drive train losses

[Cody Forbes]

>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.

Heh, yeah oh and Mike I did replace that crankcase vent hose that you
pointed out!

>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."

I actually got in this argument about losses myself, and I was even on your
side Mike, with some friends not more then 2 months ago. I heard them say
something about a percentage, and I said I didn't believe it, I would say it
was a constant number. In the end I was showed a link to a website though
where a guy took a supercharged Mustang and dyno'd the engine at a few
different boost levels, then stuck the sucker on a chassis dyno at the same
various boost levels, and it did turn out that more power caused more loss.
I can't find the link, but I'm still looking. Chassis dyno manufacturers use
standards to calculate HP, like a standard air temp and such. Some dyno's
will use a standardised drivetrainloss percentage to tell you flywheel
power, and that standard for AWD is 20% (RWD I think is 12%, FWD 16%),
others will do a coast down test. Standards though don't usually work in the
real world, which is why I said in my origianal post I'm not really sure
what my loss is, but according to the standard I have XX power.

>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 . . .

Heres the trick. Engne displacement is effectively increased with boost. At
2.0bar absolute pressure you have effectively nearly doubled your
displacement. I know that again this isn't an exact science, but it's
roughly true. You could say then that my engine would be about 310ci when on
boost. I have a few magazine articles of 500+ hp 5cyl engines in every day
driver cars too, check them out @
http://www.blackforestpics.com/gallery/Codys_Audi_-Stuff. They are both
right towards the top of the list.

But heres how to solve this one. Mike when I come up there sometime within
the next two weeks I'll take you for a ride and you can decide for yourself
while you are trying to figure out how to pick your head off of the back of
the seat ;-D!

>Best Regards,
>Mike Arman

-Cody Forbes