Pinion angle vs. horsepower

[jtscuba02]

I have seen it mentioned a few times that if the pinion angle is off, it could cost you 10hp(?) per every degree. Does anybody have a link to some proof of this? I'm not doubting anyone, I would just like to see some actual tests to prove it. The theory makes sense but I'm not the smartest guy in the world, and sometimes things have to be broken down barney style for me. Thanks, jt.

 

[stkjock]

that's a new one on me

 

[Preston951]

Never heard that before, but if its true, holy shit.

I really don't see how it could make THAT huge of a difference. Most likely drive-ability and sound/vibration issues but I doubt 10hp/degree.

 

[jtscuba02]

that's a new one on me

I spent a good portion of my day, well maybe just a couple hours, trying to figure it out. I had never heard of this until I saw it here, so maybe it was a joke that I didn't catch.

I watched 5 videos on setting P/O and none made mention of a lose of rwhp. Also none of the driveshaft mfrs have it on their websites.

 

[stkjock]

I could see it costing you ET as your traction would suffer, but not HP, just doesn't add up.

 

[JeremyH]

Swap from stock springs to lowering springs on the dyno and find out lol

 

[jtscuba02]

Swap from stock springs to lowering springs on the dyno and find out lol

Care to elaborate? Thanks, jt

 

[JeremyH]

Changing ride height in the rear will change pinion angle on the ds.

Meant it as a joke, but that would be an easy way to see if pinion angle effects dyno numbers dyno the car then dyno it lowered.

 

[jtscuba02]

Changing ride height in the rear will change pinion angle on the ds.

Meant it as a joke, but that would be an easy way to see if pinion angle effects dyno numbers dyno the car then dyno it lowered.

Ahhh, gotcha(about the joke). I can understand if the pinion angle was off it would cost power, but it seems it would have to be way out and losing 10hp would be the least of the problems.

 

[JeremyH]

I've never heard this pinion angle costing power thing or seen any examples of it.
The stock pinion angle is changed when the rearend suspesnion geometry is changed ie by lowering your car. You can use an adjustable uca to get back to stock angle. Were talking 1-2 degrees max change if u drop the rear 2 inches. Its not gonna have a loss in power to the wheels. It can effect traction at the drag strip supposively but i am lowered an inch and ahalf with a fixed length uca and one piece alum ds, and see no need to adjust anything.

 

[JeremyH]

And although i meant it as a joke as the pinion angle change of 1-2 degrees isnt gonna effect power output. You could dyno on stock springs. Swap to some lowering springs and dyno again and measure the change in pinion angle and see if theres a change.

 

[bigwilly43729]

I totally know it's coming from left field, but perhaps through some serious vibration you could lose X amount of energy that's being transfered to the wheels. I'm not physics major and I've had a few right now, but I guess it's an idea.

My car didn't feel any different in terms of how it launched even when I was getting vibes at 65mph, nor at 90 or 120mph.

 

[jtscuba02]

I totally know it's coming from left field, but perhaps through some serious vibration you could lose X amount of energy that's being transfered to the wheels. I'm not physics major and I've had a few right now, but I guess it's an idea.

My car didn't feel any different in terms of how it launched even when I was getting vibes at 65mph, nor at 90 or 120mph.

I can see how in some extreme cases you could lose hp due to an extreme difference in angles, something like a lifted vehicle(think jeep). But I don't think so with mustangs and all of what, a 2 inch drop.

Look at Van Wilder's thread about his dyno numbers and you will see it mentioned there.

 

[JeremyH]

Yeah unless you running in ridiculous amount of degrees off like 5-20 in lifted truck and jeep applications you arent going to see adifference. I think all the hype over correcting a pinion angle change of 1-2 degrees for lowering is over rated.

 

[smoken1986]

Yeah the only way I could see any possible way you could get power loss is if your angle was + to many degrees and the pinion bearing was not getting oil. That could cause it to overheat and expand drawing some power but of course not long after it would destroy the bearing.

 

[don_w]

I think all the hype over correcting a pinion angle change of 1-2 degrees for lowering is over rated.

Not if you're drag racing. I'm not saying it robs power, but it does have an effect on planting the tires.

 

[JeremyH]

Not if you're drag racing. I'm not saying it robs power, but it does have an effect on planting the tires.

Yeap i get that and can understand for a 60ft drag thing pinion angle and lca angles are important, see post #10. On your average street stang that sees the strip a handful of times a year like myself i didnt find it necessary to worry about pa my suspension isnt setup for launching as it is anyways.

 

[irishpwr46]

im pretty sure i saw someone other than me post that here. i could have misread it also. maybe it said it could be a loss in et equvalent to 10 - 20 hp.