Yes, but only during real-world acceleration. You would not see
inertial losses on a chassis dyno.
Cale
Stlaurent Mr Steven wrote:
>
> Less inertia means less HP lost. There seems to be a 10-22 percent lost to
> the rear wheel due to the transmission, drive shaft and rear gearing.
>
> Another thought is the shorter the drive shaft less flexing on the shaft to
> produce rear wheel HP.
>
> -----------------------------------------------------------------
> Steven St.Laurent
> Test Engineer
> Test Branch, GSD,MCTSSA
> MARCORSYSCOM, US Marine Corps
> mailto:stlaurents@mctssa.usmc.mil (work)
> mailto:Saint1958@home.com (home)
> Office: (760) 725-2296
>
> -----Original Message-----
> From: Mike Schwall [mailto:mschwall@flash.net]
> Sent: Thursday, February 03, 2000 12:06 PM
> To: dakota-truck@buffnet.net
> Subject: Re: DML: Drive shafts. Very weird.
>
> At 11:01 AM 2/3/2000 -0600, you wrote:
> >Hey Dester,
> >
> >Do you have a steel 2-PIECE driveshaft, with a CV boot type thing at the
> >joint? If so, lookout! The boot has been known to grenade at speeds
> >over 90 mph, and the one piece, NASCAR approved aluminum shaft is DC's
> >fix. Anybody's head hurt yet? Here we go...
> >
> >The aluminum shaft may not provide any gain over the steel one - it's
> >all about second moment or inertia, or how much energy it takes to "spin
> >up" something. A shaft with a larger OD will take more energy to spin
> >up to a certain RPM than a smaller one, given they are the same material
> >and wall thickness. The larger shaft, if made of a light enough
> >material may have an second moment equal to the smaller shaft of heavier
> >material.
> >
> >So what I'm saying is that the larger diameter aluminum log may not free
> >up horsies compared to the smaller diameter steel unit.
> >
> >Yah?
> >Cale
> >98cc318sporty
>
> Wheels are turning.... I see your angle, but even if the aluminum is
> thicker, it is still lighter than the stock steel. So the rotational mass
> of the aluminum is still less than the smaller steel, so the force required
> to overcome the inertia is still less, thus allowing more horses to go to
> the rear end. Ever seen carbon fiber driveshafts. They have a large OD,
> but they are extremely light and strong. Less rotational mass (weight),
> less affect by inertia, less power wasted turning the driveshaft.
>
> Mike
>
> __________________________
> mschwall@flash.net
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