Exhaust Options

[dave_a]

Guys, I am thinking about replacing my 1.25", rusty, wrapped head pipes with the "original Mike's" performance oriented 2 into 1 exhaust. He claims a HP increase.

Can anyone tell me if these can fit my '74 - what challenges cause these to fit 80-84 models only?
Is there a performance increase on a stock '74?
2 into 1
Also considering this muffler. Is it quiet enough for street use?
Reverse Cone Muffler

Thanks in advance

 

[rideitfast]

The Mikes system is made by https://delkevic.com/ and I have it on my XS.

 

[RC4MAN]

The mounting issue is probably muffler attachment points variation in frames

 

[jetmechmarty]

The mounting issue is probably muffler attachment points variation in frames

What about clearance for right turns? It looks like the pipe will touch down before the foot rest.

 

[dave_a]

Just to be clear, my 2 into 1 isfrom XS650inc. (Not Mike's.)
It's head pipes to a collector, not a "system"

 

[rideitfast]

Just to be clear, my 2 into 1 isfrom XS650inc. (Not Mike's.)
It's head pipes to a collector, not a "system"

Got it. Sorry I got that wrong. When I saw Mikes I automatically thought MikesXS.

 

[dave_a]

What about clearance for right turns? It looks like the pipe will touch down before the foot rest.

I already scrap the side stand ball on the left side. Hopefully some real world experience on the Lelonde pipe?
A pair of Commando mufflers is my other option. Very little difference in price between the 2 into 1 with muffler and a pair of Commandos. If I get free HP even better! But I can't turn left all the time!

 

[RC4MAN]

On my street tracker build years ago I ran both a Hooker 2-1 and later right side half mile pipes with Super Trap mufflers. Both would touch down in right hand turns.
On future builds I'll be using either high pipes or duals tucked in with individual mufflers

 

[5twins]

I prefer a 2-into-2 system. 2-1 systems can be difficult to tune for because most are made to just fit the bike in question. Header lengths and collector size are often not ideal. So, I go with 1.5" headpipes and Commando mufflers usually. I do have actual Norton Commando Peashooters on one of mine and while they look very nice, I think I like the other Commando mufflers better.

 

[dave_a]

5twins and all,
Is there any real benefit to swapping out the OE 1.25" headpipes to 1.5"?
(Then to a pair of Commando mufflers)
I'm just riding not racing.

 

[5twins]

The 1.5" headpipe is supposed to be the ideal size for this motor, not too big and not too small. The O.E.M. 1.25" pipes are rather restrictive, and larger 1.75" to 2" pipes rob low end and midrange power, only making good power up near redline. You can add inserts to the larger pipes and get some of that lost power back, but that's more money you're spending on top of the pipe cost. I actually have homemade inserts in my 1.5" pipes on one of my bikes, and I think they help even on the 1.5" pipes. This motor likes a small diameter headpipe for best flow, at least for the first few inches up by the head. The inserts "fool" the motor into thinking that's what it's got. I'm in the process of making up another set for my other bike. I think the one with the inserts just plain runs a little bit better, so I want to see if adding them to the other bike results in the same thing. But, it could be because I ported the one with the inserts installed when I did the topend, lol.

 

[Kevin Werner]

5twins and all,
Is there any real benefit to swapping out the OE 1.25" headpipes to 1.5"?
(Then to a pair of Commando mufflers)
I'm just riding not racing.

A new friend rode my Red Bike, 1.5 pipes, commando muffs and VM34s and mentioned my bike felt faster than his stock XS650. Truly time slips are the only quantative verifier or dyno runs. I enjoy how my XS650s behave between 3000 and 5000 (5500) rpm.

 

[jetmechmarty]

Somewhere in this data is the optimal size exhaust for street riding. I think it’s 1 3/8 inch. It’s about scavenging speed. It’s like the garden hose with the water falling out of it. Put your thumb over the end and the velocity goes up a great deal. Or increase the pressure at the source. The two inch exhaust pipes works well somewhere well beyond our redline.

 

[5twins]

On the 1.5" pipes, that's the O.D., so the I.D. is probably about 1 3/8".