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tricky power and torque question

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  #1  
Old 02-19-2008, 06:44 PM
freegeek's Avatar
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Default tricky power and torque question

Generally speaking people talk about the BHP of the car, in other words, engine output power rather than power at the wheels.
Normally this is measured on a rolling road, but how does the tester know what to add on to the measured output power to get a BHP value?
Next, the RR tester will also tell you your torque, now is this the actual measured torque or once again a factored torque equivalent at the crank without any losses.
The reason I ask is that the torque reading from VAG-COM does not match up with the torque calculated from the BHP calculation of MAF/0.8. It is lower than the one I calculate.
Perhaps the vag-com torque is with the losses whereas the value I calculate is a theoretical one without losses.
I need to get to the bottom of this to know which is the correct one to show on my boost gauge below.

 
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Old 02-19-2008, 06:49 PM
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Default RE: tricky power and torque question

I do believe that the vagcom (butt dyno i believe its called) takes out 12-15% for drivetrain loss. You know that we in the US only car about whp numbers. Im not sure how people account the powertrain loss for the BHP in your neck of the woods.
 
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Old 02-19-2008, 06:51 PM
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Default RE: tricky power and torque question

What kind of magic do you have to graph stuff like you did for your vent there.... you might be able to help me with a problem I've been stuck with for a couple months.
 
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Old 02-19-2008, 06:53 PM
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Default RE: tricky power and torque question

Matt, this guy is your man. If you havent seen his thread on vortex, you need to go see it. Its the same sn
 
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Old 02-19-2008, 06:55 PM
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Default RE: tricky power and torque question

Its a small micro and a display out of a mobile phone, it graphs or shows on a gauge all the normal vag-com data, I also extrapolate for power and throw in g force measurement also for fun.
 
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Old 02-19-2008, 07:04 PM
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Default RE: tricky power and torque question

mount that in the center cluster area, and will make a fortune.
 
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Old 02-19-2008, 07:31 PM
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Default RE: tricky power and torque question

how do you read power with vagcom? I didn't know you could do that
 
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Old 02-19-2008, 07:48 PM
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Default RE: tricky power and torque question

ANYTHING the car can/has to monitor can be read/logged by you with vag-com. Just a matter of finding the right block or whatnot.
 
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Old 02-19-2008, 07:51 PM
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Default RE: tricky power and torque question

That display is pure sex.

I want one.

Bad.
 
  #10  
Old 02-19-2008, 07:51 PM
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Default RE: tricky power and torque question

ORIGINAL: eliTTe

how do you read power with vagcom? I didn't know you could do that
Block 005 http://forums.audiworld.com/vag/msgs/457.phtml
 


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