What does a caltracs car rotate when launching? What would the proper resting pinion angle be.

I have some parts to finish bolting back on the engine and then I'm going to check mine out...You guy's all have me curious as to what it really is.
Mine would be a low 12 second car at best with probably zero traction issues but I would just as soon have it right...
Monte...the bottom diagram is similar to mine however with a stock 69 Dart chassis I don't see the trans being downhill at that extreme of an angle. I'll check it and find out...Thx...

I don't see a problem with the set-up you posted.

If the transmission slopes downward 1.25 degrees toward the rear of the car and the pinion slopes downward 2.7 degrees toward the front of the car, the static pinion angle is 3.95 degrees negative, which is acceptable.

The pinion will "go positive" only if it rotates upward more than 3.95 degrees under power. In other words, 3.95" of upward rotation will cause the pinion to become parallel to the transmission.

Monte, Read this ABOVE, Do YOU , see any TP, angles here????

If SO, Show me. From YOUR Drawing, Nobody ever stated setting a rear up static and a Parallel angle with NO pinion adjustments as you would do with a Straight driveline for racing. You do it for BOTH. I SAY it Again, YOU do it for BOTH!!!!!!!

Your Drawing was a What if, but you stated happens many times. "SO HERE IS YOUR ANSWER"

Simply put, on a drivetrain that has a lower front u-joint pointed 3* down and a higher rear u-joint pointed 3* up,

That's a" Parallel Driveline".

Now, a True race car, Straight driveline, IF set up like you Should. "RIGHT" Its Also a "Parallel Driveline"


FROM there "BOTH" "BOTH" need pinion Adjustments FROM PARALLEL to account for axel wrap up.

Without that Adjustment, EVEN a Straightline driveline will "TEEPEE"


WHAT, if anything don't you understand about the above.

You stated I was a Expert, Im here to answer any further Questions for you. AS is, CAS, Evil Spirit, and others

SINCE, in Your mind, You keep thinking TP Effect, that tells me, your not getting it yet, clear as day to me.

You guys arguing with Monte, BG and whoever. I'm just sitting back laughing. In what are you faster? Do you even have a car? Lol or a wheelchair

Put your Johnson back in your Pocket. LOL. Its Not about Whos faster, or Whos Daddies Bigger.

Its about Whos Better looking, or maybe Pinion angles. lol

Lmao, then quicktree is the big loser here

I'm starting to wonder if Sport440 even knows who Monte is.

I have no idea how you came up with that if the tail 1.25 down, 1.25 up would be 0* then you would roll it DOWN to what ever you wanted it.

ok how much do you want to race for?i'll drag my wheelchair up there and drag that ass

and since it wont let me quote your loser comment. how do you figure that? just look around there are a lot more people here that don't use the drive shaft then those that do.

Anyone who thinks the laws of physics don't apply to a RACE CAR has "no clue how to set up a RACE car".

Regardless of how you define driveline angle, working angle, operating angle or pinion angle, please give me one reason why you don't want the pinion to run directly in line with, or parallel with the transmission when a RACE CAR is UNDER POWER.

Google is also your friend.

Did you even look at the video demonstrations in this thread?

The loser comment was reffering to how pretty you are. And this thread reminds me of a bunch of broke jokes trying to argue with Jim Cramer on investing.

Monty, why don't you tell us how to set up the correct pinion angle instead of telling everyone they are wrong? Tell us how YOU set up both scenarios, trans lower than the rear and trans above the rear. Leaf springs too. IMO, unless you provide some examples your posts are nothing more than opinion. Long on opinion and really short on facts.

Don't Worry about Who is Who.! Whats your stand on pinion angle from my above post???? You Count too.

One thing to me is how ever you set pinion angle as I have basically done it by the eng/trans and pinion centerlines paralell under power you always have to check the front and rear joint angles. You should want about .5 but no more then 2 degrees for joint angle. On a street car you want some joint angle so the joint works and keeps itself lubed. If any of them are to much even with the eng/trans and pinion lines parelell then you have to make the changes. Most stock body cars will never run into that but of course race cars with built chassis could have either the trans or pinion higher and to much even when you get the parellel centerlines if the joints have to much workable angle it will cause problems. Then you will have to modify it to correct it. To me thats sorta what Monte is saying about the positive angle which the bottom line is the joint wont work good at that angle. Thats one reason I always make a drawing of what I am working on so I know just what I am working with and if the shaft is running uphill or downhill. But I do use the parelell centerline process and I always double check the joint angles when done to be sure they are also in limits.


Whats the deal with how fast you are in this ??? Does it mean you are stupid if not fast enough ?? Ron

I HAVE........NUMEROUS times, but everybody wants to argue about it, talk about parallel planes, driveline angles and a bunch of other stuff that DON'T matter......PINION ANGLE is simply THAT......PINION ANGLE. And pinion angle is SIMPLY defined as the relationship of the pinion and the driveshaft.....That's it, ALL there is to it....... So if you want 3 degrees of pinion angle, you break out the protractor, measure the pinion flange, the driveshaft angle, set it at 3 degrees difference and you are DONE......period, end of story. Don't matter if the trans points straight, down, up.........it don't freaking matter. So there, I have explained it for about the umpteenth time and shortly the others will be along talking about up and down angles, parallel universes, black holes and all kinds of other stuff that doesn't matter and how uninformed I am..........One more thing, ANY setup that has the pinion pointing UP and also the rear of the driveshaft pointing UP........is flat WRONG. The ONLY time and I repeat ONLY time the pinion could point UP and possibly be right, is if the REAR joint is LOWER than the front joint. In ANY scenario that the FRONT joint is LOWER than rear, the pinion should NEVER....EVER point UP. That's just as plain as I know how to make it.

And my FACTS, come from 35+ years of both building and setting up race cars, from Stockers to Pro-Mods. Not everybody, few in fact, have tube chassis cars, with the motor properly aligned to the rear to make things ideal. So in that scenario, you deal with the hand you are dealt. And ANY reputable chassis builder will tell you that IDEAL, is to have all this stuff in perfectly straight alignment when the car is under power. This fact the others do NOT argue, but this only happens in purpose built cars generally. So in lieu of "ideal" alignment, you do the best you can under given circumstances. THAT entails having it straight IN THE REAR while under power, the only angle being the FRONT joint.....and THAT is why PINION ANGLE is defined as the relationship of pinion flange to driveshaft. And that is why leafs, ladder bars, 4 links etc have different numbers. Some rotate more than others to align the pinion STRAIGHT with the driveshaft, while under power......

But like I said, others will be along shortly with things about equal joint angles, parallel planes and a bunch of other stuff that doesn't apply to RACE cars..........so form your own opinion. So there is NOTHING more I can say, nor can I be any more clear. Also, I won't change their minds and they won't change mine, so it is up to you to figure out who to listen to

Monte

As far as Google goes - Google "pinion angle" and you will be led to a variety of opinions, forums, and "tech" articles that pretty much mirror the posts here. Many simply call "pinion angle" the angle of the rear u-joint - many others call it the angle between the centerlines of the engine/trans and the pinion. I could post on a forum that you need a pig in the trunk to set correct pinion angle and it would appear on Google and somebody would believe it and quote it on a forum. So you can quote 10 that agree with you and I can 10 that agree with me and it's still just matters of opinion.

So here's the rub - call it what you want - pinion angle, rear u-joint operating angle, WHATEVER - only setting the rear angle to a spec and not referencing it to the trans is inviting driveline vibrations and reliability issues. Automatically turning the pinion nose down when the trans is also tipped down results in operating angles that are not parallel and results in a weaker driveline and possible vibration issues. I call pinion angle the total package - referencing the pinion to the engine/trans centerline - obviously you do not. To reference to pinion to the trans, the driveshaft does not need to be in.

So looking at the BIG PICTURE, when you consider strength and vibration, if your driveline angles, pinion angles, whatever you want to call them, are like the lower picture UNDER POWER and not parallel THEY ARE WRONG. The pinion doesn't get driven at a constant speed which is crucial to maximum strength and minimal vibration.

The loser comment was reffering to how pretty you are. And this thread reminds me of a bunch of broke jokes trying to argue with Jim Cramer on investing. [/quote]lol well we all know im purty

now that we have this solved again, I see a nice 9" - 8-3/4 thread on the board

Monte....I get that your not budging on your opinion...and thats ok....but your wrong....period - get over it.

For those looking for facts and thoses independent from the sheep hearding concept of the urban legends. ...look no further than the professional presentations in this thread for the proper methods.....I believe one video clip was produced from the Dana Spicer corporation. Nothing more needs to be said.