TB993tt

560hp @ 4500rpm
torque(in lb/ft) X revs/5252=hp

560 X 5252/4500=653lb/ft

I was going from your statement of 500rwhp @ 4500rpm.
If your stock 408hp car dynoed at 380hp then the loss is about 7% on that dyno, so 500FWHP would be about 535FWHP hence the624lb/ft

msobota

So torque as reported on a chassis dyno is rear wheel torque?

where does the 5252 number come from?

Mike

TB993tt

torque reported n a chassis dyno can be wheel or flywheel depending on whether the dyno has a correction program - I couldn't read your dyno chart very well - couldn't make out what curve was what /
The 5252 is just part of the formula - engine dynos measure torque then calcuate power using that formula.

C4TT

Hey TB do you have any clean pics of your blue beauty?

SundayDriver

Trivia content...

1 HP = 33,000 lb ft/minute of work

The ft-lbs of torque are just a twisting force - no work is actually done unless we (theoretically) make that force move some weight over some distance. So to get torque to do some work, we will move weight over a pulley that is 2 feet in diameter, which means we have a force in lbs, equal to the torque (in ft-lbs) at the 1 foot radius. We move the weight of 1 lb, over 1 revolution (to cancel out the rev component of rpm and that means the weight has traveled over a distance of 2 * pi feet.

Now 33,000 / (2 * pi) = 5252 and there is your conversion. It is confusing because we use ft-lbs for torque and lb-ft/min for work and they are not one for one - they convert with the 2 foot pulley concept.

TB993tt

So it should be 5250 then

SundayDriver

Only for your personal value for pi

TB993tt

The microsoft calculator only calculates it to 32 places