Author Topic: anyone done this setting pinion angle on caltracs  (Read 1618 times)

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hbstang

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anyone done this setting pinion angle on caltracs
« on: October 15, 2020, 04:53:06 PM »
64 fairlane with caltracs,and their split mono leafs,i was told to set between 2-4 degrees pinion angle to crank centerline.9 inch is not welded to perches yet,thats where i am at right now.any one done this?
anyone have any real world results?i have it set at 4.2 right now,and was told rear will want to change that on launch.

SSdynosaur

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Re: anyone done this setting pinion angle on caltracs
« Reply #1 on: October 16, 2020, 09:27:50 AM »
My recommendation is to call Calvert direct. The company offers free technical assistance for installation of their products, be they used or new. You will derive benefit of many installations vs. only one or two.

jayb

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Re: anyone done this setting pinion angle on caltracs
« Reply #2 on: October 16, 2020, 09:53:15 AM »
See the thread below for how I set the pinion angle. 

http://fepower.net/simplemachinesforum/index.php?topic=9305.0
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

XR7

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Re: anyone done this setting pinion angle on caltracs
« Reply #3 on: October 16, 2020, 04:39:13 PM »
When I did my new rear end housing, I used Calvert spring perches and welded them on to have a negative 3.5* compared to the output shaft of the transmission. On the old stock housing I had to use angled shims on the perches to drop the pinion down enough to work correctly. I would say if you are running a drag car -4 degrees is good, if more of a street car then -2. I have heard of some guys going to -6 or more, but that will kill your U-joints eventually.

Remember, the ground or the drive line angles mean nothing, measure with the driveshaft out, and it is the total number that counts, so if the trans is at -2 then the pinion should be -2 for -4 total. or if the trans is at 0 then the pinion should be -4. I used a digital angle finder with a magnet base, but the dial type work fine also. Under hard acceleration the rear pivots up 3-4 degrees so both shafts are parallel.

Put some preload on your caltrac bars, maybe just 1/3 to 1/2 turn, then adjust one or the other to make a straight launch if it goes to one side. If it goes to the right, put more preload on the right bar to straighten it out, etc.
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hbstang

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Re: anyone done this setting pinion angle on caltracs
« Reply #4 on: October 17, 2020, 12:47:14 PM »
thanks for the replies.i think i am ok where it is.trans is a glide so wont hit the tires as hard as a manual trans.i will also try to get that book on door slammers.

hbstang

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Re: anyone done this setting pinion angle on caltracs
« Reply #5 on: October 25, 2020, 12:40:43 PM »
i bought that book door slammers,found a nice one on epay for $20.on page 117 it states to set pinion angle from rear end to DRIVESHAFT,exactly the opposite what calvert told me to set it.he said the engine/trans centerline axis,not the driveshaft! i guess the book was written before caltracs became big,i will follow what they told me.