Pinion Angles and IRS rear suspension Q

[orphancars]

Quick question on driveline angles as they relate to IRS suspensions....

Most of the articles I have read say to keep the angle of the rear and the angle of the engine/trans equal and opposite. Question that I have is does that also hold true when using an independent rear?

I'm putting a C4 IRS in a custom chassis along with an LT4/T56.

Also -- does anyone have any info on what angle is best? I'm setting up the rear to have a max angle of +3 degrees "up", but will probably insert shims to run approx. 2 degrees.

Opinions? Help??


thx!

-jeff d
Fort Worth, TX

[paul67]

Yes, run the engine flat not angeled down like a carbed engine, if oil pan hits cross member make sure its out of a camaro if not you will need oil pan from a camaro as they are shallower i think they are on the LT1

[big gear head]

The angle of the crangshaft is suppose to be the same as the pinion angle when under power. With a solid axle you need to give the pinion a slight down angle in the front so that the angle will be the same when torque is applied to the rear end and the suspension allows the pinion to rise a little. With the IRS you can mount the center with the angle the same as the crankshaft because there should be no change in the angle when power is applied.
http://www.iedls.com/ptsetup.html

[orphancars]

Thanks Big Gear Head! That is exactly what I was looking for!!!


-jeff d

[ProdigyCustoms]

I use a 1/2 degree negative so the U joints work

[orphancars]

Frank,

Only 1/2 deg? Any issues with driveline life and/or noise/vibration? Seems like that's a little on the low side from most everything I have read..........just looking for data points before I lock everything in place.

thx!

-jeff d

[ProdigyCustoms]

The straighter you run it, the less loss you will have. but as i said, you need to work the U Joints a tiny bit. No vibration sissues at a half. A half to 1 is where we run a lot of rear, including live axles.