I am at my friend's shop in Harrisonburg and my car is still on the dyno.

3/7/2005
Mustang Dyno @ Performance Motorsports
256.3 hp @6250
232.8 tq @4750

7/31/2006
Dynojet @ DryftMotorsports
241 and 240 hp

I was like WTF mate? Dynojet numbers are supposed to be higher right?? So we unhooked the CAI wondering if the filter was uber dirty...231 and 233 hp.

I dunno...I dunno.

Mods:
Nismo V1 Cold Air Intake
Kinetix V4 Intake Plenum
Crawford High Flow Catalytic Converters
Borla Dual Exhaust
Altered Atmosphere ECU REflash

 

Apparently this is possible.

Besides the obvious, like the different times of year (temp and humidity) that your runs were made, other factors come into play. SAE correction for each run, how well the car was strapped down, cooling between runs, calibrations of the dynos, etc. I know most guys say a Dynapack runs higher than the "gold standard" DynoJet, but I know of one in my area that runs within a hp or two of AAM's dynojet, and on the low side at that. It all depends on how it is setup by the operator. Comparing between machines is useless.

 

A correction factor to DynoJet numbers was put into in the Mustang dyno and the correction was to high . With out it a Mustang dyno would have been in the low 200's

 

+1 The shop that has the Mustang dyno inflates #'s and obviously didnt tell you

 

We had a car dynoed at PM WAAAAAAY back in the days when they still talked to us, it made 389 or so, then we went to a local Dyno jet the next day and made only 350 or so.Thier numbers are trumped a bit.