Guys that is what shootout mode is for on dyno dynamics. All variables are fixed when in shootout mode so various shops/operators see the same numbers I'm not sure if mustang dyno's or dynojets have such a mode.

 

shootout mode on a DD is just a certification that shop owners can do to have their DD factory approved to where the numbers are directly comparable to other DD's with the same certification.

[QUOTE]The ShootOut mode system is not just a hardware or software upgrade

 

I'd rather read off of the strapped down car on rollers than a dynopack trying to account for a wheel THAT's NOT THERE! lol there's a ton more variables that the dynapack is trying to account for than a dynojet.

so far the dynojet is the only one that doesn't have a user defined variable that can throw off everything. the only thing you could mess with is the weather station but it would be pretty obvious if you were dynoing your car and the shop guy was putting a heat gun on the weather station and worst case you post an uncorrected dyno and it ignores all the weather anyway.

 

Trying to compare dynos is a worthless debate. Even amongst the same dynos (i.e., dynapack to dynapack) they do not read the same. There are WAY too many variables. Heck, even the same dyno will produce different results...even on the same day.

FWIW...when I had a N/A S2000 I made 246rwhp on Church's dynapack. The exact same setup, same testing conditions, etc. made 225 on AutoWave's Dyno Dynamics Dynamometer.

I am not going to debate the differences...but will simply tell you the that best thing you can do is baseline on a particular dyno and continue to use that dyno as you modify your car. Although the results will not be perfect, you will have the most accurate measurements period.

 

this is pretty interesting, i wanna go to a dynojet now to see what i put down

 

you're right, all dyno's will vary a little, but I've seen camuman's car on two different dynojets on different days and the corrected difference was only 1.6%. considering the weather was 23 degrees different from one day to the other the intercooler was probably just working better on the one run and that was probably a bigger cause of the difference than the dyno itself.

my old CRX was within 1.1% on the same dynojet with 6 months in between the runs.

 

that would be cool, my guess is that the results would be in between the dyno dynamics and the mustang.

 

I'd rather read off of the strapped down car on rollers than a dynopack trying to account for a wheel THAT's NOT THERE! lol there's a ton more variables that the dynapack is trying to account for than a dynojet.

so far the dynojet is the only one that doesn't have a user defined variable that can throw off everything. the only thing you could mess with is the weather station but it would be pretty obvious if you were dynoing your car and the shop guy was putting a heat gun on the weather station and worst case you post an uncorrected dyno and it ignores all the weather anyway. [/QUOTE]
I hear what you are saying, but the dynapack doesn't try to "account" for the wheel, it just reads what it reads at the hubs, ignoring the effects of interia and outside variables lilke the ones mentioned in my above quotation. If the tuner wants to set some sort of correction, then he can, but the factors I mentioned are somewhat out of the tuners hand on a roller dyno.

I could see how one can make the arguement that a roller dyno simulates the real world better with tires and all, but for consistent readings and for sole tuning purposes, I think it's hard to beat a chassis dyno..

 

I think that's why the software used to say "flywheel" on the dyno graph

 

That still doesn't translate into flywheel horsepower as there is still drivetrain loss. I think there was a "title" error when the software was initially developed and nobody has bothered to fix it. I think the power should be referred to as hub horsepower even though a TCF is used which is supposed to account for wheels.