Pinion Angle?

CDN5.0

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Just a quick question: I'm having the ring and pinion replaced with all new bearings and seals as well. It's a 14 Track Pack car, sticking with the 3.73's in the Torsten diff. I've installed the Whiteline Suspension kit which lowered it about 1 3/4 inches, BMR adjustable motor mounts to drop the engine 1/2 inch and just installed the FRPP 3.5 inch aluminum one piece DS.
What is the correct pinion angle I should tell the Race shop to set the rear at after they finish the gear install?
TIA
Scott
 

MG0h3

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On DS with a single ujoint up front and one in back, you want the pinion pointed up the same amount as the trans points down.

Most hardware stores have a magnetic angle finder.

You’d check degrees on the on the tail shaft of the trans or anywhere that is flat. Record degrees.

Then place it on the pinion and have it angled up the same amount as your down angle up front.

You can’t always get the pinion printed up enough but if you dropped the engine/trans you’ll probably hav an easier time.


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CDN5.0

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Ok so as close to the same angle as the transmission then, thanks my Man - it's a respected race shop so I assume they have the equipment to measure properly - but I'll definitely ask.
Thanks again
Scott
 

03CRUSHER

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Baselinesuspensions.com

Learned a ton reading everything on this site. Basically depends on the how rigid your control arm bushing material is. I.e., rubber is softest, heim joints are hardest. The stiffer this connection, the closer you will be to 0*
 

MG0h3

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Ok so as close to the same angle as the transmission then, thanks my Man - it's a respected race shop so I assume they have the equipment to measure properly - but I'll definitely ask.
Thanks again
Scott

Same but opposite. Pinion up angle should match trans down angle. They cancel each other out.


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Norm Peterson

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Pinion up angle should match trans down angle. They cancel each other out.
That's the driveshaft geometry you want under max or near-max acceleration.

You need the pinion angle to not match the transmission down-angle at rest, so that under acceleration when the control arm bushings compress under load the angles move toward matching.


Norm
 

4VFTW

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-3-3.5 for rubber bushings
-2 degrees for poly bushings.
-1 for spherical joints

.... is a good starting point
 

MG0h3

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That's the driveshaft geometry you want under max or near-max acceleration.

You need the pinion angle to not match the transmission down-angle at rest, so that under acceleration when the control arm bushings compress under load the angles move toward matching.


Norm

Good point

I’m in Delrin. Little to no deflection


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