Conversion Factor from Mustang to DynoJet?
 

I spoke with the Mustang Dynamometer operator/tuner, and he said the conversion is 12% (he says it may be more like 15%) between the Mustang and the DynoJet. All of my past runs have been on the DynoJet. If indeed it is 12% (or 15%) additional then I am happy with the runs. If the Mustang and the DynoJet are roughly equal (which I don't think so), then I am back to where I was roughly 4 years ago.

As a side note, the tuner was only able to pick up just less than 30RWHP when playing with my tune. He was really pleased at the tune that was already in the car. He and his crew spent nearly 2.5 hrs hacking trying to find more HP, but said that the only way to get there is to move to xxOH injection. I was actually down by 4-5 psi from the previous MRII combo. We even went so far as to make a pass without air filter installed (~5RWHP difference).

So.... if anyone knows the conversion factor, you might provide some relief or just lead me to frustration.

Jeb, TJ, BTF, chime on in. :)

Aaron

I read an article from an owner of both machines that the Mustang Dyno read 11 or 12% lower than the Dynojet. Years ago, I ran my GS on a Mustang dyno which yielded 284 RWHP. I recently ran it again on a Dynojet and it only mustered 299 RWHP. This is not near the 11-12% difference. There were several changes made to it after the Mustang run and before the Dynojet run (Hypertech tuning installed, gears changed to 4.10's, and removed the Breathless cold air and replaced with an SLP). So my application is not really a good example.

This shop has both a DynoJet and a Mustang Dyno, but only the Mustang is set up with the wbO2. Even though my car has the wbO2, they like to verify the on-board wb when doing any tuning. Plus they can charge more with the wb.

It sounds like the operator was correct on the 12% difference.

Aaron

A freind of mine works for a diesel performance shop in Utah. They have a Mustang dyno in 1 bay, and a Dynojet 240C in the other. He dyno'd his 01 Camaro SS on the dynojet and made the typical 310 RWHP. Right after that he strapped it to the Mustang dyno, and made 245 RWHP. 65 HP difference.

For what it's worth, I don't think the difference is percentage based. If I make 1000 HP on a Dyno Jet, I should make 880 on a Mustang dyno if the difference is 12%. I think the 65 HP difference that my buddy experienced is pretty much the difference regardless of how much HP the car has. 1000 HP on a dynojet would equal about 935 on a Mustang dyno if I am right.

Im inclined to agree with the 12-15% range, however it is soooo easy to mess with the variables and get very different #'s. My dyno (dynomite) seems to be on par with the mustangs.
For example NOPI was this past weekend. A friend of one of my customers had hos car dyno's there on a dyno jet. It made 278whp.corrected. The very next day we strapped it to mine for some tuning and it made 212whp corrected. Quite a substatial difference.
My buddy's z06 made 430rwhp on a dynojet-369 on my dyno.
Id be more concerened about what it made from the begining to the end of the day.

I think the question has been answered. The difference between the Mustang Dynamometer and the DynoJet is ~12%, with the DynoJet reading higher.

As an aside, the dyno operator said that he can adjust the MD to read the same as the DynoJet, but then when you run in the 1/4, the trap speed will not match up with the HP that is indicated by the dyno. He feels strongly that the MD is a more accurate indicator of "real HP".

Thanks for all of the input.
Aaron