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dyno question

Go to 50 different dyno's & you'll get 50 different numbers. The value of a dyno is comparison.. dyno it, tune it, then dyno again on the same dyno, same setup etc. Only the difference is a reliable number.
 
Go to 50 different dyno's & you'll get 50 different numbers. The value of a dyno is comparison.. dyno it, tune it, then dyno again on the same dyno, same setup etc. Only the difference is a reliable number.

I agree.

The dyno is a tool....but it must be used properly.

In order to get the most out of it, it's best to find a shop that you trust. An experienced tuner using a quality calibrated dyno can be helpful to optimize your combination and tune.

The key is using the same dyno and operator that you trust.

Most of us don't race on the track. For those that do race, the track is where the best tune can be done. The timeslip tells the tale.

I have a friend that has a Mustang he races. He designed and built the engine. He also spec'd the custom cam he had ground. The car has never been on a dyno. All his tuning gets done at the track. He runs 9.30's at 140+ mph.
 
Yes. If you want a real hp/tq number use the 1/4 time & weight of vehicle & some other stuff in a mathematical formula & you'll get that number.. sorry, don't know the formula off hand but you can look it up. You can only get the real numbers at the track.
 
jjdh-albums-exhaust+install-picture2704-stage_one.jpg

here is the dyno sheet, full stage 1

here is the dyno stock exhaust, heavy breather, on the portable.
jjdh-albums-exhaust+install-picture2701-portable_dyno_stock_exhaust.jpg


see the difference from the portable, to the hd dyno. the portable had stock exhaust
 
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Well.....if you notice one sheet is rpm and the other is mph. Also note the different scaling on the first sheet (hp/tq). That's why the lines don't merge at 5252rpm like you would see normally. The correction factors don't look out of wack, but there's no a/f reading on the bottom sheet.

Do you know what gear each dyno test was done in?

Model # of the dyno used? DynoJet has both inertia & eddy brake capability depending on model.

Can't really tell you which one to trust. All in all I'd probably stick with the dealer rather than the portable tho.
 
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