well for the first time Harley says ECM recalibration required for SE Slip-ons..they are much larger and freer flowing than the stock mufflers..when you look thru the stock ones they have some sort of flap/baffle/blockage that you can't see thru, the Street canons are straight thru core..so I choose to believe the folks that designed, built and tested the bikes that the stock calibration with the freer flowing mufflers needs a tuning alteration.what's another $300 to do it right anyway after spending over $20,000..people spend 10 times that on chrome and crap without balking at the expense..my bike runs great and I know it's not overly lean which gives me peace of mind.....to each his own of course

 

Over on HTT, Darren, tuned a box stock 2017 with PV then added the slipons and re-tuned.. All he got was noise. Both outputs were identical.. He added an Se air cleaner re-tuned and got 5hp/3tq. Gained power / TQ everywhere..

Look for Durwood in the M8 section..

 

I did the Heavy Breather, street cannons with the HD tune. I read the same comments about no tune needed. I am no expert on anything so I read and listen to people who know what they are doing. The advice I listened to was this:
It is true, you do not need a tune with new breather and Cannons. However without the tune the ECM will be running at the wrong baseline as you now have more air going into the motor. The ECM can and will try to compensate but it will not have enough bandwidth to make the required adjustments as you ride. With the tune the baseline is changed (AFR mostly, I think) such that the ECM can make all required adjustments to the motor as you ride. Kind of shifts the baseline of the motor with the higher airflow. I just spent $30K on new bike, another $300 to get the proper tune seemed like a no brainier. By the way my dealer tried hard to get me to use the TTS tuner, but it was not in stock yet and I did not want to wait, so went HD. Last note, my dealer has purchased and tried multiple tuners including the FP3, they prefer TTS, and the general manager guaranteed no warranty concerns with this tuner (but I am sure this is dealer by dealer).

 

no surprise on muffs not increasing numbers....Harley publishes their SE Stage 1 increase to be 5 tq at 3500 rpm's and ~2-3 hp across the range..if Harley reintroduces their synthetic media S1 AC for the M8 I'll consider adding it but not using a K&N, and I just flat out much prefer the filtration, protection and noise reduction the OEM intake provides for the touring miles I rack up at the expense of a small performance gain..but folks have different requirements..I ride solo because my wife has her own...if not and I had to ride two up all the time I'd go straight to the S2 tq cam probably

 

I like what riknbeth has to say. We all spend over $30k on new M8 touring bikes and than want to customize them a bit with exhaust and breathers, and than we don't want to tune them for $300.00 bucks or so. I'm not saying you have to go with the Harley tuners as there are a lot of different tuners out there, but from my understanding once you increase the flow with performance slip-ons and with a better breather, than the ECM has to be tuned to optimize results. If you only change one of the two (breather or slip-ons) than no tune is required. Just my two cents worth.

 

What he Said!!!

 

the thing I struggle to understand with these dyno numbers is, the bike is sitting inside with fans blowing towards the intake..is that a fair simulation of a bike going down the highway at 70? I imagine the stock intake at highway speeds is getting plenty of air, then the argument becomes well then the freer flowing intake would get even more air...but where does the point of diminishing returns on a stage 1 engine come into play knowing the freer flowing A/C provides enough air for their higher stage kits?

 

Thats Deep, Lol

I bet as soon as our weather turns you wont even give that another thought!

 

you got that right, 300 miles in 3 months cuz snow and ice and rain and wind...got about 15000 miles of riding ahead instead of the gears spinning in my head!

 

Nothing wrong with wanting better filtration.. The KnN will get the big pieces but not the real small stuff. I won't run one on a dirt bike especially on 2 smokes.. Only oiled foam there..

I understand the intake noise issue..

Still the top end looks like it will go at least 70K with KnN and the top end on my RK will likely get changed before wearing out..