Pinion Angle | Rear Suspension Twist | Rear Anti Roll Bar

What Pinion Angle is and what to shoot for on your drag car! Rear Suspension twist and why I recommend a Rear Anti Roll Bar!
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Don't make pinion angle too difficult, but don't ignore it either. This video discusses what pinion angle I shoot for and why. It is not about adding bite!! Also, let's understand the twisting forces on the rear end so we can tune the rear suspension accordingly. When we talk about pinion angle in drag racing, we are not actually referring to just the angle or slope of the pinion shaft alone, but the relationship of the pinion shaft centerline angle and the driveshaft centerline angle, so more technically we are talking about the working angle of the U-Joints.
You can use the double adjustable shocks and your coilover springs to help counteract and/or slow down these forces, but the recipe is even better with an Anti roll bar, ARB, and everything working together. This video teaches you how to find your pinion angle and what angle to shoot for on a full drag car rear suspension.
How to setup double adjustable shocks and coil springs for drag racing does not have to be a mystery. How to tune rear shocks for drag racing also known as tuning coilovers for drag racing. Drag car alignment is critical as you know for your safety and the safety of the other driver.
Budget friendly Pinion Angle Gauge:
amzn.to/2Zc3MLt
Digital Gauge:
timmcamis.com/shop/digital-pr...
Tim's Pinion Angle Video with Digital Gauge:
• Rear Suspension Overvi...
Finding the slope:
www.calculator.net/slope-calc...
Once you have the slope equation for both the driveshaft and pinion from link above you can use
this page to calculate the resulting angle:
onlinemschool.com/math/assist...
Samson Performance of Sam's Alignment in North Charleston, SC.
samsonperformance.com - This site has our email and shop info along with remote services explained. Yes, we now offer Online Suspension Tuning services!! Go to our website to get more info.
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KevinWilsonSBC
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Amsoil Products for all your high performance needs:
www.amsoil.com/?zo=5439621
#suspension #dragracing #coilovers #chevy #horsepower #qa1 #dragcar #shocks #streetracer #streetrace #caralignment #coilsprings #suspension #4links

[@paulmcdonald3570]

Your ability to explain what’s happening and break it down is great! You don’t give yourself enough credit my man!

[@codyblack5490]

Basically everything I know about suspension is from watching your videos. Very helpful

[@KevinWilsonSBC]

Right on! Go fast, go straight! Be SAFE!

[@codyblack5490]

@KevinWilsonSBC trying. Thanks for all the help.

[@mcraceworks]

Very good information as always. Thank you for making these

[@lilpickleracing]

so much good free info, thank you

[@KevinWilsonSBC]

godecki motorsports thanks so much for your comments and supporting the channel! Go fast, go straight! Be Safe!

[@markpollard500]

Thank you I really needed this knowledge! Really appreciate your videos!

[@KevinWilsonSBC]

Mark Pollard thanks so much for your comments! Go fast, go straight! Be Safe!!

[@stevelangworthy9553]

So much good stuff to absorb and apply here. Thanks!

[@KevinWilsonSBC]

You're so welcome! Go fast, go straight! Be SAFE!!

[@lewis4536]

Thanks Kevin. Really enjoying you videos. Been involved in drag racing for many years in England. Now building our second car after a very log gap. Wow how things have changed. Anti squat was never a thing in my day. Keep up the great work I’m buying in on your theory.

[@timk5275]

great video, I've been a mechanic for 30 years, drag racing longer , you're on point im in the process of building a grudge s10 and was looking for some info on DA shock settings info . i came across your videos and am very impressed with not only your knowledge but your knack for explanation .... i"m always willing to learn more , and today i did . thank you

[@KevinWilsonSBC]

Thanks so much, Tim! I appreciate you taking the time to comment. Go Fast, go straight! Be Safe!

[@justdale1966]

Wow thank you so much you've gone over things I forgot about 25 years ago keep it up I'll keep watching I'll keep learning I'll keep remembering

[@KevinWilsonSBC]

Dale Chirstopher thanks so much for your comments! Go fast, go straight! Be Safe!!

[@YerkitRacingChannel]

Great information as always Kevin! Thanks again for all you do!

[@KevinWilsonSBC]

Thank-you so much and for supporting the channel like you do! Go fast, go straight! Be SAFE!!

[@YerkitRacingChannel]

@@KevinWilsonSBC happy to be a small part!

[@josephfigueroa3527]

I love these videos, I can't wait to be a menace in Hard Tire.

[@KevinWilsonSBC]

Joseph Figueroa thanks so much for your comments! Go fast, go straight! Be Safe!!

[@neilhansen9886]

Great info with drawings that can be understood

[@KevinWilsonSBC]

neil hansen thanks so much for your comments! Go fast, go straight! Be Safe!!

[@mrborla]

great video thnx wilson 🙏🏼❤️

[@KevinWilsonSBC]

You are very welcome! Go fast, go straight! Be SAFE!!

[@scottnettellracing35]

Nice job Kevin

[@KevinWilsonSBC]

Scott Nettell thanks so much for your comments! Go fast, go straight! Be Safe!

[@raymondmoreno7442]

Thank you for a great video learned a lot

[@KevinWilsonSBC]

Glad it was helpful! Thanks for commenting! Go fast, go straight! Be SAFE!!

[@caesarnunez4233]

Nice exsplanation!!

[@KevinWilsonSBC]

Thanks! 😃 Go fast, go straight! Be SAFE!!

[@bruceyblowback8748]

Exactly what I was after, very well done in explaining it. Building a Ford Falcon stationwagon to drag here in Australia 🇦🇺 and I want to keep it as a sleeper, it came from factory with leaf springs in 2004. Awesome info.

[@KevinWilsonSBC]

Glad it helped! Go fast, go straight! Be SAFE!!

[@69jagss69]

Great job brother

[@KevinWilsonSBC]

69jagss69 thanks so much for your comments! Go fast, go straight! Be Safe!!

[@tima2477]

Wow... so much I want to say. Thank you first of all for sharing you knowledge. Second, I have been all over the internet searching all kinds of things because I myself have a 48 Ford coupe, flat black, and yes, it has a Malibu front end...I have had it since I was 15 that I used to drive/race and work on. . I CANNOT believe I have not run across your channel until now! Definitely makes me want to get back out there and get started on it again. I would love to talk with you sometime. New subscriber here for sure! Looking forward to more of your videos and the opportunity to chat!!!

[@KevinWilsonSBC]

Tim A thanks so much for your comments and for connecting! OMG on the 48 Ford Coupe with a Malibu frontend!!!! Would love to connect with you so go to my website at samsonperformance.com and shoot me an email with your contact info please. Go fast, go straight! Be Safe!

[@stuartbuckley8720]

So when I get my dual adjustable shocks and new rod ends I will revisit my pinion angle and set it to 1 to 1.5° negative. Thanks Kevin. Its currently at -5°

[@kevin_nagle]

@1:20 came back to this video a year later to rewatch it as I do often with all of your videos and what is like to say Kev is that the majority of us watching your uploads are by far no better chalk/whiteboard artists than you are 🤣 We understand your artwork it makes sense for us and that's alllll that matters!

[@Pegleg302]

Thanks !!!! I guess I will be getting an anti-roll bar !!!

[@KevinWilsonSBC]

jeff starch thanks so much for your comments! Go fast, go straight! Be Safe!!

[@craigshelswell8844]

Thank you for you vid it made a lot of sense appreciate it ..

[@KevinWilsonSBC]

Craig shelswell thanks so much for your comments! Go fast, go straight! Be Safe!!

[@craigshelswell8844]

Will be doing a adjustment on my pinion today it’s probably why my car is not 60 footin like it should ,you rock Kevin you explained it plain and simple .

[@Bushspaperplanes]

Your drawings amaze me but, for real, VERY good description and breakdown of your message. Even I took in what the message was. Great video

[@KevinWilsonSBC]

Matt Jevne thanks so much for your comments! Thank you for the kind words! I enjoy helping racers! Go fast, go straight! Be Safe!!

[@Bushspaperplanes]

@@KevinWilsonSBC I’m stuck with a driveshaft “hum” or “vibration”. Looking for experienced professionals to help me out. Hopefully I can in turn use this information to get me a better understanding of it and how it operates.

[@KevinWilsonSBC]

@@Bushspaperplanes do the basics for sure. New ujoints, balance of the driveshaft. I know you that, but sometimes it is best to just cover the basics for sure. I have saw many ujoints that looked good and felt good by hand, but underload, they are trash. Cover the basics first, unless you know you have some way out of whack angles going on! Go fast, go Straight! Be Safe!

[@Bushspaperplanes]

@@KevinWilsonSBC I’m not WAY out of whack but I wanna make the corrections right the first time and maybe be able to help someone else besides myself later. Numbers right now I believe are off somewhere in the 3 degree range. Going to take better measurements this Sat and plan for action after that. Driveshaft was professionally shortened, high speed balance etc. Spicer U Js are new but there’s still a slight howl. Pinions off and feels like it’s grabbing or binding at the diff

[@timgroleau1612]

Good stuff.

[@KevinWilsonSBC]

Tim Groleau thanks so much for your comments! Go fast, go straight! Be Safe!!

[@alexcorona1452]

This help I have a9 degrees. On the rear an 3in the front I tried fixing it with out going. Airbags

[@justgrazza4638]

Thanks for yet another informative video, Kevin. I have a question regarding rear ARB's. What weight bar would you suggest for a drag car? Is a heavier bar better than a light one or visa versa as a start point. I understand there would be a lot of variables to this answer, but just chasing a start point. Thanks in advance and please keep these great video's coming. I'm a 70 year old newb to drag racing, so learning quickly.

[@KevinWilsonSBC]

Grazza Herridge thanks so much for your comments & question on the rear ARB! LIke you said the more power, weight of vehicle being placed over the ARB and suspension stiffness certainly impact the decision. For example, I am running a bracket/sportsman series ARB and I definitely could use a stronger one. A 1.5" billet steel bar to me is a minimum and splined shafts preferred. Here is a pretty good article on this topic: www.dragzine.com/tech-stories/brakes-suspension/in-depth-extreme-drag-racing-anti-roll-bar-tech/ Go fast, go straight! Be Safe!!

[@brianboles3986]

Rossler Transmission has a great pictorial on pinion angle setting.

[@KevinWilsonSBC]

Brian Boles thanks so much for your comments! Go fast, go straight! Be Safe!

[@andyjones6361]

Kevin Another great video! I always wondered why with a standard differential the passenger side tire broke loose 1st. It is actually being lifted off the pavement. Can I use an anti roll bar in a leaf spring car? Thinking of the S-10. That truck was never intended to go 100+ mph!!! And it does feel squirrelly at those speeds.!! With the super light rear end on that truck I’m going to need to do all I can to add bite as the power goes up. Thank you, Andy Jones

[@KevinWilsonSBC]

Andy Jones thanks so much for your comments! Absolutely you can use a rear ARB with leaf springs. Go fast, go straight! Be Safe!!

[@ronaldlockhart8657]

I built a car in the late 1970s and it had a single leaf floater with latter bars, 1° negative pinion angle, it had 15/32 slicks, when I put 2° of pinion angle the forward bite was awesome compared to 1°

[@KevinWilsonSBC]

Thanks so much, Ronald for leaving a comment! I bet it did like the 2 degrees! Go fast, go straight! Be SAFE!!

[@jlo532]

Awesome video. Questions, with a radial car that separates 3" or more. What pinion angle would you start with and how would you set it? Rear end hanging or at ride height?

[@KevinWilsonSBC]

Jimmy Lopez thanks so much for your comments and questions! Like explained in the video I am setting pinion angle based on my how much twist the car has to get the u-joints lined up with the pinion centerline as close as possible for the hit and length of the run. Always set pinion angle with the car's suspension loaded, whether you have it on stands, jacked up, or on blocks. Go fast, go straight! Be Safe!

[@Lunnajs]

It is my understanding that you should set pinion angle so that when loaded up the angle at pinion and angle at front u-joint (transmission) are the same. Otherwise you will get oscillating rotations at your pinion. That to me seems more likely to have an effect than u-joint life because you want some rotation in your bearing cups to keep the bearings moving to not create peening in the bearing races. As far as the axle rotating up at the passenger side and down at the driver side you also have an effect from the chassie not letting your motor twist along with the crankshaft twisting the chassie counter clockwise and putting more weight on your right rear tire?

[@KevinWilsonSBC]

Lunnajs thanks so much for your comments! Go fast, go straight! Be Safe!!

[@Nobody-ld7mk]

The word you're looking for at 10:15 in relation to the pinion going up is "Counter-rotation" to the tire.

[@KevinWilsonSBC]

Nobody thanks so much for your info! That is the term... Go fast, go straight! Be Safe!!

[@philsautobody]

Great info! I have set my rear angle but I am trying to find info on the front angles. I can't go any higher with transmission. Is the front as important as the rear? It doesn't vibrate. Thanks

[@KevinWilsonSBC]

philsautobody thanks so much for your comments and question! The goal is to avoid extreme angles as much as possible and each car is different. The front angle is important for the life of the u-joints but not sure what angle you are dealing with in your comment. Generally the transmission is set unless you can adjust trans mount more. Go fast, go straight! Be Safe!

[@frankkatsenis3812]

Thank you for the video can you explain why in physics terms the force on the driver rear pushes down and passenger rear pushes up? Also why the rear end where the drive shaft connects pushes up? Is it centrifugal force or something else? What makes it chose those directions? in the comment but if you make another video later.

[@KevinWilsonSBC]

Frank Katsenis thanks so much for your comments & questions! Checkout www.musclecardiy.com/performance/rear-axle-fundamentals-building-for-performance/ Go fast, go straight! Be Safe!!

[@cray1801]

Why do people put the heavy battery over the passenger side tire, I thought it was for more weight on that tire for better traction? On an open rear the passenger side tire is almost always the one that spins first and more. You are saying that the torque pushes the passenger side tire down so why does it typically spin first in this scenario? I know that with more force the Coefficient of friction goes up for better traction. Great video's thanks for sharing!!!

[@gregsmith9457]

👍👍👍

[@MrCbell57]

Good stuff sir. My problem is everyone is telling me the transmission and rear end need to be in parallel which means if you’re going down 2° on your opinion your transmission would have to be going up 2° which is not likely based on the intake being angled so that the carburetor sits flat on top of the motor 2° would totally change the corporation in fact so it needs to be going to degrees down if both transmission in opinion or pointed downward that is not in parallel sir. Please correct me if I’m wrong I’m trying to set the pinion on a Ford mustang 1970 and everyone says the pinion needs to be downward 2° but my Tremec Freight speed is also moving downward at 2° from the engine.

[@KevinWilsonSBC]

Hey Rick, I answered this same question from you on 2/24 on another video. Please take a look at my response to you as I explained this in that reply. If you need more help, reach out to me via email at [e-mail] and we can discuss this further. Go fast, go straight! Be SAFE!!

[@john13harbour]

Need advise... I have 69 Lincoln Mark III, and converted the transmission to an overdrive. This process required modification of the driveline, and now it seems all messed up. The original driveshaft was made up 2 double cardan joints (CV joints). This made up for the problem that the transmission is pointed downwards 7 degrees, as well as the differential pinion angle also pointed downwards 6 degrees. I also experience terribly bad vibration underneath the car as a result of improper angles. However, the modification of the driveshaft (by a shop that doesnt exist anymore) replaced the front double cardan joint with a typical single u-joint, when the driveshaft length was changed. My problem, is that i cant seem to figure out how to change the geometry of the setup underneath the car, without dumping thousands of dollars. In my mind, i have 2 options... spend a few thousand to convert to double cardan joints back on the driveshaft? or custom make adjustable trailing arms of the diff to bring it upwards, as well as cut the tunnel of the floor, to raise to the transmission. Any advice on my situation would help yall! btw, the car is fully complete rn, so my modifications mean i have to tear apart a fully painted, interiorized car. thanks

[@KevinWilsonSBC]

John Harbour thanks so much for your comments! This is beyond YT comments. I would need to see this car in person and inspect it before I could even give you some advice. Sorry man. Go fast, go straight! Be Safe!!

[@leomelton3243]

Do you aim for a negative pinion angle with a street car?

[@Streetvw548]

Hi Kevin and thanks for a great channel! I have a question for you. I been told that you allways have to take the front yoke angel in consideration when you set your piniong angel so they both are in alignment with each other. Otherwise you get vibrations in the driveshaft. Is this wrong?

[@KevinWilsonSBC]

Streetvw thanks so much for your question! For most drag cars the transmission output shaft is generally not much higher than the rear end, but if it is much higher to the point of putting the front of the drive shaft in a bad angle, you need to definitely consider that. The goal on a drag car is to keep the centerline of the crank, through the trans to the pinion to be as close to 0 in relation to each other under full acceleration which will provide the best life and performance for your u-joints. Of course, that is a perfect world with a low center of gravity, so sometimes you have to adjust based on your setup. Hope this makes sense. Go fast, go straight! Be Safe!

[@bryanmorris7052]

No matter what kind of angle the driveshaft is on , , if your trans output shaft and rear pinion shaft are on the exact same plane (angle) , you have 0 pinion angle.. A big difference in heights will promote more driveshaft angle

[@Streetvw548]

@@KevinWilsonSBC Thanks for you answer. Yes, that makes sense. I just realise that is a different approach when you are talking about a streetcar chassi och dragcar chassi. Im new to building a dragcar and i just finish my first backhalf and now doing test n tune on an old military airstrip. Once again thanks for your answer an for a grear channel. Best regards Markus

[@glenngeddes6079]

Hi Kevin. On a ladder bar car would you suggest installing a anti-roll bar? Or does it not need it?

[@KevinWilsonSBC]

An anti roll bar on the rear will never hurt, and we definitely run them on our ladder bar cars. Go fast, go straight! Be SAFE!!

[@AustinBoil]

You can leave the driveshaft out of the equation for pinion angle. It's the difference between the pinon angle & the engine/transmission angle. Measure off the balancer or motor plate for eng/trans angle. On a full chassis car it's likely pointing uphill towards the rear which means the pinion will be pointing uphill at a little less angle generally to get a -1º negative P/A for example.

[@KevinWilsonSBC]

Austin Boil thanks so much for your comments! Go fast, go straight! Be Safe!!

[@waynehorton7825]

If the crankshaft centerline is 2.5 degrees down shouldn’t the pinion point up 2.5 degrees under load?

[@TXsilvy]

What do you do in the event that the transmission output shaft sits lower than the pinion giving the pinion angle a ^ angle instead of v.

[@KevinWilsonSBC]

TXsilvy thanks so much for your question! I highly recommend you get with someone reputable and local to you to go through your scenario, especially if this is a drag car. Lot's of variables to consider, but in short, you have to compromise somewhere on your pinion angle to shoot for the best angle as possible for u-joints under load. Go fast, go straight! Be Safe!

[@jeremypike9153]

Chrysler used to use a pinion snubber. This is old school thinking you want everything in the drivetrain as straight as possible at all times resting or under load.

[@KevinWilsonSBC]

Jeremy Pike thanks so much for your comments! In a drag car you have to account for the rotation of the rear end on the hit. Therefore you plan for a straight line under load which means at rest you have some working pinion angle. Go fast, go straight! Be Safe!!

[@tylerschmitt1921]

You started to go into explain how you subtract the rear pinion from drive shaft angle but then went to talking about something else. I have a 81 Malibu and just was setting my pinion yesterday. I got 2 degrees on trans and rear end but the drive shaft is at 6. Is this going to be a issue?

[@anthonyking4387]

How close to perfect should side to side crank center line be to pinion cl be??? Please help!

[@KevinWilsonSBC]

We generally shoot to have the crank centerline within .25" - .5" of the pinion centerline depending on the wheelbase. Go fast, go straight! Be SAFE!!

[@waynehorton7825]

Ok so what if the driveshaft is pointing up? This is going to have to be a positive pinion angle no?

[@hackjobgarage9289]

Hey guys, I just installed a rear anti-roll bar on my LS swapped S-10 and it's not quite level (the sway bar). Does anyone think I should cut it back off and level it out? I kinda think I can adjust around it.

[@KevinWilsonSBC]

Not level is not a real big deal as long as it is not crazy off... the main thing is setting the links correctly with the driver in the car and the car race ready on level ground. Go fast, go straight! Be SAFE!

[@karlbaker1943]

What type anti roll to use on a mopar with Caltrac and split mono?

[@KevinWilsonSBC]

That is a broad question and I would need a bunch more info. I recommend you give Marty a call at Merillat Racing and he can help guide you and his stuff absolutely works! The ARB must be able to handle the weight of the car and the HP/TQ levels. Go fast, go straight! Be SAFE!!

[@matthewvarnam4302]

At 11:50 you say that the driveshaft spins clockwise if that's so then how does the rear passenger side tire drive into the ground...I'm just confused.

[@KevinWilsonSBC]

Matthew, thanks for leaving a comment. Driving the passenger side, right rear, down to the track is related to the twisting nature of the engine on the driver's side front of the chassis. When you twist the left front of the chassis up higher, harder, faster than the right front, it drives the right rear chassis over the tire harder, thus driving the right rear tire to pavement harder. Go fast, go straight! Be SAFE!!

[@mikehickman3330]

If you change the pinion angle, don't you have to change the drive ling angle? My drive line is 3 degrees down, drive shaft is 2.5 down and pinion is 6 degrees down. I trying to figure out this mess. I was thinking I needed to raise the diff 3 degrees to make it in line with the transmission to stop vibration, but that will only give .5 pinion angle? Don't really want to shim the transmission. Not sure what to do.

[@KevinWilsonSBC]

Hi Mike! This video is one of the best. kzbin.info/www/bejne/oJLEhayCZZ5siKM The goal is to have some pinion down angle, but if you have a motor/trans angle that is competing with that like you do, you have to compromise. When you launch and make a pass, you need the two centerlines parallel (engine centerline and pinion centerline). In your situation, I would try to get the engine/trans angle to around 1 degree down going to the rear, then have my static pinion angle around 1 degree down (down meaning going to the front of the car the pinion yoke is pointing to the ground/track). That way on the hit if you have 2 degrees of rotation on the pinion, then your centerlines will be parallel. If you have more rotation than 2 degrees, then adjust accordingly. Go fast, go straight! Be SAFE!!

[@keysautorepair6038]

Leaf spring car 6-8 is what I have always heard?

[@KevinWilsonSBC]

Camaro Drag Racing Second Generation thanks so much for your comments! It really depends on the amount of twist the rear end is going through on the hit and run. We have had leaf spring cars with ladder bars only have 1.5 degrees and that was all that was needed. Go fast, go straight! Be Safe!!

[@7080nik]

Kevin, I was always told that 0 pinion angle is un-desirable. You should always have at least a half degree even under full load. T or F?

[@KevinWilsonSBC]

7080nik thanks so much for your question! You can ask 5 racers about pinion angle and get 10 different answers. I would not fret over a .5 degree, but my goal is to have the pinion and driveshaft inline under load. Checkout this video of a great example of how a pinion angle changes on a 200 MPH 1/8th mile pass: kzbin.info/www/bejne/p2nIaqNrir6ardk Go fast, go straight! Be Safe!!

[@0lddragracer426]

This is how I've set up the drive line angle on every race car I've ever built. I've never had a problem. But the purists are posting video's saying the engine angle has to be parallel to the pinion angle. They say drive line u-joints are not supposed to be in a perfectly straight line, because the needle bearings and what ever aren't designed for that. I don't happen to agree with that. The 1.5 to 2 degree negative angle on the pinion for a race car I can agree with because of the rear-end twist under power. What I want to know is, how do you set all this up with leaf springs in the rear for a 5-600 hp big block in a pickup truck?

[@KevinWilsonSBC]

Michael Steinberg thanks so much for your comments and question! Around 4.5 to 5 degrees. Go fast, go straight! Be Safe!!

[@jeremypike9153]

The more pinion angle you get the more parasitic loss there is in the drivetrain. Its exponential as well the higher the angle the more loss exponentially not linearly. Pinion angle is the main reason manufacturers now use just a differential and CV axles. Because the pinion angle doesn't change much at all with that setup the parasitic loss is very minimal.

[@jeremypike9153]

Think 9" ford in a 300 hp car versus a normal differential in a 300 hp car. The drive angle inside where the pinion meets the ring gear on the 9" is a parasitic loss. Holds together very well for drivetrain shock and shear strength but the position of the pinion on the ring gear causes a big power loss that needs to be made up by the engine. Versus the normal positioning on a different axle.

[@KevinWilsonSBC]

Jeremy Pike thanks so much for your comments! Go fast, go straight! Be Safe!!

[@mxguy2438]

You're using the wrong word for what pinion angle is and adding to the confusion about what it is and how to set it. What you are calling pinion angle is the rear universal joint operating angle. The limits on ujoint operating angles is set by the ujoint manufacturer usually from .5 to 2-3 degrees. Deviate and you make the ujoints weaker and less efficient. Pinion angle is something else. There is a relationship between the front and rear u joint operating angles where they must be near equal and opposite. The front ujoint actually travels through an elipse shape at the driveshaft side. This accelerates and decelerates the driveshaft as it moves through 360 degrees of trans output shaft rotation. Keeping the ujoint operating angle close to equal and opposite at each end of the driveshaft cancels out this acceleration at the pinion and prevents vibration and damage. So pinion angle is all about the relationship between the front and rear universal joint operating angles. It is very simply measured by zeroing a cube style digital angle finder on any horizontal or vertical surface of the engine or transmission (like the bellhousing flange), so that the display can be read from the drivers side of the car. Now, take a measurement from the front of the pinion yolk, again with the display oriented so it can be read from the drivers side. The number displayed is your pinion angle. Your objective is for this number to be zero under load to maximize the strength of the parts along with the efficiency of the drivetrain and to minimize any vibration. High powered leaf spring cars can take quite a bit of pinion angle to achieve this which can put the rear ujoint operating angle outside of the manufactures recommended range, IRS cars are the other end of the spectrum. They require relatively little. Note there is a dynamic you should consider depending on if the car squats or lifts and the suspension type. Using ujoint angle to create "bite" is actually just making the drivetrain less efficient and reducing tq to the wheels.

[@KevinWilsonSBC]

MxGuy thanks so much for your comments and detailed explanation! Go fast, go straight! Be Safe!!

[@kevinchristianson5433]

Be careful with your terms. The Pinion Angle percentage does not (Or should not) have anything do with the angle of the driveshaft. Technically, you are referring to "working angle". The working angle is the DIFFERENCE between the pinion angle and the driveshaft angle.

[@KevinWilsonSBC]

Kevin Christianson thanks so much for your comments and correction! You are absolutely correct. Generally when talking about "pinion angle" in the drag racing community we are mainly talking about the working angle by which the u-joints are subjected to under load, not the actual Pinion Angle in the differential. The working angle is absolutely the correct term. Of course, whether the angles are following the same slope directions or opposite directions determines if you subtract or add the two angles together. Go fast, go straight! Be Safe!!

[@kevinchristianson5433]

@@KevinWilsonSBC Love the vids! keep up the good work!