HP numbers...Please advise

[bdiddle]

Greetings,

This is my first post on the forums, but I've been trolling for some time now. I have a 2007 GT500 and never really drive it, but got the urge to make it faster. That being said, I bought the JLT stage 2 kit from Evo Performance. Installed the pully, intake, and downloaded the program.

Long story short, I decided to go to a local Dyno shop to make sure the Air/Fuel ratio was working properly to ensure I don't grenade my motor like a buddy of mine did after installing the Kenne B system. Anyhow, in 3 runs the Air/Fuel ratios were fine, and I clocked in at 509.75 RWHP. I live right around sea level, the weather outside was rainy at 65 or so degrees. I'm in Northern California. Car has 300 miles on it.

My question is are these numbers low? Should I have it redone at a different shop? I've seen various others reporting different numbers, but wanted to ask here. What should I expect? And what are others pulling on the Dyno.

Any advise or number would be really appreciated.

Thank you,

Brian

 

[dbk]

Dynos vary from shop to shop but they do seem a smidge low. Was it a Mustang Dyno or a DynoJet? How much boost is the car making?

 

[bdiddle]

It was a DynoJet and the boost was reading a touch under 13.

 

[ROCMAN]

It's all in the tune. Mine is around 550RWHP with the same mods. Also, you need to break your motor in a little more. When you get over 1K miles on it, it will have more power. Which pulley do you have?

 

[DoctorV8]

It was a DynoJet and the boost was reading a touch under 13.

What correction factor was used, if any? SAE or STD?

High humidity (you mentioned rainy weather) can adversely affect your reading as well, combined with a green motor, probably account for the (temporarily) missing ponies.