rear end pinion angle?

[Detroit Gearbox]

How do i do that when the Axle sits on top of the leaf spring? Put 2 jack stands under the leaf springs and just set the axle on the springs without tires?

Something like that... as long as the weight of the vehicle is under the springs.
You don't want the axle free hanging.... it has to be at ride height.

http://spicerparts.com/anglemaster/measuring-angles
http://www2.dana.com/videos/dana_vid.html

[greatwhiteLSC]

Try to measure your angles from a machined surface or the output shaft and pinion gear themselves. Measuring from the housing surface isn't always 100% accurate, but should get you pretty close.


-Sent from my iPhone using Tapatalk-

[wikdsvt]

since I have the stock rear end, can I just compare the angle of the leaf spring perches to the angle of the pinion gear shaft and just transfer those angles to the new rear end?

[igotaneed4speed]

Curious who told you that?

So +5* would act the same as -2,-2.5* I just wanna be sure that's what your saying. The U joints would just wear out faster.

What did the same guy tell you about pinion angle in relation to instant center?

I would love to sit and listen to this guy talk. We could meet at Zimmermans on pulled pork and rib night.

no because to get +5 or -2 in a mustang you would have to change the length of the control arms, the pinion angle is the result of that. Pinion angle itself does not effect traction the change in control arm length does, which changes instant center, the pinon angle does not.

Please tell me where in any calculation used to find IC is pinion angle used? Everyone I have ever seen uses control arm length and angles (angles are found by using front height vrs rear height) Never is pinion angle used, it is a result of, simply a measurement not a set-point! Please educated me how pinion angle effects IC? You can do it on here, Dave has a account on here he can comment here too.

refer to link for a picture of what i'm talking about.

http://www.baselinesuspensions.com/instant-center.php




example... If you took a factory 8.8 and mounting locations for a fox body then took another 8.8, cut the mounting brackets off the tubes, rotated the rear end and weld the brackets on in a different location (not the same center line to pinion as the factory one) You could put either one of those rear ends in and out of the same car not changing anything an the car would work the exact same but they would have different pinion angles. This is exactly why you can have two exactly the "same" built cars, with the same parts, engine height, weight bla bla bla and one will work with a resulting measure of -2 pinion angle and the other will blow the tires off at -2. Simply because every rear end might have not had the brackets welded on at the same center line to pinion. A half degree in rotation of the mounting brackets on the housing and the entire suspension geometry including IC is different from the other car but you still get the same pinion angle measurement.

[igotaneed4speed]

Another article supporting my view, please tell me Jerry Bickel is wrong Anthony....


http://www.carcraft.com/howto/91758/





"Pro Stock chassis builder Jerry Bickel assures us, “there is no mystery to pinion angle.” Setting the pinion angle is the final step in driveline alignment. The goal is to create a straight line from the back of the crankshaft through the transmission, driveshaft, and the pinion of the differential—under load. Due to the tendency of the pinion to rise under load, some angle must be present at rest.

How well the rear suspension controls the position of the rearend is the most critical issue that determines how much pinion angle will be needed. Some types of rear suspensions offer more control than others and require different angles. According to Bickel, a ladder-bar suspension normally requires ½ degree of pinion angle, a four-link requires 1-2½ degrees, and a leaf-spring suspension requires up to 6 to 7 degrees. In all examples, we’re talking about negative pinion angle, i.e., the pinion is nose-down in relation to the driveshaft. Bickel says a straight driveline delivers the most power to the rear wheels. For more on race car chassis tuning, Bickel offers classes as well as detailed books on the topic.
Ray Currie of Currie Enterprises, which specializes in rearends and rear suspension systems for race, street, and off-road applications, agrees that pinion angle is a pretty simple (there’s that word again) concept. He explains that a universal joint is designed to handle between 1 and 3 degrees of pinion angle. This is a safe operating range for the U-joint. If the U-joint is forced beyond its normal range, it can hyperextend and lead to catastrophic failure. Currie always strives for 2 degrees of pinion angle on a street car regardless of the type of rear suspension being used.
With a leaf spring–equipped car, the differential movement isn’t nearly as controlled as that of a four-link suspension, so more angle may be needed to prevent the U-joint from hyperextending beyond zero degrees under load. Sometimes people increase the pinion angle to increase dragstrip bite, but Currie does not recommend this approach for a street car. Currie says “ideal is ideal,” and the correct pinion angle should be incorporated in the part-time as well as the full-time race car.
Suspension specialist Dick Miller bases pinion angle settings on horsepower. Miller likes to see 2 degrees of negative pinion angle (relative to the driveshaft) on applications in the 400hp range, 3½ to 4½ degrees in the 500hp to 650hp range, and up to 7 degrees with 700 horses or more. Miller also acknowledges that the greater the pinion angle, the more horsepower the driveline will consume, but it’s a compromise that must be made. Miller notes that these angles are merely guidelines, and each individual combination should be fine-tuned. "


Read more: http://www.carcraft.com/howto/91758/#ixzz25t04svnZ

[igotaneed4speed]

Here's another with Mark Williams being quoted on how driveshaft angles only effects the driveline happiness nothing about if changing traction here. Maybe you should start a school of Anthony and teach Jerry Bickel, Ray Currie & Mark Williams how things should be since you know better.

Really? Pinion angle has no effect? You sure about that?

lol

You guys should be the TA's in that class...


http://www.hotrodheaven.com/tech/chassis/rideheight.htm

"Engine and Pinion Angle

Engine and Pinion Angle: There has been numerous "hear says" about what the pinion angle should or should not be. Hopefully this will clear up a lot of misconceptions. One of the biggest misconceptions is the engine angle is it is relative to the frame. Engine, pinion angle and ride height is all relative to the ground.
Most engines are set at 3 degrees, when you look at the side of the intake manifold on a carburetor engine you will notice the manifold has a wedge in it. This wedge is to allow the carburetor to sit level. The main purpose of having an engine angle is to allow for more room in the passenger compartment by having a smaller tunnel. That is why the car manufacturers build front engine cars with the engine at an angle. Drag race cars have a 2 to 3 degree negative engine angle, the engine will tip down in front. Having this negative angle allow for better weight transfer to the rear of the chassis. The 3 degrees you keep hearing about is the recommended angle for carburetor cars with intake manifolds set at 3 degrees. With the engine and pinion set at 3 degrees they do not line up directly and requires you to make them parallel. This misalignment allow the u-joints to rotate on a street car.
There is a misconception regarding the pinion angle on drag cars. I have seen many people advise that the pinion needs to be 2 - 7 degrees down. In relation to what? I disagree with this theory and set-up. The pinion needs to be "parallel" to the engine angle or in a straight line for the least amount of horse power lost.
This following is a quote from Mark William's web site,
"There is a general misunderstanding bout "dropping the pinion down" several degrees. This is a practice that could be applied only to leaf spring cars without any traction control devices where springs can “wrap” and change pinion angle. This practice would not apply to 4-link, ladder bar or torque arm equipped cars. Failure to maintain matched and minimum operating angles increase erratic non-uniform output velocity from the drive shaft to the differential."
You can set up the engine angle at almost any degree just as long as the transmission is perfectly inline with the pinion yoke. However, when the engine and pinion yoke is in direct line, it does not allow for the rotation of the u-joints. This straight alignment is mostly used on drag race cars.
If you would crawl under your car and look at the pinion angle you will notice it is the same angle as the engine/transmission (they are parallel). A good example of having negative engine/pinion angle is when you lower a 1 ton crew cab where you lower the front more than the rear and there is quite a "rake". In this case you have to put a wedge on the back side of the saddles to tip the pinion angle down.
If you are building a chassis you need to first determine ride height. This is the most important thing you need to do. Decide what wheels and tires you want to use before you pick up the welder. If a chassis builder or a salesman does not ask you what tires you are going to use do not buy from him. How can he build your chassis without know the tire diameters? How can he set up the front end and engine angle? What they do is build a chassis based on what they want or think you should have and not what you want.
Now determine the ground clearance you want for your oil pan. Set your motor mounts based on this and the angle to best fits your car. Try to set the transmission directly inline with pinion yoke and if that is not possible set the pinion parallel to the engine angle. Before you weld the brackets on the rear end housing be sure that the rear end was set at "ride height". Ride height is where the rear end would be with the car done.
If you find a chassis builder or salesman that says you have to have the engine angle at 3 degrees and there is no other angle you can set if at, find another chassis. He apparently does not understand the principles of setting correct engine and pinion angle. Also no chassis builder can build you a chassis with optimum suspension without knowing proper "ride height".
I learned about chassis from two men, Russ Meeks and Jack Slavik. These two forgot more than most people know. Do yor remember the 30 rear engine roadster built in 1971 and the Revellution Funny Car? Meeks built the roadster and Slavik built Art Whipple & Ed McCulloch's funny car. Meeks built my 30 roadster in 73 with a Morris rack and pinion mounted on the axle, front 4 link and rear 3 link with a driveline traction bar. Meeks was cutting two spindles and welding them together in the 60's, Super Bell called him and asked him how to make them. They still use Slavik's 2 degree negative engine angle when building funny car chassis. These men were the pioneers of suspension technology. "

[mikesfastss]

I'm pretty sure the op is a leaf spring car,so control arms are not a factor in this situation,it did say in the article that pinion angle does apply in leaf spring cars.

[igotaneed4speed]

I'm pretty sure the op is a leaf spring car,so control arms are not a factor in this situation,it did say in the article that pinion angle does apply in leaf spring cars.

It says you have to take in account for spring wrap and bushing flex when setting pinion angle on leaf spring cars it does not say the pinion angle will effect traction, the cars ability to hook or instant center because it does not.

Instant center on a leaf spring car is found way different that 4 link cars, all you would do is draw a line up from contact patch to the front leaf spring mount there is no intercepting line. Pinion angle has nothing to do with that and ha zero effect on traction at all.

[Anthony]

Ok. You win. :-)

Prostock/promod chassis and stock suspension is the exact same thing!



Thanks for the lesson!


I had to edit, my other comments, it's not worth my time.

Please set up a stock suspension, small tire car the same way as a prostock car.

[1BADAIR]

in the real world pinion angle does effect traction(do to IC) cause 99% of the world isnt going to cut the brackets off to adjust PA without changing anything else