Yes I know this topic has been run into the ground but I'm a dummy and I want to get this right the first time.
I have 4 degree down on the tail
I have 7 degree down on the pinion
This is a cal trac setup in an a body anywhere from 3100 to 3300 pounds.
Those reading put me at 3 degrees
Is this ok for a strip car?

I wuld run that That being said I think the location of the bolt up front matters more on Mopars than the other brands, most of the racer discussions I've seen on here on Cal Tracs say to use the lower hole and work on the preload and air gap to get thme to work I've never used them so keep that in mind Is this a stick shift or automatic car?

I forgot to add that the springs perches are not welded yet and I currently have the pinion at 7
Should I weld them in there?
Car is flat on the ground

better re-calculate that. 4 up on the pinion would put you at 0*, then you would have to roll down to what ever you wanted it set from there. 7 down puts you at 11* down

So bring the pinion up to 4?

o* on the pinion would be 4 down.

I was under the impression that you were the undisputed king of pinion angle setting. I seem to remember a video proving it.

Based on the measurements provided, the OP's pinion angle is currently 3º down relative to the tailshaft centerline. With leaf springs, I'd shoot closer to 5º, but I don't know how Caltracs affect that.

EDIT: After drawing it out, I agree with the pinion angle champ. The OP is currently 11º down.

glad i could help RV, as you can se now the other clowns will come out of the woodwork

I can't believe I agree! LOL

With Cal Trac and the tail being down 4, you want the pinion at 1up to 0. That will give you a -3 to -4 setting. If Calvert says -2 to -3 then you want the pinion up 1 to 2.

www.youtube.com/watch?v=KZ-m9ov3wYM

Does this video help (or does it make things worse)? It uses the relationship between the tranny and the drive shaft and the drive shaft and the pinion rather than the relation between the tranny and the pinion.

I guess in an attempt to simplify the subject, the relationship between the tranny and the pinion is often used, and the drive shaft is then omitted from the calculations. Seeing both methods used has caused a good bit of confusion.

And then more confusion comes from the terms we use. On the tranny, we are using the output end to describe it as down. But then on the differential end, the input end to often used to describe the pinion as down.

What is really happening in the OP's example, is that the tranny line is descending from front to rear on the car and the differential line is ascending from front to rear on the car. So, while the pinion points down, the differential line is pointing up.

All that causes some people to measure the angle between the shaft and a yoke and while others measure the angle between the tranny and the pinion. And then some people use the direction the pinion is pointing while other people use the direction the line of the differential is pointing.

I am not trying to argue which way is right. I am just trying to describe what is I think is happening to cause all the confusion on this subject.

Does Calvert use the tranny to pinion measurement or drive shaft to pinion measurement?

Let me get the haters and engineers stirred up off right here.........LOL!!!. This is a race car right? FORGET what the damn trans angle is. Measure the pinion to shaft angle and set it where you want it an go race the car. With the car "under power", you want the drive line angle to be as straight as possible. So do what you have to do to make that happen. And by straight, I don't mean equal angles or any of that other stuff. I mean STRAIGHT and as close to that as you can.

Whats going to happen.......is that after 20 pages of arguing, showing some drawings, the "god" illustration from Rossler, there is still going to be two sides to who is right........LOL!!!........But I won't be one of them. My one and only post right here and the way I have been setting up leaf cars for better than 30 years. In the end, do it how YOU want to

Monte

it obviously works both ways, one has to choose which way they want it. I think it has been proven that set off the drive shaft it has created vibration issues and caused failures. I have no know knowledge of setting off the tail shaft ever causing problems

Nothing else needs to be said,doing it the same way for over 50 years.My 65 hemi has the same shaft and ujoints that were put in it 20 years ago.

One last thing.........."static" setting means NOTHING. The car is NOT static, going down the track under power. So, if you go to all the trouble to get "equal angles" when the car is "static" all that goes out the window as soon as you drop the hammer and it separates the rear. Now if static, the pinion already has a "nose up" attitude in relation to shaft, in an attempt to equalize angles, as the rear separates and pinion rolls up this angle gets worse. I fail to see how this could EVER be better.

And how has it been "proven" that setting off the shaft, creates vibration and failures. WHO proved that. I have been doing it my way on race cars for 30+ years and I have never had an issue. So are you saying that nobody who has ever set it the other way has EVER had an issue. Parts break in race cars and that's a fact. If the shaft is out of balance, I don't care how you set it, you will have a problem.

Bottom line, set it how you want, as there is obviously controversy in what is "right" for a race car, really makes no matter to me either car. The only thing PROVEN, is that people don't agree and in the end likely doesn't matter in a race environment, as long as the joint is not at a compromising angle.

Lets see what another "chassis builder" thinks
http://www.wolferacecraft.com/pinionangle.aspx

I'am going with the full MONTE,bY GEORGE him too!!!!!

Dave, I was going to correct you but you corrected yourself. Yes, the OP is 11* down, To extreme to just Go with.

Id probably spacer up the tail shaft abit and raise up the pinion to get around 4* down max.


To the OP, You are at a True 11* down. Measure your Pinion to Driveshaft to see what number you get there. Lets see in Your case how close to the True pinion angle you can get by measuring between those two. Lets see how That number compares to the True pinion angle.

I can top that, my car hasn't used a drop of fuel since july of last year. Just pickin at you Bob

it wouldn't do any good to post links of known problems caused by vibration, been there done that. you just poopoo them

For you guys that use the drive shaft... a very simple way
to check is using the U-joint at the rear.... put a spacer
on the cup(this is to get you out far enough to get it flat..
take a reading on the spacer making sure its at the bottom..
turn the shaft 90* and do the same... the difference is your angle
and adjust if needed... remember the U-joint is attached to both
the shaft and the diff

Shame on Wolfy for putting bad info out there on pinion angle. Just another Misinformed individual helping the confusion.

If he stated Pinion angle with a 0 degree tranny/driveshaft driveline his info would be correct, but he doesn't state that.

I think Wolfy should be hung up by his toe nails and slapped around abit for that poor incorrect info.

Also, Not a hater or a engineer, just the Facts. No matter Who I am, these Ujoints like to work in a ideal parameter. Both Camps do try to achieve that. Ones just more Accurate.


Edit, I mean all this in a Friendly way. Clicked on a bunch of smileys but they didn't show. I think we are all a big Family.