I am about to start on my flip conversion in the rear. I wanted to confirm a few questions before I get started. I am going with weld on perches, and caltrac plates with the 1" offset hole predrilled.

1. I have seen/been told to drill the perches 11/16" to 3/4" off from center of the predrilled perch hole. should i go 1" like the caltracs are offset?

2. I have also found a few places that talk about pinion angle, but nothing solid. what did you guys set your pinion angle too before you welded it down? 2* negitive/down?

remember i am a RCSB. i think pinion angle was one of the factors why I broke the driveshaft at the track 2 fridays ago.

thanks guys

 

bump.....

 

nobody.......dont make me PM you!

 

found the info I was looking for.......thanks

 

i will reply.... im not sure how much adjustment you have with the heim joints on the caltracs. i would go 1" like the caltrac plates, so you have the correct amount of adjustability

 

well i guess im about three hours late... lol

 

I was told by an old racer that you want your pinion angle to be 4 to 5 degrees down with leaf springs. I've also heard other truckers say that 3 degrees down is the sweet spot. You say you broke your driveshaft? Did you have a hard shudder/shake feeling on your launch? That is what mine was doing. I checked my pinion angle and was about 1 to 2 degrees up. I cranked the caltracs to 0 degrees but think i'll put more shims in and try to fix it before I run again.

 

i did weld on perches too. and cut out some new flip kit plates on the cnc plasma. my pinion angle is set at-4 when i get around to building another set of caltracs im doin to fiddle with the adjusting. ive ben told you dont want them tight/binding on the leafs

 

no not on the launch, all above 90mph. i ordered a driveline angle tool from kent moore, and I will get it right about 3-4 negitive, and weld it in. I can adjust the caltracs for more. also relocated the passenger shock to the back for a better drag setup.

 

You do not want your cal tracs to dictate your pinion angle. This will give you way too much preload on the spring and un-needed stress on the whole system. Get your angle right by either shimming or adjusting your perches accordingly. If your caltracs are properly adjusted the roller will barely touch the top of the leaf on one side, and about 1/16" gap between the roller and leaf on the other... You can adjust them from there for best results but do not tighten them so much it affects your pinion angle.