pinion angle?

whats a good pinion angle to start with mine is set at -3 1/2 degrees now i was told thats way to much

You want the driveline in the straightest line as possible under power...............pinion angle depends on a lot of variables other than just a number.

What type suspension?

all upr front and rear soild bushings stock rear springs lakewood 90/10 and 50/50 with anti roll bar with that angle the car 60ft. is 1.38 - 1.41 ass end off car does not move on lauch but the front extends strut with out pullin the wheels is this good or shud it be pulling the wheels any at all its a 523 with f-1 i figure it wood be tryin to go to the bumper with that much pinion angle

Not trying to piss on a fire but........... pinion angle on a stock suspension car is not as important as people think. (YES, GO AHEAD AND START YOU DANG BASHING)

Things like ride height, angle of lowers compared to parallel, front end height, spring rates and shock settings are more important. To be honest, I have never even checked pinion angle on my ride. If I was to guess a number, I would say around 1.5-2 degrees but it may be as little as 1. Setting up everything else correctly is a lot more important. Squaring the the rear in the car with the lowers, setting axles square side to side in the car with ONE upper and then just attach the other. If you have an ARB you can just preload a little with it. If not then you can use one upper but you probably don't need much.

Again, not trying to start anything negative but most people don't even know how to measure pinion angle correctly.

i undderstand that but i dont want to bind the u-joints up and break em or cause any other problems just would like to have a safe # to set it at

whatbumper wrote:Not trying to piss on a fire but........... pinion angle on a stock suspension car is not as important as people think. (YES, GO AHEAD AND START YOU DANG BASHING)

Things like ride height, angle of lowers compared to parallel, front end height, spring rates and shock settings are more important. To be honest, I have never even checked pinion angle on my ride. If I was to guess a number, I would say around 1.5-2 degrees but it may be as little as 1. Setting up everything else correctly is a lot more important. Squaring the the rear in the car with the lowers, setting axles square side to side in the car with ONE upper and then just attach the other. If you have an ARB you can just preload a little with it. If not then you can use one upper but you probably don't need much.

Again, not trying to start anything negative but most people don't even know how to measure pinion angle correctly.

I agree, pinion angle should be set to keep the driveline happy.

whatbumper wrote:not trying to start anything negative but most people don't even know how to measure pinion angle correctly.

That is a good point. It is a measurement that does get figured incorrectly often times (in both separate street & drag combos) when people use the angle of the pinion in reference only to the ground, instead of correctly referencing it's angle to the driveshaft's angle. The correct way gives the combined true rear U-joint operating angle (aka pinion angle).

all junk wrote:whats a good pinion angle to start with mine is set at -3 1/2 degrees now i was told thats way to much

If your number of -3.5* represents a true U-joint operating angle, it sounds excessive for a drag car if your using solid bushings. But if your -3.5* number is only in reference to the ground, it's pretty much a useless number (at this point) without also knowing the driveshaft's angle. You should check Wolfe's site, it might still have U-joint operating angle suggestions for the different rear bushing types commonly used.

all junk wrote:i figure it wood be tryin to go to the bumper with that much pinion angle

In my opinion, (unless you have a pinion snubber traction device) adjusting "pinion angle" should never be used as a chassis tuning tool to get a car to hook. This is because the angle of the pinion has no mechanical effect on the suspension other than by excessive pinion angle causing dangerous U-joint binding. It should only be adjusted to achieve either a "street/highway" angle profile, or a "drag only" angle profile to help both the front & rear U-joints survive. Now that's not to say that there aren't some out there that have had success using U-joint binding as a chassis/suspension tuning tool. From what I have read on another forum it sounds like Team Z might sometimes advocate using excessive pinion angle/U-joint binding as an adjustment tool for the "stock suspension" stuff, (if I remember correctly it was referred to as "thinking outside the box"). And theres nothing wrong with that, it's fine if U-joint binding works for some people. I just think it's too dangerous to fool with.

How did you find that 3 1/2 degrees?

What is your engine/trans angle?
driveshaft angle?
rear pinion angle?

What is the angle of your LCA compared to parallel?

Just trying to help a fellow fox guy out.

[quote="richter69"]

whatbumper wrote:Not trying to piss on a fire but........... pinion angle on a stock suspension car is not as important as people think. (YES, GO AHEAD AND START YOU DANG BASHING)

Things like ride height, angle of lowers compared to parallel, front end height, spring rates and shock settings are more important. To be honest, I have never even checked pinion angle on my ride. If I was to guess a number, I would say around 1.5-2 degrees but it may be as little as 1. Setting up everything else correctly is a lot more important. Squaring the the rear in the car with the lowers, setting axles square side to side in the car with ONE upper and then just attach the other. If you have an ARB you can just preload a little with it. If not then you can use one upper but you probably don't need much.

Again, not trying to start anything negative but most people don't even know how to measure pinion angle correctly.

x3 now a 4 link pinion agle drives it into the ground i wouldnt worry other than having enough to keep the shaft in.

The pinon angle should be correct even no matter 4 link, ladder bar, or stock suspension. Obviously, it is easier to maintain it with a 4 link. IC changes do not have to reflect a difference in pinon angle. If your car works better after changing pinon angle, then your are getting it out of a bind and closer to center. Negitive 1 to 2 degrees should work best on any car.

The pinion (or it's angle) can't "drive" a 4-link suspension (or anything except a pinion snubber setup) into the ground, engine torque & the placement (length & height) of the I/C does that.

We set up our new rear this weekend. Stock suspension car. We extended our wheelbase almost an inch. Set up the rear side to side and squared it up in the car. After doing all of that we checked the pinion angle just to post it here. We normally don't care. It checked out about 1.5 degrees. This was measuring the crankshaft angle, drive angle, rear angle and figuring the actual pinion angle from that.

Sounds like you should have happy u-joints.

whatbumper wrote:We set up our new rear this weekend........It checked out about 1.5 degrees.

Just looked at Wolfe's site again and the pinion angle vs Fox bushing type suggestions are still there. Your -1.5* looks right in the desired area.

i run - 3.5 and my car loves it

badnotch wrote:i run - 3.5 and my car loves it

you sure Gerry ???

100 % went from 1.65 sixty with a -1.5 to a -3.5 to a 1.28 didnt wheel stand for the hell of it

I would have to extend my lowers even more to even get 3.5 degrees. I already have them extended almost an inch. Wheelbase is right at 102" now. Consistently sixty foot 1.21.

Neither here nor there, I don't use it for tuning aid anyways. I may be a little stupid but I haven't figured out how it effects how a car hooks anyways if everything else measures out right. I thought it was just used to keep your u-joints together.

i was told the 4 bar setup like a mustang was kinda like a short 4 link and the pinion was how you put bite in the car and took bite out correct me if im wrong but i hope that isnt stupid for me to say but thats what ihave always been told

whatbumper wrote:I haven't figured out how it effects how a car hooks anyways if everything else measures out right. I thought it was just used to keep your u-joints together.

What is happening is he is putting the U-joint(s) in a greater bind increasing the frictional drag & taking away some of the engine power from reaching the rear tires thus allowing them a better chance too hook. It's nothing new, some of the old Pro Stock guys tried this way, way back in ancient times to kill some launch power. This was back before there was the advent of the good, highly adjustable suspension components like we have today. But a safer way to kill some of the engine power reaching the tires during the launch is to leave the pinion angle at -1 to -1.5* and "steal away" some of the launch power another way (like with engine timing using a Digital 7). At least with the 7 box you can ramp the timing back to where it needs to be after the initial launch, and your not increasing the friction/binding of a loaded drive line component. He could have also achieved a (somewhat) similar effect during the launch by going with a two speed trans vs a three speed.

Of course if someone decided they didn't want to use the band-aid trick of binding up the U-joints trying to get a car to hook there is always the "old fashioned" way of getting a car to hook........by adjusting the actual chassis/suspension (aka shocks, struts, I/C placement, air pressure, moving weight around, etc, etc) since that's what it's there for.

all junk wrote:i was told the 4 bar setup like a mustang was kinda like a short 4 link and the pinion was how you put bite in the car and took bite out correct me if im wrong but i hope that isnt stupid for me to say but thats what ihave always been told

Don't worry, it's not a stupid question.

It can be hard to weed out the misinformation that has been around forever. This myth that somehow the pinion magically causes the "bite" (vs engine torque & the suspension doing it) even though the pinion isn't physically/mechanically interacting with a moving or fixed suspension/chassis component never seems to go away. The only exception to this is of course a "pinion snubber" traction device because with this setup the pinion's physical actions during the launch (upward rotation) are transferred to a chassis mounted bracket holding a rubber snubber. Part of the myth stems from ancient times back when stuff like ladder bars (and such) were much less adjustable. Back then sometimes when someone lowered/raised the bars to other front holes, they couldn't correct the pinion angle back to where it needed to be afterwards (or were too lazy to try). It lead to the confusion as to what really caused the suspension to have more/less leverage, the different bar hole & a different I/C....or the pinion angle.


As mentioned the combined pinion & driveshaft U-joint operating angle (aka "pinion angle") can't "hit" a tire, engine torque & the rear suspension leverage does that. The only "side effect" adjusting pinion angle can have is when adjusted to the point that it causes the U-joint to operate in an increasing bind. This increased bind causes more friction which in effect uses up some of the engine power from reaching the rear tires. So in effect your not "smacking" the tire with pinion angle, your actually removing some of the engine's usable torque/power from the initial launch giving an over powered tire more of a fighting chance. But as I have said before some people do have success using a bunch of pinion angle & U-joint binding to get a car too hook vs adjusting the suspension instead. But a possible U-joint failure from increased binding is not something I would want to mess with.

It's a small part of the even bigger misconception that "hitting" a tire harder means it will always "hook" harder. It incorrectly assume that because a given action caused "more" traction, it must therefore have been a more energetic or more violent action. Nothing could be further from the truth since a tire needs the "correct" amount of applied energy to hook as effeciently as possible. Correct means the right amount, not too much, and not too little.

Since it hasn't been brought up yet I thought I would add that a number of driveline sites say that there is a direct correlation between max accepted safe U-joint operating angle vs a given driveshaft RPM/speed. As max driveshaft RPM/speed increases, max safe operating angle decreases.

The RPM vs angle chart you see on a number of sites has these numbers........

SHAFT RPM vs MAXIMUM OPERATING ANGLE
5000..... 3.25°
4500..... 3.67°
4000..... 4.25°
3500..... 5.00°
3000..... 5.83°
2500..... 7.00°
2000..... 8.67°
1500..... 11.5°

Even though the charts usually top out at 5000 RPM, from these numbers you can figure a close rough estimate for higher driveshaft RPM's too.


And Spicer's site says 3* or less for best life.