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Ignition/Tuner/ECM/Fuel InjectionNeed advice on ignition issues? Questions about a tuner? Have questions about a EFI calibration or Fuel Injection? Tips on Engine Diagnostics, how to get codes, and what they mean. Find your answers here.
I'm just starting to use the SERPT to tune my bike after a cam upgrade and I have a question about the values reported in the working VE tables. After a brief ride to record data and allowing the "Smart Tune" function to recommend changes, I have what I perceive to be a large difference between the front and rear cylinders. Is this normal? I expected the values to be much closer because theoretically, the Volumetric Displacement of both heads are the same. Should I be concerned? Please see data attached.
Thanks,
Mike
2008 FLHRC, Andrews 48H cam, Stage 1 Intake, V&N Propipe.
Not an expert, but the numbers reflect changes that the system has made. The object is to get the changes down to 5% or less, run to run. As for the balance between the cylinders, the exhaust system can play a large role. I wouldn't worry about it right now, concentrate on hitting the as many cells as you can for each data collection, then note the % of change. As you go thru different rpm ranges, different loads on the engine you will see the ve changes. It just takes time and effort and a little understanding on how things work. Patience is a virtue, lol!
Thanks Wmitz,
So I keep reading that the goal is to get the VE values to within 5%. Here's another newbie question, does this mean that the "Smart Tune" table values are to be within 5% of the "Working" table values?
Different readings between front and rear cylinders are normal. This take into account the different temps between the 2 as the rear runs hotter than the front. Timing and VEs are adjusted for each cylinder to compensate for the difference in temps.
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