HarleyTechTalk

Technical Forums => Milwaukee-Eight => Topic started by: deerjoe on April 15, 2020, 07:31:16 PM

Title: 2 into 1 into 2 mod
Post by: deerjoe on April 15, 2020, 07:31:16 PM
Dont see why this shouldnt be a good power add and weight reduction... I have a couple friends who plugged their crossover pipe off with a freeze plug and swear theyve gained a little power.  Im doing some upgrades on my '17 SG and Im running a V&H power duals header with SE street cannon slipons.  Im getting 110/130 out of my Fuelmoto 117 upgrade and a Woods 22x cam.  I just got a HPI 62mm TB to put on, and am thinking of other ways to further improve hp/tq, and think a 2 into 1 exhaust would help.  Anybody here think blocking off the crossover with a plug and removing the left muffler would be a feasable way of accomplishing that?  Im thinking it would... thoughts?  Thanks for any input...
Title: Re: 2 into 1 into 2 mod
Post by: FXDBI on April 15, 2020, 08:27:07 PM
I think if it was such a good idea and worked so well more people would be doing it, never seen or heard of it done on any bike before.  A proper designed and built 2/1 would most likely give better results. You might find you lose low rpm torque with that large of a TB. Low speed manners may  be shitty unless a extremely talented tuner sets it up. That's a lot of TB for a 117. Science projects don't always turn out for the best.  Good Luck...Bob
Title: Re: 2 into 1 into 2 mod
Post by: Tail Ridr on April 16, 2020, 02:54:50 AM
I see no mention of core size of these mufflers used but If they're running 2.5 inch cores on the mufflers, I could see where the butt dyno shows more response to the low end by adding some back pressure albeit what the real numbers show as the revs increase. More info maybe...

I'd also have to ask what AC you're using now and what you'd use after the 62 HPI upgrade...is there a restriction with some parts not playing well together?
Title: Re: 2 into 1 into 2 mod
Post by: goose2 on April 16, 2020, 04:54:34 PM
All I know is the D&D Billet cat 2-1 works really really well on these M8. No doubt probably the best pipe set up for the M8 but also one of the most expensive. I guess you get what you pay for.
Title: Re: 2 into 1 into 2 mod
Post by: Hillside Motorcycle on April 28, 2020, 04:10:06 AM
Had a customer come in that de-catted his pipe, and plugged /welded the crossover, and installed a Thunderheader muffler.
We bored his 107", to 117" and installed an S&S .475, only.
Great dyno results, and no evidence of anything odd/wrong with his exhaust system.
Title: Re: 2 into 1 into 2 mod
Post by: Sunny Jim on June 18, 2020, 06:45:05 AM
Scott, what size baffle did you use on that thunder header?
Title: Re: 2 into 1 into 2 mod
Post by: Hillside Motorcycle on June 19, 2020, 03:34:51 AM
I do not know.
The customer had built this nice configuation.
Title: Re: 2 into 1 into 2 mod
Post by: joe_lyons on August 12, 2020, 05:21:36 AM
Just got done with a 107 with CR480 cam and I decated the headpipe and freeze plugged the crossover because he had krome werks mufflers with the god awful baffles and had a pretty good result.  I would not do this with SE mufflers. 
Title: Re: 2 into 1 into 2 mod
Post by: Sunny Jim on August 12, 2020, 06:50:35 AM
Joe, what size / type of baffle did you use?