power loss with increased drive shaft angles

[ontherun]

I'm running a WH lift, 3.5" in rear 3.5" prerunner springs up front stock radius arms, I had double shocks all around but now have singles cause the ride was terrible (Rancho shocks now, hopefully bilsteins sooner than later).

ok, you all brought me around. My truck will always be a 40 year old truck, no sense in trying to get it any faster. Makes sense to stick to the plan and develop it for what it was built to do, go offroad. I was just concerned about freeway saftey when I considered lowering it, guess I just need to get the cage in, fix the steering, and drive slow.
Daniel

You know what would be good though?,.. if ya' go work for an Italian car maker,.. or German/Austrian car-maker 'cause your style would be their "forte' :;D ;D S.

 

[trailpsycho]

I cant speak too much from experience...yet...as I have nto had my truck on the road with the 35s, 5.5" of lift, long arms, etc. But with a 2.5" lift, duals or singles (shocks) and the proper tie-rod linkage/steering set-up I could run 80+ at will on the interstates and it handled well. I CANT imagine that your 3.5 " lift would be that scary or dangerous; unless your steering is not up to par....and thats just plain scary and dangerous. These are things you can improve on to give you the best all around ride on and off-road (and dependable off-road)...sucks being stuck off-road without steering. We had a guy in our group last year at the Bandlands who lost power and had hydro-steering...the truck was rolled while trying to get it back to the trailer, b/c he couldnt steer it to keep up with his tow. Turned a good day into a bad one really quick.

 

[dbridgs]

there you go, the world needs a broncoghini or a ferarri-onco ;D

anyways, I think most of my poor handling is coming from slop in the steering colum. I can get like 1/8 of a turn at the wheel with no input into the steering box. I've looked at it and can't figure out what it is. Makes me want to replace the whole fandangled colum and upper shaft with a simple rod (like a race car type set up).

 

[Broncobowsher]

Laws of physics. energy cannot be created or destroyed.
If you are losing 20% to a single U-joint, then that 20% has to go somewhere. the only place it can go is heat. So 50 HP to keep a Bronco moving down the highway on flat ground (guessed number based on 20 something for a normal car and we have a brick) That would be about 10HP of heat, or over 7500 watts of heat that the U-joint would be taking on and must disapate. Just can't be. That much heat and it would be glowing orange in less then 10 miles.

 

[ontherun]

there you go, the world needs a broncoghini or a ferarri-onco ;D

anyways, I think most of my poor handling is coming from slop in the steering colum. I can get like 1/8 of a turn at the wheel with no input into the steering box. I've looked at it and can't figure out what it is. Makes me want to replace the whole fandangled colum and upper shaft with a simple rod (like a race car type set up).

Sounds like Billet might satisfy your astuteness,..... hey! it'll match your Bilsteins!!;D S.

 

[Socal Tom]

there you go, the world needs a broncoghini or a ferarri-onco ;D

anyways, I think most of my poor handling is coming from slop in the steering colum. I can get like 1/8 of a turn at the wheel with no input into the steering box. I've looked at it and can't figure out what it is. Makes me want to replace the whole fandangled colum and upper shaft with a simple rod (like a race car type set up).

Mine used to have some slop in the collapsable section. I put a tack weld on it to keep it from moving. It was small enough that it should break if I ever hit the wheel with my chest.
Tom

 

[dbridgs]

Broncobowsher, I really like that reasoning, seems pretty conclusive to me, thanks.

Socal tom, I was thinking of doing the same thing since there doesn't seem to be any other place the slop could come from, where exactally did you tack it. Did it make a big difference?

Is the colum supposed to collapse at the slip joint in case of an accident?

Thanks

 

[trailpsycho]

ALot of times there is also slop in the box. I would replace the lower shaft or put new u-joints in it...I found it was not that much more to just buy a whole new HD shaft (WH and JBG sell them). IF you then still have issues with slop, send your steering box to PSC or WTO. WTO is a little less expensive. They are very nice; most reviews are very positive...I have not had a chance to use the box since, but it seems very tight since the rebuild. Good luck.

 

[45acp]

Think of it like this-

You have an Early Bronco at stock height with 31" tires and a 300hp 302. You run down the 1/4 mile track and it runs a series of mid-15 second runs. You then pull it around behind the track and install a whoever brand 3.5" lift and leave everything else as-is. You get back on the track and run another series of mid-15 second passes.

There is no torque loss with minor pinion angle changes.

 

[Socal Tom]

Think of it like this-

You have an Early Bronco at stock height with 31" tires and a 300hp 302. You run down the 1/4 mile track and it runs a series of mid-15 second runs. You then pull it around behind the track and install a whoever brand 3.5" lift and leave everything else as-is. You get back on the track and run another series of mid-15 second passes.

There is no torque loss with minor pinion angle changes.

Well look at it from the other extreme. If you want to climb a rock with your front tires straight ahead, you get full power to the wheels. If you try to climb that rock with the wheels turned full lock, you may bust a u-joint because it can't take the stress. Between those two extremes, there is some loss of power to the wheels. I agree though that the 2 or three degrees change in driveshaft angle creates a meaningless loss, but if applied to the D44 u-joints in the axles it can help explain why u-joints pop at full lock.
Tom

 

[Devin]

If you are losing 20% to a single U-joint, then that 20% has to go somewhere. the only place it can go is heat

It can also go into deformation (elastic or plastic) as well as creation of a fracture surface (refer to Tom's recent post).

 

[00gyrhed]

torque losses

This was actually a question on a Mechanical Engineering Dynamics exam I had 30 years ago. Unfortunately it is typical of the way all engineering schools teach engineering. Most of the people teaching couldn't engineer themselves out of a wet paper bag with a razor sharp pocket knife and the instructions written on the inside of the bag.

Old time auto engineers actually used to worry about it and tried to make everything line up. Ever look under a model A Ford? At least that is what I was taught by the guy who couldn't speak English and wrote on the board in English French and Arabic at the same time.