Found this rwhp to crank hp conversion - LS1TECH - Camaro and Firebird Forum Discussion

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# Found this rwhp to crank hp conversion

 05-27-2008, 12:06 AM #1 Teching In Thread Starter iTrader: (3)   Join Date: Jun 2006 Location: omaha nebraska Posts: 30 Found this rwhp to crank hp conversion I have already been pwned for believing everything I read on the internet, so.. I just wanted to know if anybody knows how far off this is? Or if it is pretty close. I was just bored and curious to see what my car puts down at the crank. According to this my 482rwhp puts down 583! That is 100hp difference! If this is true, I need to get some suspension/ rear end work done ASAP! correction factor to convert rear wheel HP to crank HP is 1.21, or about a 17.2% loss. Given that, my numbers would work out as follows using the equation RW * CF = C, where RW is rear wheel HP or Torque, CF is the above correction factor, and C is the crank HP or Torque.
05-27-2008, 01:48 AM   #2

Join Date: Jun 2007
Posts: 2,346

Quote:
 Originally Posted by tacohen01 I have already been pwned for believing everything I read on the internet, so.. I just wanted to know if anybody knows how far off this is? Or if it is pretty close. I was just bored and curious to see what my car puts down at the crank. According to this my 482rwhp puts down 583! That is 100hp difference! If this is true, I need to get some suspension/ rear end work done ASAP! correction factor to convert rear wheel HP to crank HP is 1.21, or about a 17.2% loss. Given that, my numbers would work out as follows using the equation RW * CF = C, where RW is rear wheel HP or Torque, CF is the above correction factor, and C is the crank HP or Torque.

Power at the wheels is the best way to measure, why convert it back to the flywheel like the factory does? Your math is close but depends on what transmission as the A4 obviously eats more than the M6.

 05-27-2008, 02:18 AM #3 Teching In Thread Starter iTrader: (3)   Join Date: Jun 2006 Location: omaha nebraska Posts: 30 When I tell people what I have, I obviously go with the power to the wheels. Like I said, I was just curious and bored at work looking stuff up. It is kind disappointing when you look at the power you lose through the drivetrain. I have a M6 btw.
 05-27-2008, 03:17 AM #4 8 Second Club iTrader: (5)     Join Date: Aug 2007 Location: Detroit Posts: 911 torque converters with big stalls, heavy driveshafts (chromeoly) and gears, and big rearends eat horse power as well. That calculator is about as good as a guess. I put down 462rwhp, I gues my motor makes a bit over 500... it dont matter man. All that matters is the end result.
05-27-2008, 08:08 AM   #5
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Join Date: Dec 2002
Location: Chattanooga,TN
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Quote:
 Originally Posted by 1BDTRAM torque converters with big stalls, heavy driveshafts (chromeoly) and gears, and big rearends eat horse power as well. That calculator is about as good as a guess. I put down 462rwhp, I gues my motor makes a bit over 500... it dont matter man. All that matters is the end result.
That's true, may car put down 432/390 unlocked on a really stingy mustang dyno and I was really disappointed, until I went to the track. It busted off and 11.08 on the very first pass with a crappy 60' time with a full weight car only change was the tires. You would think my car made a little more rwhp because of the time it ran but I really don't care I know it will be in the 10's if I get the 60' time down. So the the morel of the story is take it to the track and see what it does. I love telliing guys around here my car only made 432 rwhp because it pisses them off when they see my times.

 05-27-2008, 02:14 PM #6 TECH Enthusiast     Join Date: Apr 2005 Posts: 678 Well I put down 351rwhp on my stock 01 Z06. If the correction factor is accurate then I have a 424hp to the flywheel. My 385hp motor was very underrated then.... Hmmm....

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