Modded 02 GTP Any way to estimate horsepower/torque?

**EB0286** · 03-19-2014

Hello, long time lurker here finally decided to signup, glad to be here in what seems to be a pretty friendly community here. Being a long time Pontiac fan and driver I bought a good condition 2002 GTP Fully loaded. I had since done several modifications however, no easy access to a dyno make me wonder what kind of power I'm putting out with my current mods. I understand that there are many many variables involved which makes it difficult to estimate power without actually dynoing the car but I was hoping some of you guys might be able to give me a rough estimate of how much horsepower and torque I might be making at the crank.

Wizaired Cold Air Intake
ZZP 3 inch downpipe with High Flow Cat
ZZP PCM tune
3.4 Inch Pulley
90,000 miles on car, well maintained, always had synthetic oil

I'm certain I have some knock since I'm running the stock ac delco plugs and thermostat, but I have some more supporting mods on the way like a 180 thermostat and some autolite 104's. I'm curious how much power that might add as well.

**Elite6** · 03-19-2014

Depending on the knock, probably 240HP to 270HP at the crank

**hensleya1** · 03-19-2014

Get a scanner for knock.

Driving a modded car without scanning is like banging a hooker without protection and HOPING you don't catch something.

***

Depending on the car, you may see knock... you may not. I was seeing upwards of 6* with a 3.5 pulley. I had to get rockers to put an end to that. Some can run a 3.4* on just a downpipe with no problems.

As to HP, I would guess around 270-275 at the crank... if you have no knock. So 220, maybe 230 at the wheels. Each degree of KR takes away about 5 HP.

**stealthee** · 03-19-2014

Where are you at in PA? I'm in southwest PA and there are dynos all over the state. Hell there are two, an AWD and a 2WD dynos within 20 miles of me.

**EB0286** · 03-19-2014

Thanks for the reply's guys. That is what I was thinking, around 270 to 275. Getting it scanned for knock is definitely on my to do list. Will the new plugs and thermostat help to reduce some knock? Without knowing what level of knock I have now, is there anyway of knowing what I would be putting to the crank after the new 104's and thermostat?

**EB0286** · 03-19-2014

Originally Posted by stealthee

Where are you at in PA? I'm in southwest PA and there are dynos all over the state. Hell there are two, an AWD and a 2WD dynos within 20 miles of me.

To be honest I didn't really make a real hard effort to locate one. I just recently started modding the car, and don't want to pay for a dyno when I have plans of adding more bolt on's and supporting mods over the next several weeks. Once I get to a level where I have the few bits I want done, I will find one and have it run. I figured it would make due to come here and get some estimates.

**dsmuts** · 03-19-2014

I'd say you're around 220ish hp

**Fivefingerdeathpunch** · 03-19-2014

Well if we already make what GM said was 240 hp and 280tq at the crank, with those mods just add 20.

Wheel horse power will be around 220-230 after drivetrain loss.