Originally Posted by drewTT

heres my graph. expected a little more power up top. my torque was wayyy higher, which is a little odd

Originally Posted by Harman Motive

I agree that the numbers produced by this dyno are conservative. It is well known through the tuning community that Mustang dynamometers will read on conservative side - I knew this when we purchased the dyno.

My experience with dynos is a little more complete than most. I have now owned two dynos (Dynojet and Mustang), dynoed well over 1,500 cars over the last 4 years, and spent most of those runs performing custom tunes. I have also tuned vehicles on Dynapack, Dyno Dynamics, DTS, Maha, and Bosch dynamometers. So while the information below may simply be my opinion, I've got the time invested to back it up.

Cliff Notes:

1) Mustang Dynamometers generally read on the low side of the spectrum.

2) We had a Mustang technician fly out here to calibrate our dyno on site after we installed it. I check/recalibrate the dyno monthly during our routine maintenance.

3) I owned and operated a Dynojet for 3 years before we installed the Mustang, and trust me, I changed dynos for a reason (it ain't cheap).

4) The Mustang dyno combined with our enclosed dyno-test cell provides the truest simulation of real world conditions. As such, regardless of how "high" the numbers are, they are more comparable/repeatable and as such are more useful than numbers provided by some other dynos and test cell setups.

5) The accuracy of a dyno and its calibration is about consistancy, repeatability, and correct simulation of real world conditions - not how high the numbers are.

6) I am not knocking those who want to see higher numbers. As with all things in life, you need to make compromises. In upgrading from our Dynojet to the Mustang we decided repeatability, consistancy, and tuning quality were more important than higher numbers.

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I purchased the Mustang dyno last year when we decided to move into a larger facility. I decided it was time to upgrade from the Dynojet 424X we had in our old shop for the last three years. Furthermore, I decided it was time to invest in a proper test cell to improve repeatability and testing accuracy. This was an extreme investment in money, time, and engineering - but I got into this business to do the best work possible, not just to get by.

It was well known to me that the Mustang would read lower than the Dynojet. I accepted this knowing that the improvements gained from having a proper load-bearing dyno would far outweigh the marketing power of higher numbers.

What I like best about the Mustang is the integrated eddy-current load cell and the software that controls it. The load cell applies resistance (load) to the vehicle as it accelerates. By entering the vehicles weight and aerodynamics (hp @ 50mph), the Mustang calculates the amount of resistance the vehicle would encounter on the road at a given speed. As such, load is increasing as the vehicle speed increases.

An excellent example of the accuracy of this loading was done during the dyno day. We ran a few of the cars in 3rd and 4th gear - the numbers/graphs produced were almost identicle in each gear. The would not be so on the Dynojet or an insufficiently ventilated test room.

The Dynojet we had before was an inertia dyno. The load was simlpy from the weight of the rollers themselves (~2500lbs each). As such, running vehicles in different gears produced different results. Furthermore, the resistance did not increase as speed increased - unless you are driving your car on glass in a vacuum, that just doesn't equal the real world.

The real benefit of all this really shows when tuning vehicles and when analysing the quality of the tune. With the applied load on the Mustang, you are less likely to get away with a tune that is too agressive or poorly matched to the vehicle. This can be seen in power dips, lumpy curves, etc. On a Dynojet or similar, the lower loads at high speeds usually will let you get off a couple of runs before you see any of this behavior (I found that I had to check/retune some of the cars we ran on the Dynojet).

So, while the numbers may be low, the data it is presenting to the reader has more value. The Mustang dyno combined with proper ventilation and calibration allows you to see how your car is running on the road - not just how your car runs on the dyno.

It can be argued that all this is rather unneccesary if you are just trying to get a power number out of a car, but why go through the trouble of printing a graph if you just want a number

If you guys have any other questions just let me know.

Best Regards,

Dan

Originally Posted by SCM3

Yes, the numbers do seem pretty damn low. Although Drew's seems to be on par with his previous dyno's, unless his car is a true freak now and makes 500rwhp on a dynojet lol.

Originally Posted by drewTT

heres my graph. expected a little more power up top. my torque was wayyy higher, which is a little odd

Originally Posted by Bodybag

What blows my mind about his Drew's curve is how early the power sees it's max, and then just holds it. Drew's car and mine have very similar components with the exception of different brands of exhaust and different software. We made similar HP numbers too, but mine builds all the way to redline, and his is all-in by around 4750rpm. Could be his race-file and 100 fuel, but I'd guess that his exhaust is outperforming mine and that's where most of the difference is.

It would be interesting to flash my GT2 with a GIAC file and run it again. That would basically make both of our cars equal in setup with the only difference being exhaust, then it would be easy to determine if the exhaust or the flash was responsible for the difference in power.

Originally Posted by drewTT

yeah its a little weird how it flattens out the power.

can you post your graph?