All dyno's read a little different. Factory pro read way low, I forget why. There is a factory Pro in Houston. Several people have been tuned on the Factory Pro and then gone to Johnny Cheese, my tuner, and they all ran faster after JC tuned their bikes. Of course JC is the best. The Factory Pro checks four gasses and, when tuning, all four are adjusted, I think. Johnny says the Factory Pro Is BS.
"which is best" is a loaded question, both can be useful.
Over a 10 year period, I have had my bikes (drag & LSR) on:
1) JC's Round Rock, TX Dynojet (inertial & brake) dyno prob 20 sessions (many hundreds of pulls)
2) Andy's Houston, TX Factory Pro (load - eddy current) at least 52 sessions (many hundreds of pulls)
I kept detailed notes at every session, almost every pull.
Q: Which is best?
A: Dynojet, if you want a bigger number "hp" number.
A: Factory Pro, if you are developing a motor, testing component changes, need consistent data over a long period of time
Q: What about A/F & ign timing tuning for that big race coming up?
A: BOTH can be good IF:
- Dynojet: you MUST have an operator who is REALLY experienced, like JohnnyCheese
- Factory Pro: you MUST have your own A/F logging on yr bike (FP does not log A/F)
Basically: before "going to the dyno", 1) know your specific objective and 2) know your operator/equipment.
I "went to the dyno" before EVERY LSR event to assure the motor/drivetrain & all my subsystems were GTG.
I love JohnnyCheese like a brother, he is a great tuner, and i recommend him
But i gotta say that I really loved hearing my bikes on Andy's FactoryPro when he'd hold 11,000rpm
under full load for 15 seconds.
This was supposed to simulate a 1 mile LSR pass, plus the sound is like nothing on earth when standing 5 feet away.
Karl