my engine runs wonderful on countryroads and in town but on a dragstrip it starts sputtering all day long.
Today sucked! I changed sparkplugs, reduced boost, used BAD V-R's Temperature override switch, put in different fuel - nothing helped.
When the boost kicked in it started sputtering / misfiring but AFR was ok.
On the way back home all was ok again.
Maybe the ECM gets confused by the burnout / hitting the rev limiter?
I put in used Iridiums with normal gap.
Everything was normal again on the way home from the dragstrip, including several miles Autobahn, hard launches from a traffic light wide open throttle through all gears.
I have contacted Messrs Daytona Twintec regarding VRFI...
My guess would be that on the strip when the traciton is there it makes more load on the motor.
On the street there is less traction (more wheelspin) and hence less load on the engine.
I have had that problem before on turbo cars and you have already addressed the obvious issues (reduced boost, increased fuel pressure/octane etc.) so that is where I would look next and hopefully it helps.
Thank you all for your advises, your feedback is highly appreciated.
Meanwhile I have ordered a VRFI ECM, always wanted to have one because of other issues with the stock ECM.
For sure I will follow up spark plug gapping.
i would place a bet its down to fuel flow ,have you still got the original v-rod fuel filter in the tank ? i had exactly the same problem and fitted a sytec bullet filter in its place in the tank bike feels a lot stronger since i did this but its the season end here so will get a power run on the local dyno as i put v/h street cams in as well