rear wheel horsepower

Dunno. As for driveshaft losses, remember the loss is in the u-joints, not the hollow pipe.... and we have four in our halfshafts so I'm not surprised to find a similar drop-off. Comparing two different types of dynos on different days is useless as far as accuracy is concerned. Good dyno operators make a 'calibration' run, then a pull, then another pull, then a back-up calibration run, all before they decide what fudge-factor to use in their software. IMHO, dynomometers are comparative tools for an engine, that day. You make a run, change carbs or a cam and make another run. The horsepower change is probably a valid number but the absolute horsepower value may not be.

I would say not many 4.6s could put out 400 rwhp without some serious work(or a power adder), considering the new supercharged ones routinely put about 360 to 370 at the rear wheels. As far as your LS1, with 20+ years of development it should be stronger than a cleveland in semi stock form. I do believe however that these motors have great potential but the majority of the Pantera owners seem to be happy with the close to stock performance.(not me)I think a 351C with a hydraulic roller cam, the right intake and a free flowing exhaust should easily make over 300 rear wheel horsepower. Mine with a non-roller hydraulic cam, two plane intake and GT-S exhaust(and a valve spring or ignition problem that won't let me rev past 5800) runs 107mph in the quarter. I will dyno it soon but at the approximate weight, this equates to about 300 rwhp.Sorry to ramble.

You are right that a 4.6 would need an alot of very expensive work to put down that kind of hp. I think the dyno test was very high for a 4.6. That's why I brought up my ss camaro dyno. There are lot's of 4.6 cobras I've run against, none stock. I lost to one that had gears, blower and too many add ons to list. I considider my pantera quick, and enjoy the car every time i get into it. I just read about all these different dyno numbers and it makes me curious as to why such a difference.

Is the HP loss comparable to other sports cars or is the driveshaft loss more severe with a Pantera, thoughts?

Considering myself young and not as knowledgable but with physics fresh in my mind. I believe 100hp lost is not common with the pantera.

Reason being that we are tryign to turn power that's inline (engine) and changing that power 90 degree to the wheels really chuck a lot of the power thru the drivetrain. The ZF tranny has to be built strong enough to withstand the power these engines put out and has to be strong enough to change the power direction from the engine to the side to the wheels.

Most of the mid engine rear wheel driven cars such as the Acura NSX doesn't display this type of power lost because the engine and the transmission are both side by side so the engine rotates the way how the wheels are suppose to rotate, there's no need to change the power into a 90 degree angle to drive the wheels so there's not as much power lost in the drivetrain (U-joints, shaft, weight or etc.)

I might be wrong but I believe this is one of the reason why it's uncommon to see the pantera have about 100hp difference between the engine and the rear wheels.

I have yet to dyno my pantera, but the only thing that has been done to it is an aftermarket cam that shoots out most of it power from 3500rpm and up.

I just have to find myself and aftermarket flywheel and clutch system now since the throw out bearing failed on me and might as well change the other steock units while I have the transmission off. Do you guys think an aluminum flywheel is okay for a street driven pantera?

Larry

If you have a 100 hp loss in the transmission, i think you coulden't drive more than 40 miles before your transmission and/or rear axles would serious be overheated.

Paul.

Paul,
We have overheated the ZF in a BMW M-1 with a 450 hp straight 6. In a long distance race.
There is no loss of 100Hp cruising down the road. But the problem shows up under full throttle, during one long straight after the other. This type of race takes ZF oil cooler.
I do not know, but when comparing axel vs. rear wheel hp. Most often an engine show more hp in the bench than installed in the car. Other mufflers, accessories etc.
So, all those losses might not be caused by the ZF. It seems too much.
Goran M

Goran, I agree with you, and what you say is is also what I mean or tried to say, in only a few words.
The loss of power is depending on much more than just the transmission.

Paul.