I had my car dynoed by a local shop and this was what my pull was:


Then I knew something was wrong. So today I had Justin at VMP dyno my car...exact same mods, and this was the result.



I feel a little better now.
*** Tech question...How is this possible that one dyno can be so far off? I mean the weather was almost exactly the same, with the same mods, with almost 40 more hp on VMP's sheet?

 

was your second run with a 93 tune and 4.10s?

 

I don't trust dynos. The local dynojet had mine at 364whp while the mustang dyno had it at 337whp. Almost 30whp diff.

I'd suggest a mustang dyno if you can locate one. 40whp though! that's a LOT.

 

Yes the 4.10's were different, but that shouldnt reflect on my horsepower.

 

One dyno to the next can be different and drastically...just depends on the tuner and the calibration and could be as simple as that

 

Good numbers! I just had my car dynoed, and the place where I got it dynoed said that the position of the tire on the roller could cause some incorrect readings. He said that if the car is sitting directly on top of the roller, the wheel could be slipping a little thus giving a lower reading. That may be part of the problem with your first pull. Then again 40 hp is a lot just for possible incorrect tire placement.