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H box mod

4K views 19 replies 11 participants last post by  RAFster122s 
#1 ·
I am going to mod an H pipe to get a dual exhaust on my GL500I. I want to put a small baffle in each side to keep the back pressure up hopefuly close to where it needs to be. Jet changes will come if needed. I lfound after killing an H box that I like the harley cans through 2 pipes but in my area no bike shops or parts houses or exhaust shops seemed to have what I needed when I needed. So I talked to Ohm who I gave some parts to which included and H box. He will be bringing it up this week. I will gas weld it all together and braise the cans to the H box parts to keep a clean look since I don't have access to a tig welder. No spatter on the chrome but some brass color will look good as it peaks through lol. Will get pick and let you know what happens
 
#4 ·
He is going to chop the center of the H-box out, install a baffle in each side and weld it shut to give it true duals but keep the flanges ect to make it a more clean looking setup I think, just dropped off the victim H-Box off at his place and BS'ed for about an hour and a half. I well be interesting to see what he comes up with.
 
#6 ·
exactly. which is another reason i didn't understand the original post. if he wants a 2 into 2 with no crossover why not just pipes in place of the h-box. seems a lot easier than figuring out how to hang that heavy box in two sections.
 
#7 ·
seems that no one around my area can supply me with the right size tube. With the way I am going about this it wont cost a dime and I know everything will match up the way I want it to. I have the habbit of doing things myself instead of farming them out to someone else whenever possible. I take more pride when its something I do myself, makes me happy. Thats my reason for doing this.
 
#19 ·
I am scratching my head on this one. I got a pair of Harley cans and am looking at mounting them as well. Was in the auto parts store to look over their stock of adaptors. What I want to do is leave the muffler gaskets (#14) in place and sleeve the Harley cans back a bit to make the hangers (without adding in another piece of steel strap to hold it in place). I have gas and MIG at my finger tips.





[attachment=215:muffler gaskets.png]

Perhaps the sizing adaptors will make this all work. I'll take pictures when it comes time to build this.
 

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#8 ·
My solution only different I made a two into one. but I'm too stupid to know how to post the picture. Anyway I think the CX500 as most twins do need a crossover pipe of some sort to help scavaging. You may notice a drop off in performace? I like donig things my way too so have fun.

Cheers, 50gary
 
#10 ·
ok so this week I cut down the H box and found that I realy didnt need to add anything to up the back pressure. The inlet has a restrictor around the pipe on each side. I cut the center section out, cut the pipe about 3/4 inch deeper than where my cover plate is welded. I just used 14 gagesteel plate to seal u pthe huge gaping holes. With the way its done it will look stock unless you look under the bike. Next is to figure out if I nee to make any mounting tabs to keep it all in place, or just weld it solid since I am dealing with two pipes and no conections
 
#12 ·
Well now that the honey do list is down to a managable level, and the honey is wanting to ride again. I have laid out the exhaust and made all the marks that I nedd. Tomorrow I start welding it together. All I want is that one little thing that you look at and say thats not right but looks right. Just to make itthat little bit o mine that you just can't buy. That thing that makees it my own little monster. If it brings a gremlin I can deal with it. It will look stock to the harley cans but not quite.
 
#15 ·
Photo's to come soon. Still need to get 2 clamps for the exhaust, where the header mates to the hacked H-box. I did take it for a spin and I really like the note it has now. Power loss seems to be nill but without the clamps not going far. I want the clamps before I take the pics so I can get the pipes to hang right and not stress the conection, resulting in an exhaust leak. This is the first time this bike hasn't had leak lol.
 
#16 ·
[attachment=211:CX500Exhaust-l.jpg]



Here is a rough idea of what I did. I cut the center out and trimed the cross over pipes back as stated before. I did what I could to keep a decent amount of back pressure in the system. This is my shakey finger on my laptop to mod the drawing.
 

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#18 ·
Just a thought.As the collector box balances the different lengths of the exhausts by virtue of the engine design not being symmetrical to get a fully balanced exhaust system you would have to possible extend the right hand silencer/tube?
 
#20 ·
The cutaway drawing reminds me of the "beer can bazookas" we used to build as kids to launch tennis balls at high velocity. Lighter fluid as the propellant.

That was before they went to aluminum cans for soda and beer cans had already made the transistion for the most part.



Firing a tennis ball a couple hundred feet away or trying to drill your buddy that was 75 feet away...ah the good ole days...



David
 
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