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Discussion Starter #1
I checked my pinion angle it measured -5 deg. on the output/tailshaft and 0 deg. on the pinion yoke. Based on these readings calvert Racing's advise was to leave it where it was at.
This is a 66 Chevy II with front and mid plates and stock cross member. The 1 3/4" header tubes hit the shock towers and do not allow the motor to be lowered in the front. I think rasing the mid plate would cause the trans to hit the tunnel.
I was hoping to get some angle into the pinion to see if it helped the 60 foot time. Anyone had this problem or have any idea how to get the motor/trans level.
Thanks for reading, Craig
 

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In theory, you always want approximately 2 degrees differnet from parallel when driving. That would mean 5 degrees down on the tail shaft and 3 degrees up on the rear end yoke. It really depends on how much your axle will wrap on the springs. The axle wraps up on accelleration and down on decel. Your axle is wrapping up close to the ideal angle on acceleration. If calvert says this setup will work I'd leave it. They know the performance of their springs.

You're axle angle is alway changing slightly while driving. The trick is seting the angle that will work for most of your driving.
 

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Discussion Starter #3
This is strickley a drag car as far as ride usage goes. I am just curious if getting the engine/trans closer to level would allow me to shim some angle into the rearend. I would like to find out if that might help the short time any.
 

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This is strickley a drag car as far as ride usage goes. I am just curious if getting the engine/trans closer to level would allow me to shim some angle into the rearend. I would like to find out if that might help the short time any.
Being strickly a HP drag car, your rear will be very close to level going down the track

It you set it level sitting still, it will be off going down the track.

Edit: You are not looking for level; you are looking for parallel. If you engine is down 5 degrees, you are parallel when your rear is up 5 degrees.
 

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Discussion Starter #5
I understand what you are saying :yes: what I am wondering is would I be better off if my situation were reversed? Would it sixty better if the trans shaft was 0 deg. and the rearend was 5 degrees down. If it makes no difference I guess no need to worry with it. I just really think the car should go better than a 1.60 short time and be pulling the wheels some on take off.
 

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I don't go by what the "experts" say, I use what works for me. when I ran slapper bars I used 8° wedges to get the pinion nose down, regardless of what the other angles were. With my current Cal-Trac setup it wants at least 4° nose down or it won't hook. My car sits lower than stock so the driveshaft angle is less than stock, but I usually don't pay much attention to that angle; as long as the pinion nose is pointing down at least a few degrees.
 

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what bowtie said i had mine two degrees up and my car wouldnt hook at all im running a heidts 4 link so i went 4 degrees down and now it works. i even read the chassis book and what it says in there is pinion angle up will hit the tires harder and pinion angle down hits the tires softer. but sometimes what works on one persons car doesnt work on your car i say play with your pinion angle at the track experiment and see what works for you :yes: :D
 

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what bowtie said i had mine two degrees up and my car wouldnt hook at all im running a heidts 4 link so i went 4 degrees down and now it works. i even read the chassis book and what it says in there is pinion angle up will hit the tires harder and pinion angle down hits the tires softer. but sometimes what works on one persons car doesnt work on your car i say play with your pinion angle at the track experiment and see what works for you :yes: :D
X2. welll said. i would buy some shim plates and start playing with it. they sell them in 2* incraments. on any leaf spring car that i set up, no mater the traction aid i always found that they like at least 4* down on the yoke. sometimes more but to hook good never less. (in my findings, with cars ive owned or worked on) play with it and it will help you or hurt you, either way its always fun testing and tuning race cars!:yes:
 

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On my Son's car with slapper bars we are running the pinion angle equal but opposite to the the trans angle + an additional 4 degrees pointed down. With 1/2" snubber clearance the whole car lifts on launch.
 

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Discussion Starter #10
I think I am gonna see if I can get the engine/trans angle up a few degrees and add some shims to the rear and just see what happens.
 

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Shouldn't need to move anything but the rearend--make 1 change with some shims and see what happens. Moving the engine/trans around makes no sense...just a lot of work.
 

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Im assuming you guys aren't experiencing any driveshaft vibrations from these angle changes?
My car has all solid mounts, no interior, and 3-1/2" exhaust...EVERYTHING vibrates and rattles and hums!! On the Power Tour, the harmonic cycling, or droning, or whatever you want to call it, was noticeable. I don't let every little squeak or rattle make me nervous like some people; I just drive the crap out of it and if something ever breaks, I fix it. I rarely do maintenance, and my junk lasts far longer than it should.
 
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