drive train losses

[Mike Arman]

I do want to make one thing absolutely crystal clear in this discussion of 
drive train losses and how big they may or may not be.


I am NOT trying to rain on anyone's parade - I absolutely encourage and 
support anyone who modifies their own vehicle for better performance (as 
opposed to just putting stickers and plastic wings on it), and anyone who 
is successful has my complete admiration - this is NOT easy and it is NOT 
cheap, and they have put their money where their mouth is . . .

I've seen Cody's 5000TQ - it runs really, really well, sounds terrific, and 
is a good job. I applaud his enthusiasm. I like his car.

My objection in this entire discussion is to unsubstantiated HP figures 
based on erroneous and totally arbitrary "percentages of HP lost in the 
drive train."

Big numbers sound great, but lets be realistic - a 140 cubic inch SOHC 
engine with 10 valves per cylinder is NOT going to put out 500 hp for very 
long (if at all).

If the numbers were correct (remember, that is 3.6 hp per cubic inch), my 
V8 should produce 780 hp out of the 216 cubic inches - and it has quad cams 
and 32 valves (but isn't turbo). Five liter fords should make some 1,080 hp 
. . . nah . . .

My point is this - the dyno measures what comes out at the drive wheels - 
and then adding an arbitrary 20 or 25 or 30% "for losses" is simply 
incorrect, and does not do justice to the effort, expense and skill of the 
person who modified the engine.

It *sounds* good, but if I had to classify the statement, I'd say it was an 
automotive urban legend, nothing more.

Best Regards,
Mike Arman