Driveline Angle

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Originally Posted by deuce4papa

.....And driveline vibration can drive a guy nuts trying to correct! So many variables to deal with from engine balance, torque converter, etc. right on back. If Roger can modify tunnel for later adjustments, that would help in case he does have a vibration to deal with.

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Deuce, this is probably the best advice, regardless what anyone believes about the various driveline angles for a street/cruise vehicle. My plan had been to see how much I can raise the tranny to decrease my angle without any more surgery, but I think now that the best approach is probably to get out the cutoff wheel and die grinder and chop the tunnel off, add some clearance, and have flexibility to deal with any problem later. I think I'll probably adjust the angles a bit anyway, just to take some of the bind out of the coilover mounts, keeping the angles matched as I can based on inclinometer accuracy.

Roger, have you read this? Lots of good info here.

Mike

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Originally Posted by rspears

Dave and TooFast,
I would make a guess that in either of the applications cited you would never even realize that there is a driveline harmonic :LOL: Launching for a 1/4 mile pass and banging gears, or tearing around the dirt oval with angles going everywhere are about as far away from a steady state cruise down the interstate as one can get, and I believe that is where the harmonic vibrations come into play. Sure, I want the thing to hook up on an occasional launch, but I'm much more concerned with a smooth ride on the street and highway, plus long term reliability - changing u-joints in the AutoZone parking lot on a car sitting 4 or 5 inches off the ground, chasing a driveline shake is not a good trip highlight! Your racing applications point out that the setup is not going to break u-joints, and I agree 100%. This is a street/cruise question to me, and one where the high speed NASCAR experience on asphalt may provide some insights, but drags and dirt tracking are probably not really relevant. Just my opinion, and I may be wrong. Thanks for the input, anyway. Everything goes into the decision hopper.

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Guess i just have to run it wide open all the time if i am off a degree... Thats more fun anyways.

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Originally Posted by Mike52

Roger, have you read this? Lots of good info here.

Mike

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Mike,
That is indeed very good information and crystal clear on the basics of the geometry. I still have not seen anywhere any reference to the tranny drop/pinion angle "ideal value" or "range", only that the operating angle formed by the height difference of the two yokes and the driveshaft length should be three degrees or less, if possible. I've come to the conclusion that as long as the transmission and pinion angles are equal and opposite for street applications it is OK, provided your operating angle is in limits. Then again, like several have said, being adjusted totally different may not cause any issues. To each his own... My question was really about coilovers, but this horse has been beat to death and I have a path forward.

A 1" spacer under the tranny mount will yield a three degree drop but makes things tight up front between pulley and fan. May have to cheat back just a bit, but this needed to be done.

Take a look at this. Maybe it will answer what you are asking.