'07 FLHX, S/E performance one piece slip on mufflers, stage 1 ecm download, s/e a/c. Last week I put on a set of s/e one piece performance slip on mufflers (street legal). Today for an experiment I removed the s/e a/c andput the stock air box w/stock air cleaner element back on. The mufflers sound deeper and for some reason the bike seems more responsive and overall feels more smoother. Possibly by having the stage 1 ecm download and using stock air cleaner box the bike feels more responsive because the motor is getting more fuel? I know the bikes run super lean from the factory. I remember reading an article by Joe Minton in American Rider where he says that the stock air box makes more power in the usable rpm range than the s/e a/c.

 

I remember reading that article as well. He stated something to the effect that the MOCO had spent alot of time engineering the system. If I remember right tho, Joe had not yet added a tuner (PC, SERT, DFO, etc.)

 

The Stage 1 download from the dealer is pretty much useless.............it's a waste of $150 to make people feel safe.

Put on a real fuel management system along with the free flow air cleaner and free flow exhaust if you want real results.

Steve

 

Probably more tq with the stock intakewith factory flash. More tq=more responsive.

 

The "stage one" reflash is not useless in and of itself. It certainly modifies the VE tables, which are the basis for the fueling calculations. With the stock airbox now back on the engine, it will no doubt be calculating too much fuel, then removing it again while in closed loop operation, so unless the flash changed the AFRs (not likely, since it's EPA-correct!) then the result will essentially be the same as it was without the flash. In closed-loop operation, at any rate. Maybe in open-loop too.

At least with the stock flash the adaptive fuel routine would be adding fuel in open-loop with slip-on mufflers. With the stage one flash it'll be subtracting fuel there (but subtracted from more calculated fuel). In the end, getting the stage one flash and not using the stage one intake would mostly be a waste of money.

I saw that article too and couldn't freakin' believe they'd stick that stuff on an engine without making arrangements to get the fuel right. I especially couldn't believe they'd stick it on a dyno. It doesn't surprise me it'd run better with the stock air cleaner. I know mine runs much better with the K&N airbox in conjunction with the PC-III controller.