Dynojet Run 609 RWHP

[Shaker1]

lol - how did I know somebody would get "all technical" on me for rounding off.

See, 662 *.15 = 99.3, so I simply use +100 HP as the adder from RWHP on the '13 - easier huh? ...especially when you see dyno numbers varying over 30 RWHP and some of the difference is a 10+ HP "spike" near the peak. No need to split hairs, this car is making 20+ HP more than the upgraded SAE rating. Anybody who complains about these numbers needs their peepee smacked. :lol:

OK, I certainly do not want my peepee smacked by the bailiff! A lot of folks seem to multiply by 1.15 instead of dividing by .85 to get estimated crank HP. But, point taken. :beer:

 

[GT Premi]

... A lot of folks seem to multiply by 1.15 instead of dividing by .85 to get estimated crank HP. ...

Unfortunately, they're doing the math wrong. Let's use 100HP for simplicity's sake.

A 15% loss on 100HP is, obviously, 85HP at the wheels:
85 * 1.15 = 97.75

As you can see, that is completely wrong. In that equation, 85 is being treated as the whole whereas it really isn't. Eight-five is just 85% of the whole 100HP. The equation above is basically saying 85HP plus 15% of 85HP. Again, that is completely the wrong formula to use. The correct formula to use is:
85 / 85% [100% minus the 15% assumed drivetrain loss] = the whole

In other words:
85HP / .85 = 100HP

So for future reference, everyone, if you want a more accurate number of what you think your crank HP is based on your RWHP, divide your RWHP by the assumed percentage you think you're getting at the wheels. So if you think you're loosing 15%, you would divide by 85% (100%(crank) - 15%(assumed loss) = 85%).

 

[Bob Cosby]

Ya, the other problem is the "assumed percentage" deal. But I guess I'll not delve into that can of worms again, as it is a no-win arguement.

 

[500_man]

Here's a '13 GT500 making 633.8 RWHP after a Jon Lund tune (was 584 stock.)

2013 Shelby GT500 Custom Tune Dyno - YouTube

 

[90goldtsiawd]

Here's a '13 GT500 making 633.8 RWHP after a Jon Lund tune (was 584 stock.)

2013 Shelby GT500 Custom Tune Dyno - YouTube

Should be noted this was on a Mustang Dyno and not a Dynojet.