I have a 2006 GTO with the M6 and around 5,500 miles on the odometer. The following are 9 dyno runs that were all taken within an hour at Harris Speed Works. This was an open hood dyno with a fan blowing air towards the radiator. The weather conditions are on the linked dyno graphs.

Bone Stock:

Run #1: 348.4 Max HP, 371.7 ft-lbs, 11.8 a/f
Run #2: 351.0 Max HP, 374.9 ft-lbs, 11.9 a/f
Run #3: 349.6 Max HP, 365.9 ft-lbs, 11.8 a/f

After LS2 Portworks Ported Throttle Body Installation:

Run #4: 359.3 Max HP, 374.7 ft-lbs, 11.9 a/f
Run #5: 355.6 Max HP, 381.2 ft-lbs, 11.9 a/f
Run #6: 350.7 Max HP, 373.9 ft-lbs, 11.8 a/f

After LS2 Portworks Ported Throttle Body & AEM Cold Air Intake Installation:

Run #7: 364.9 Max HP, 390.1 ft-lbs, 11.9 a/f
Run #8: 359.9 Max HP, 385.3 ft-lbs, 11.8 a/f
Run #9: 359.9 Max HP, 380.6 ft-lbs, 11.8 a/f

Unfortunately, the ported throttle body threw a P2119 - Throttle Closed Position Performance code. After it was deleted with a scanner, it came back after a few miles of driving. After the battery was disconnected to reset the PCM, it came back after a few miles of driving. I had to go through the low performance mode nightmare as I couldn't drive more than 5 miles per hour! My friend and I soon figured out that it must be a bad throttle position sensor, but we couldn't even swap the sensor from the factory TB to the ported TB, because we needed some exotic tool just to open the steel casing around the sensor. Finally, we just replaced the ported TB with the factory TB. That worked. I returned the ported TB to LS2 Portworks and I'm now waiting for another one...

Next up is a ported intake manifold, Kooks longtubes with cats, a Spintech catback system, and a dyno tune. Can I get over 400 rwhp with just these basic bolt-ons? No doubt (and you LS2 GTO owners probably can too). Should I stop treating my car like a dyno queen *** and just take it to the track? No way, because I couldn't run a good quarter with a 6-speed to save my life. Nevertheless, I'm still happy with my daily-driven dyno queen. That's what matters to me.

 

ncie gains from the tb, but almost nothing from the cai..strange.

 

5 hp gain from a TB isnt bad.

 

a/f is a bit much. We had a dyno day and 4 goats 6.0's and 5.7's ..and all really had bad A/F's and timing from the factory. They still managed 340-353rwhp. Dial in that ECu with HP tuners or efi live and watch your numbers jump. So with a tune plus long tubes you should hit 400

 

he gained 10 ft of tq. i mean if its rated at 400ft tq flywheel and hes less than ten off that at the wheels with a ported tb and cai thats good. that means hell be putting like 410ft tq with headers.

 

5hp-15ft/lbs nothing?
Not bad for a CAI IMHO.

 

I've heard from my friend with an LS2 goat that CAIs almost hurt because they flow so well that it throws off something with the IAT? He then showed me this OTR CAI setup and a different IAT that's far more sensitive that looked kinda neat... awesome numbers btw.

-J

 

3 pulls is a small sample size, each mod obviously helped, but, you're taking the extremes that best fit your hypothesis. one run with the ported TB was actually WORSE than your best pull in bone stock form. runs 9 and 5 are similar, and runs 6 and 2 are similar. very confusing data.

 

Those are impressive stock #'s!! I guess I haven't been reading enough on the LS2 version GTO's!

 

Due to the infamous heat soak issue of the GTO LS2, any more runs would have caused the car to lose more horsepower and torque. As you can see that, for the most part, the GTO's best runs were the first of every three runs.

 

let get this one back to the top...

 

Great results

I plan on getting a ported intake and tb fromt hem myself.

Did you recieve a new tb yet and do you have any coders from it ?

thanks

 

That's a pretty torquey little ****...

 

Yup. In fact, I'll be installing the third ported throttle body from ls2portworks.com. The first ported throttle body threw the following code:

2119 - throttle position closed

The second ported throttle body threw two codes:

P1516 - Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance

P2101 - Control Module Throttle Actuator Position Performance

Only P1516 can be tuned out with HP Tuners. P2101 is the result of the porter removing the throttle blade and reinstalling it. The third ported throttle body did not have this modification done. Hopefully, this third one won't throw any codes. If it does, then I'll just send it back and get a refund. I'll also forget about a ported LS2 intake as well since those two parts go hand in hand. Cory Harris at ls2portworks is a great guy though. He's giving me a $100 refund for the problems that I've experienced with his throttle bodies. He's basically just going through a learning curve.

 

It's a different kind of dyno jet so the rwhp and ft-lbs numbers aren't so close (unlike with the standard dyno jets). I'll eventually get the car re-dynoed at a dyno jet that will show the accepted numbers. I think the horsepower will be about the same, but the torque number will be a lot closer to the horsepower number.

 

Thanks for the info. I am following your progress before I place my order

 

Good numbers. I doubt 400, but guess 375-385 might be possible.