shaft angle. Trans and pinion only.


Really? Positive pinion angle - or operating angle where the pinion is nose up relative to the driveshaft centerline - is to be avoided. A leaf spring deal is likely to be a small tire with the rear housing in at or near stock ride height. Probably with the rear U-joint lower than the front joint. So you should be able to get the operating angles where they should be. A different situation from a big tire, back half type car with the engine/trans in at stock location.


If the results don't match the theory, change the theory.






Powered by UBB.threads™ PHP Forum Software 7.7.1