I was woundering if any body could give me an at least close % or tell me how I could find it. On how my tq and hp is lost in the transmission, transfer case, drive shafts, and front and rear ends, and tires. such as a th-400, np 241, drive shafts from an ext cad long bed and 4.11 gears, with 35s. please help or tell me were I could find this usefull info. thanks :smokin:

I am assuming you have a FF 14 bolt rear. I would guess 20% loss in 2WD and closer to 30% in 4WD.

Well, most of those are negligible losses. The biggest one you should worry about is that damn TH400. That is good for 150hp loss IIRC.

so what your sayin is a 3/4 ton with a 350tbi and th400 will see like only 10 horsepower to the ground in 4wd? 210hp @ flywheel - 150hp from th400 - 25hp from axles - 25hp from 35" tires? god forbid the poor sucker turn his air on in oxygen deprived 90* temps!

TH400 power loss is nowhere near 150hp, estimates Ive seen say 50-60hp.

The biggest one you should worry about is that damn TH400. That is good for 150hp loss IIRC.

That is such bull shit.
Your going to loose 7-10 HP in your pumkins (each)
maybe one in the driveline but even with a long bed it is neglagible
T-case is going to be comprable to the axles but a bit more, maybe around 25?
Trans you will loose a few, as much as 45?
I figure your looking at a net loss in 4 wheel drive of as much as 70+HP.
Simple cures for that is switching to full synthetic oils, you might be able to pull 15 HP back out of it, maybe a bit more but not much.
HP loss in the tires is also not really worth consindering.

Of course, as you know, gearing is the cure to these problems, lower gearing will allow you transfer that torque to the tires.
Why?
What are you building?
If your looking to spice up your rig.
Get rid of the stock exhaust manifolds for some headers, opening up the exhaust will give you a good 10% increase in torque and really improve your throttle response.
Also a cold air kit will spice up your engine as much as another 10%.

And as for the T-400. IMHO, that is the most kick ass auto tranny available. Dont get rid of that bad boy, you will probably never break it if you build it right.

For 2wd cars, I guesstimate 15% loss for manuals and 20% for autos. I've never measured or heard of any 4wd(truck) numbers.

Regarding the thm400 loss, I seem to recall 45-55 hp loss. But I positively remember the worst: 65 hp loss thru a C6!

Feel your tranny or axles after an hour on the highway to get an idea of the hp wasted and turned into heat.

You're never going to cure driveline power loss unless you actually make it so the motor never has to turn any mass or overcome any friction. Bearings have to preloaded to last, turning them takes some energy. Gears don't add power, they just give you a bigger lever. You run out of top end if you go too deep.

As for the Th400 being the best auto ever, it is tough but its got some large drawbacks. No OD, meh 1st gear, lots of drivetrain loss, oh and its a heavy piece of machinery. Those new 6l90e's look pretty sweet, awesome ratio's, rated to hold as much as a 4l80e. Transplanting will provide some hurdles but for the gain Im sure it will be done.

Thanks guys, I just wanted to acutually see some numbers I have a new project in mind. It is a 93 single cab long bed with a 5 speed and 4.11s. It had a 6.5 and Im trying to decide on a moter to putin it. Either a bb or a sb. I was thinking probly 300 hp. I wanted to see the % of lose so I can get 300 hp to the ground.