From my understanding,

There is on average a 20% loss from stated hp/tq numbers to the rear wheel numbers. Is there any reason I should think this figure would be different with an L?

I found 8 different dyno runs, from our site, with stock Lightnings.
average 355hp, 427ft/lbs

so unless the 20% loss is incorrect, would it be safe to assume from these averages, that stated numbers should be closer to 444hp and 533 ft/lbs.

Help me see the light,
or correct me if I am missing something here,

thanx
Iron

 

I believe Gregg Evans has stated the loss in these transmissions is a very low 11%.

 

20% is not the correct number to use...

The conventional wisdom is that the drivetrain losses 20% in an automatic, but that's a very outdated figure according to Greg Evans.

"In a Lightning at max torque in 3rd gear (only way to measure it right) it's 11.2%"

 

We've been through this before.

The 11.2% is for the transmission, to that you have to add the losses in out dump truck sized differential and also tire friction losses on the rollers.

20% is probably conservative.

 

And remember that many of us believe the factory 380 HP rating to be conservative to say the least. Like the 305 HP Trans Am my wife has that totally stock made 297 rwhp; doesn't add up!

Jody

 

This is always a hot topic on any forums. Here are "my" suggested numbers, based on what I've seen on my own dyno, and going off customer data from engines dynoed out of the vehicle....

Manual trans with live axle- 10%

Manual trans with IRS - 12%

Auto trans with live axle - 15%

Auto trans with IRS - 18%

For our trucks, it would be 15%. From my experiance, these are the closest "average" precentages you can use.

 

Now"IF" people would only READ this and comprehend it.

 

Thanx for the replies guys,


So based on an average 15% loss, we are roughly talking
415hp 500ft/lbs at the engine

Makes you wonder why Ford used much lower conservative numbers.

I am not complaining though



Iron

 

Probably for insurance reason's. Chevrolet used to de-rate their engines' #'s back in the late 60's for that reason (I forget the horsepower numbers). Just a thought.
Bryan