I love the look of these mufflers and have been looking for info on these for a while (as well as many other brands) to no avail. Three is something about the slash 4-1/2" end cap that is really bad ***. So, I decided to call and got a Harley specialist at Magnaflow who told me this:

• They are designed to be slip-on's and work with the stock setup.
• They do increase HP and TQ slightly but mostly provide better sound

I told him that my concern was opening the exhaust too much and causing a lean situation without the addition of a tuner. I also said that during the design and testing of this product there had to be some data gathered. He said he was going to talk to R&D about getting some charts or other info that would he helpful to the consumer so that we wouldn't be flying blind on these things. RCX has a A/F chart on theirs with stock bike and S&S states that theirs adds 7HP (no dyno chart) but other than that there is nothing out there for most exhaust.

If I do get that info I will share here on the board and did let him know that was my intention. If anyone has already been through this, please post up numbers so the rest of us still looking for OEM replacements can make a better informed decision.

 

I do not have numbers from a dyno but can say from running all 3 slip ons you've mentioned on a 2017 Street glide with high flow ac, tuner and decatted stock head pipe my butt dyno could not tell the difference in any of the 3, sound wise, yes there was a difference but otherwise seemed like a wash to me, others may disagree.

 

I have a set on my 18 Road Glide...no numbers but didnt notice any power gains...just good sound.

 

Per an email response from MF:

"On a stock 2017- up M8 Motor you should see 5-6 HP gains and 5-7 TQ gains. This would be the approximate numbers as well. Considering elevation, riding conditions and style those numbers can change slightly."

There was no supporting data, just the tech response to my inquiry.

 

These people need to put the crack pipe down.

 

Yeah those are "marketing numbers" for sure, magnaflow however, are the best sounding slip ons I have personally ran out of 6 sets on the M8.

 

i installed a set of the Hitmans on my 2017 RGS, Sound is probably the best i have heard, very deep bass, i just recently installed the stage 2 torque cam with Fuel moto 2-1-2 Jackpot header and coulnd believe how much better they sound, As for 5-6 HP gains i couldnt care less, bike feels great and pulls good so i am happy

 

I pulled the trigger on a set anyway, Crack pipe or not.

 

Added an FP3 to the list and both the mufflers and the tuner should be in today. I hope they are there when I get home. It would be hard to have to have them at my house and wait to put them on.

 

That's awesome! I just installed the Hitmans on my 18 RGS with the Fullsac MX headpipe. Love the sound! They have a nice deep bass to them!