ok guys thanks for the info it aint even hardley there once you get use to it ! Bike runs great with the 57's

 

No reversion, as previously stated: Never heard anything coming from my air filter. Currently using Cobra PowrFlo Air Intake, its possible I'm not experiencing what others are experiencing "reversion" as PowrFlo air filter housing is open in front & open towards engine and baffled by design on other side comparing to other open air systems.

In proving previous statement, I had my PowrFlo on stage I, w/4" Rinehart slip ons, gutted cat, and PowerPro Fi2000 CVT/AT fuel tuner, and heard no reversion during 10,000 miles and after stage II recently this year adding Andrews 57h cams adding an additional 5,000 miles. Sounds the same as stock except awesome choppy idle, and outstanding performance.

Buuuut also witnessed no popping either, a sound possibly indicating a lean condition (as some caned maps may produce). Not sure if lack of not witnessing reversion might be due to PowrFlo design or using amazing Fi2000 CVT/AT fuel tuner. Either way, this combination eliminated or prevented any reversion from occurring regardless of any modification.

B Bop

2012 FLHR (Road King) Ember Red Sunglo & Merlo (stage II)
Cruise Control, ABS, Chrome Aluminum Profile Laced Spoke Tubeless Wheels, Security Package, Saddle Bag LED Lid Spoilers, and an array of accessories that enhances nostalgic appearance & blood curdling performance.

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Air/fuel mixture isn't related to actual reversion. And thank you for your input! That's good to hear that you're not experiencing it. I wonder if other 57 owners will chime in?

 

I suspect that you are experiencing the same "reversion" that others experience; just can't hear it with the mostly enclose air filter. Most of the posters reporting the noise are running open air filters.

 

I had a after market 2into2exhaust installed and that reversion noise was really loud. Had the bike checked out and was told it’s normal. Switched exhaust to the pro pipe and noise was gone. Resently I installed a fatcat and the reversion noise is back but not as bad as when the 2into2 exhaust was on. Must have something to do with the back pressure the exhaust makes

 

ok cool i been thinkin on a pro pipe swap anyway after riding it awhile it aint very bad i geuss i got use to it

 

The OP stated he hears this at about 2500 rpm. A "hotter" cam, such as the 57, will have reversion at lower rpm's; because it designed to make power in a somewhat higher rpm range. An open A/C just let's you hear it more.

 

Run an auto-tune session on the PowerVision and get an idea of how much its trying to correct as to how close the map you're using actually is...

 

Never heard anything unusual like reversion from the a/c. Been running 57's with catless header and three different pipes with a hi flo a/c using the Rushmore cover. Even with fatshotz pipes that are whisper quiet, I never heard anything. All the pipes used do create back pressure - Fatshotz, Fullsac 2" baffles and Fullsac 1.75" baffles. Reversion is definitely affected by back pressure. Someone posted a very good vid recently explaining reversion. ie exhaust pulses, velocity, flowing backwards, and how back pressure effects it.

 

You didn't install yours straight up either, not sure if the OP did or if they are advanced.