thought I understood things by now but not well enough. Wouldn't you think that by replacing the stock restricted mufflers with free flowing straight thru core ones (opening the flood gates so to speak) making the engine not work as hard, that in turn it would allow the intake to suck more air in being the engine is for all intents and purposes an air pump? sure you're reducing back pressure and perhaps sacrificing some low end tq as a result, but part of me is thinking that thru the combustion process an ancillary benefit is improved air intake...the other possibility is that I have absolutely no effing idea WTH I'm talking about..LOL

being in the discovery phase of sticking with the OEM intake but doing the mufflers and Stage 1 calibration, which I haven't tried before, wondering if that is also improving the intake airflow..like I have mentioned in before my bike runs fantastic this way

 

There are multiple things that affect air flow. There are two that can be improved without opening up the engine: air cleaner and exhaust. One that can be improved by opening up the engine: camshaft. Then there are the more involved ones like valve sizes and throttle body intake diameter, but you're obviously not interested in the fancy stuff at this point.

Yes, if you "open up" your exhaust system you will indeed increase air flow. If you just replace the mufflers on your '17, you will still have catalytic converters in the head pipes, so the increase will be small. But it will be there.

 

The only way an exhaust system suck more air in from the intake is if there is overlap on the cam..

 

cool, thanks...kinda' figured the exhaust upgrade would maximize the OEM intake performance as well, and left me with the impression this configuration is not short changing the engine of what it needs for the Stage 1 calibration, and may run a tad richer in Open Loop, but was looking for some knowledgeable validation..I've done Stage 1, 2 and 3 on my previous Harleys but am 'throttling back' on this bike because it performs so well and don't feel the need or want to spend beaucoup bucks...

 

The problem with Harleys Screaming Eagle Stage one is they will not put enough fuel to the tune and there is no advance put into the timing. So it's like a air pump that does not make any pressure and only bumps the cfm a tad.... It really is kind of lame. Big Harley money for nothing. The head is going to flow well and improve combustion. But as I see it there is no way to feed it right and keep your warranty.

 

yeah, I think for such minor modifications as I have made it's about as good as it needs to be..I was just curious if I achieved say ~90% of the benefits of a Stage 1 by opting not to upgrade the intake, but it sounds like I'm closer to 100% than I am to 90. I really prefer the overall protection of the OEM enclosed air cleaner and noise reduction for as much touring as I do.

this started out with me just wanting the Street Canons, then discovering they require an ECM recalibration, so bought the tuner, had our dealership install, pick it and was told there is no calibration available for just the Canons so they did the Stage 1 calibration..bike runs fantastic, but in the back of my mind I wondered if I now have come up short and if there are any downsides to not upgrading the intake for optimization. It then occurred to me that perhaps the improved exhaust flow subsequently may have improved the intake flow as well, if not it may run slightly richer in Open Loop than it's intended to because the S1 calibration is set up for a specified amount of air which it may not be getting now..just want to know it's right and my shade tree mechanic thinking isn't off base

 

I would change the a/c to go along with muffler change,there are 3different SE a/c you can use. They will flow more than you have now.

 

thanks, but well aware of the offerings as have used them all in the past except now we're stuck with K&N only which I dislike, and none of them provide the protection of the OEM, and yes aware they flow more but that's not my point...which is trying to determine if the OEM flows all it needs for the mods I've done..and if the free flowing mufflers improve the intake flow...which is sounding like yes it does, but very minimally...so perhaps a fair statement would be that the difference in air flow between a stock intake and hi flow would be the diff between a clean stock filter and a high flow approaching cleaning time...all conjecture of course

 

If you take the oem filter off and run the bike on the dyno you get more power. If you add a free flowing intake, you get more power then the bike with the oem filter. If you remove the filter from the high flow intake, you gain, less power the you did when removing the oem filter and running the bike with an open intake. Without flow benching all variations of intake and filter, I can't give specific numbers as to how much more it flows, but it is apparent on the dyno. Mapping fuel in any of the combinations increases power.

After reading this, it may be confusing. The gain from removing the aftermarket filter is less due to the fact that it was already making more power then stock. Obviously the baseplate of the intake you chose can alter performance too, regardless of filter. You know that your filter is as free flowing as possible when your power gains from removing filter are miniscule

 

I recently purchased a set of SE Slip-ons for my 2017 Ultra Limited. Before I installed them, I talked with my H-D Service Advisor on his opinion about the ECM upgrade while using the stock air cleaner. His answer was although they are in business to sell upgrades (because I mentioned one of the questions asked on H-D website was do you need to reprogram after installing SE Slip-ons and a MC rep said yes), I should just install the SE Slip-ons and see how they perform. If all is well such as not having backfires on downshifts when exiting off ramps, don't worry about it. That's what I did and it runs fine.