% of power loss through drive train?
Le Mans Master
Joined: Feb 2003
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From: The line waiting to see Santa Claus stretched all the way back to Terre Haute, and I was at the end, Indiana
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18
According to Mallett Cars, which did my conversion, they figure driveline loss at 17% for manual and 22% for auto. My car hits about 388 rwhp on the dyno, and is rated at about 500ghp @ crank. That's 388/.78 = 497.44, so that's pretty close. Numbers listed above are too conservative.
So, 400rwhp should be about 512hp for auto and 481 for manual.
So, 400rwhp should be about 512hp for auto and 481 for manual.
Last edited by 99mallett; May 14, 2008 at 10:26 PM.
Burning Brakes
Joined: Feb 2004
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From: edmonton ab
For a 6 speed about 450 based on a C5 Z but that would adjust slightly up if you are running a heavy wheel/tire comb.
It isn't a fixed percentage. Most of the loss is due to the weight of the reciprocating mass you are spinning which doesn't increase as the engine output increases. Only frictional losses change.
It isn't a fixed percentage. Most of the loss is due to the weight of the reciprocating mass you are spinning which doesn't increase as the engine output increases. Only frictional losses change.
Team Owner
Joined: Mar 1999
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From: San Jose/Bear Valley CA
CA Events Coordinator
Years ago we did a drivetrain loss test on a dyno. If I remember correctly after a dyno run I had to let the car wind down on its own and not hit the brake for the dyno. When this was taking place the dyno had the software to read such a thing.
On my 6 speed with 3.73 gears it was only 8.5% drive train loss. If this is true, Chevrolet did wonders for allowing us to put more HP to the ground.
On my 6 speed with 3.73 gears it was only 8.5% drive train loss. If this is true, Chevrolet did wonders for allowing us to put more HP to the ground.
Race Director
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From: Redsox, Pats, Celts & Bruins !!! Redsox Nation !!!
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
According to Mallett Cars, which did my conversion, they figure driveline loss at 17% for manual and 22% for auto. My car hits about 388 rwhp on the dyno, and is rated at about 500ghp @ crank. That's 388/.78 = 497.44, so that's pretty close. Numbers listed above are too conservative.
So, 400rwhp should be about 512hp for auto and 481 for manual.
So, 400rwhp should be about 512hp for auto and 481 for manual.
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Melting Slicks
Joined: Jul 2006
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From: Chesapeake Va
The chassis dynos the have at the Bosch shops in Germany had that capability. And thats exactly how they performed that test.
Last edited by edcmat-l1; May 15, 2008 at 12:45 PM.
Melting Slicks
Joined: Jul 2006
Posts: 3,356
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From: Chesapeake Va
According to Mallett Cars, which did my conversion, they figure driveline loss at 17% for manual and 22% for auto. My car hits about 388 rwhp on the dyno, and is rated at about 500ghp @ crank. That's 388/.78 = 497.44, so that's pretty close. Numbers listed above are too conservative.
So, 400rwhp should be about 512hp for auto and 481 for manual.
So, 400rwhp should be about 512hp for auto and 481 for manual.
Also, if you run these autos with the converter locked, the auto trans equation goes out the window. You can then assume a loss very similar to a manual.
Race Director
Joined: Sep 2005
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From: Pasco WA
According to Mallett Cars, which did my conversion, they figure driveline loss at 17% for manual and 22% for auto. My car hits about 388 rwhp on the dyno, and is rated at about 500ghp @ crank. That's 388/.78 = 497.44, so that's pretty close. Numbers listed above are too conservative.
So, 400rwhp should be about 512hp for auto and 481 for manual.
So, 400rwhp should be about 512hp for auto and 481 for manual.
Stock C5Zs, rated @ 405HP typically run about 350 RWHP, so can't we assume a 55hp drivetrain loss? And why would this loss increase as power is raised via modding? I think percentages are just a VERY rough guide to use, and even dyno readings have huge variances.
