Hello Everyone,

Hoping you all can help me track down some missing HP. Here is the 411

Recently got a Gtech pro and using the RWHP calculation feature, I was only able to muster 204 RWHP.

Using the formula I've seen before (1.17) for drivetrain losses I multiplied 204 x 1.17 for 238 fwhp.

The test vehicle:

'95 base model Automatic
54k miles (not rebuilt as far as I know)
Downpipe
Greddy SP CatBack
Pettit Silicon Hose Wrap
Pettit Tune Up 2 months ago (fuel filter, plugs, etc)
Pettit Alum AST
Pettit Power Pulley
Boost pattern 11-8-10 bleeding to 8 at redline
14" hg vacuum at idle (850 rpm)
18x8" SSR Rims


Test environment:

Elevation: Sea Level
Temp: 85
High Humidity
(Miami Florida)


I ran the test as per Gtech instructs, level road, correct vechicle weight. Using the "Hold" feature to shift at rev buzzer.

Shifts seem pretty tight, but I dont have any experience to go on.

I figured I would be at least 225 rwhp or so. Any ideas?

Is it the high temp and humidity robbing power or my automatic transmission

BTW my best 0-60 time was 5.8 sec. Powerbrake till 2500rpm

Thanks for the help!

 

I've heard from a lot of people that the Gtech's arent that accurate. Plus or minus 20rwhp.

You should be getting about 12-15 hp from the dp, 4 or 5 from the cat-back, and 1 or 2 hp from the pulleys

That adds up to around 245 rwhp

Best thing is to just take it to a dyno so you know what you're pushing

 

Oh yeah,

Forgot to add....my cats are gutted too.

 

I wouldn't trust those G-tech's as far as I could throw them. It's an accelerometer mounted on your dash... It makes too many assumptions.

Plus minus 20 hp sounds about right for the accuracy.

If you want to know your true RWHP numbers throw your baby on a dyno.