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The values posted for Horsepower, Torque, and MPG are attainable with a good tune. They are conservative and do not reflect the maximum values we may see with our complete kits, a GREAT tune with no detonation, as well as proper exhaust and carb/TB selection. If you are not getting the numbers as stated or higher, there could be an issue with the exhaust provided, tune, the assembly, or break-in.

We state a range for reasons I will outline below. None of these points are intended to be comparative or derogatory and come from our expericences as well as feedback from qualified dyno tuners across the US, Canada, and Europe that we deal with regularly:

Variances in dyno brands, models, and software versions which can account for as much as 10%

*Superflos and other brands can average 10% lower than Dynojets
*Newer Dynojets or those with recent software updates on average report lower numbers than older units
*Proper dyno maintenance

New developments in the Harley product line

Industry wide, many tuners report that late models produce 5-7% lower numbers on average than previous models with the exact same build specifications. Logical theories have suggested:
*Parasitic loss in the transmission due to gearing changes and helical cut gears
*Parasitic loss due to the ratchet style primary chain tensioner locking too much pressure onto the primary chain
*Throttle by wire and the throttle plates tendancy to not open to 100% throttle until 3000rpm on average

Tuning method and data reported

*Gear selection for the pull
*Correction and smoothing factor
*Air/fuel and Ignition timing chosen
*Tuning device (PC, SERT, DTT, etc)
*Ventilation system in dyno room


*Proper tire pressure
*Correct throttle cable adjustment
*Clutch slippage
*Tire traction on drum

Atmospheric Conditions

Dyno correction factors are designed to compensate for these issues, however results can still be affected by altitude, temperature, humidity and barometric pressure

Good Tune Check List

*40-45mpg with reasonable riding
*No detonation/pinging
*No fuel smell to the oil
*Clean spark plugs
*Great drivability

We go through great lengths to ensure the quality of every product we produce. We are not a factory and don't have a huge assembly line or labor force putting parts together. Everything is re-engineered by the same human hands, every time, to exact standards to ensure consistancy...just the way it's been for over 10 years. We have control over this...but not the other factors above.

A dyno is a tool not a defacto standard. There is no such thing. Look at the performance before and after the build...just make sure everything above is EXACTLY the same.