"racespit@mail.netzero.net" wrote:
> I have heard you lose about 15% from flywheel to rear wheels, but of course I
>am sure that varies due to car, weight of driveshaft components, etc.
>
> Keep Triumphing,
> Susan :)
>
> Original Message:
> -----------------
> From: EISANDIEGO@aol.com
> Date: Thu, 9 Aug 2001 15:23:47 EDT
> To: fot@autox.team.net
> Subject: Basic Question...Expected Hp Difference
>
> What would be the typical expected % difference in hp from a engine
> tested by itself in the lab dyno verses one tested as installed in the car at
> the rear wheels?
>
> Cary
>
> --------------------------------------------------------------------
> Mail2Web - Check your email from the web at
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I did a search last night to see what I could find on the web regarding chassis
dyno hp vs. engine dyno hp.
I found four sites that said that 15 - 20% was the difference, especially for
cars of our hp. One guy said 30%.
Above is the data -- which is something separate from opinion -- and my opinion
is the 15 - 20 is right for our hp range, but I doubt that it is a
constant percentage for all horsepowers. Maybe it is, but that would say that a
500 hp Chevy loses 100 hp through the drivetrain.
Now, where are drivetrain losses? Friction in beaarings and seals, friction
between gears in trans and rear end, and loss between tires and chassis
dyno rollers.
I'd sure like to hear what a genuine dyno guy has to say about this.
--
uncle jack and New Blue
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