Re: Percentage diff between a Chassis Dyno and an Engine Dyn
 

As with any dyno, the numbers don't actually matter, it's the DIFFERENCE you see from the changes that matter. The shops I was refering to had Super Flow engine dynos and Dyno Jet chassis dynos. Mustang dynos don't alwaye read lower. Depends on the operator and the load factors they use. When the ATI Procharger people hauled their prototype cars from my shop (Dynojet), after tuning, to their place (Mustang dyno) they typically picked up around 5%.

Re: Percentage diff between a Chassis Dyno and an Engine Dyn
 

Only thing I can tell you is my car lost 28% on chassis dyno.It was automatic then. Dynoed engine on superflow SF900AT It was calibrated as close as possible,air corrected to 29.9 baro 60 degrees. Then later we got a Dyno jet chassis so my car used to test it lost
28%.
As Ed said don't compare your # to others,just look at gains from where you started.
I don't know about others but dyno jet has setting where you let car coast after pull and it calculates driveline drag or % of loss I can't remember term they use.
I don't have much chassis dyno experience but in my opinion they probaly not as repeatable as good engine dyno.
Mike Taylor 3601

Re: Percentage diff between a Chassis Dyno and an Engine Dyn
 

Mike your sure right. A race converter causes more loss, also converter & fluid temp changes effect slippage losses. Tire slippage is another variable. Had a 10.5 car bring his car two days after it was on Reher & Morrison's engine dyno. His showed a 28% loss also. Mine has never been on an engine dyno. Sure hope mine looses more than 28%! LMAO!

Re: Percentage diff between a Chassis Dyno and an Engine Dyn
 

Ed,
Good morning.
Are you saying the HP math on your car is: 0 - 28% = 0 ??? :~)

Re: Percentage diff between a Chassis Dyno and an Engine Dyn
 

Pretty darn close. :-(

Re: Percentage diff between a Chassis Dyno and an Engine Dyn
 

Ed
Took a minute for that to register,your're saying you hope your driveline is worse than 28% so your engine is making more than what chassis dyno is telling you.I'm from Ky. takes me a minute or two sometimes.
I hope to have mine back on chassis dyno soon to test X pipe different mufflers,I'm interested to see how much less stick uses.
Mike Taylor 3601

Re: Percentage diff between a Chassis Dyno and an Engine Dyn
 

Mike, that's what I meant. Maybe my Okie accent makes me hard to understand. LOL