Just a thought and a question I guess... For fairly minor changes to inlet or exhaust, doesn't the EFI system compensate and adjust fuel scheduling?

 

The answer would be Yes & No....

The OEM map is part closed loop (ECM adjusts the tune based on O2 sensor feedback) and Open Loop (no O2 sensor feedback, tune is based on algorithms for OEM equipment)...

The ECM in closed loop will adjust, within a certain percentage, for real time changes measured by the O2 sensors... This portion of the map is in the low load or cruising areas of the map, where many riders spend the majority of their time

The ECM in open loop, will not have O2 sensor feedback or make adjustments based on that feedback.... That will lead to a lean condition. Unfortunately the open loop portions are high rpm and/or high load portions where the AFR can be most critical... but that is the portion of the map frequented by spirited driving, or flat out racing style driving, where most people spend a small amount of time.

On a casually ridden motorcycle, with a basic Stage I, the the closed loop changes by the ECM could probably make the changes needed, and the time spent in open loop would be minimal, so no harm would come to the engine.

If you ride-it-like-you-stole-it, you could get dangerously lean in the open loop portions, and that could lead to engine damage...

So it's both Yes and No...

I always change my tune when changing the airflow through my engines... I have even flashed OEM bikes with an "improved OEM" tune that has made them run noticeably better...

 

My deluxe has V&H BSS, Screaming Eagle intake, and SE Race tuner ( stage 1). I change between the regular baffle and the quiet baffle quite often without any issues. However, the quiet baffle has no fiberglass wrapping. That's been long gone.

 

I had no idea Power Visions cost that much. I bought mine when it was first introduced. Dynojet had a tech working in Nevada that was sharp at setting up can tunes. Have a set of big shots staggard with standard baffles. Baffles are pretty much gone after 98,000 miles. Keeping them for the rebuild.