Going to the dyno, comparing dyno results

[SappySE107]

Im not an expert on dynos, but I have a lot more experience now and wanted to share a few things. One of the first things I remember hearing was that a mustang dyno reads lower than a dynojet. This is real, and its about 10%. The next time we dyno on the local Mustang dyno with the same vehicle done at R&R, I will add it to this thread, probably this post.

The attached 2 sheets are of the same pull but show different peak results. Its a 2000 Corvette 5.7, so its just for an example. Smoothing 5 is what we (WOT-Tech and R&R Motorsports) use for tuning. It smooths out the spikes to give you a more consistent result. The spikes are a result of the tire to roller contact. Harmonics/vibration in the drivetrain will cause the spikes to be in certain RPM areas, higher RPM especially.

Setting the smoothing to 0 shows all those spikes, and you will see the hp numbers go up when you do this. Its all legit, but its also just another factor to consider when comparing dyno results. Dynojet with smoothing 0 vs Mustang with smooth 5 would be more difference than you might have expected, which is just a part of what makes comparing difficult.

[SappySE107]

It probably wouldn't hurt to have a list of things to check before you go to a dyno. Tires are balanced, proper air pressure, New or recently changed oil and filter, air filter clean, O2 sensor working properly....all sensors for that matter. Any issues you are aware of, even those that you expect are a tuning issue. Injector spray pattern can make a difference, which is why I have a setup to clean and test injectors.