Salvaging The OEM exhaust system

[QBS]

I'm starting this thread on the General Board because of the several muffler/exhaust dialogs that have recently surfaced here.

Several years ago I acquired a rusted out '82 OEM exhaust system from Vnarie Rob (creator of the wonderful Fram air filter replacement system). The purpose of the acquisition was to perform exploratory surgery that would hopefully provide insight as to how aftermarket muffler cans might be adapted to replace the rotted mufflers that so many Vs are plagued with.

My plan was to use a hack saw to cut off the muffler where it attaches to the collector box and hopfully find an internal pipe coming out of the collector that a muffler can could be easily attached to.  Took a really long time to cut through muffler.  The metal there is quite thick.  But, I eventually persevered and did cut off the muffler only to find that at the location where I cut through, the collector box is hollow with no internal pipes of any kind in sight.  At this point I knew what I had worked hard to learn.  I dropped the project, concluding that an aftermarket can could not just be easily clamped on after minor surgery to the stock system.

Then, earlier this week, comments regarding various welding techniques and someones apparent off hand remark to the effect that an adapter could be welded onto the stock collector box, made me conclude that the best fix for rotten V mufflers is indeed a stock collector box adapter scheme.  V collector boxes rarely rot out and fit the engine perfectly so using them as the foundation of the exhaust system makes a lot sense.

Here's how I see it working:

(1) Use a hack saw blade equipped SawzAl to cut off both factory muffler cans right where they are welded onto the collector box.

(2) Cut out a disk of thick steel sheeting that is the exact outside diameter of the collector box hole where the stock muffler can used to be attached.

(3) Cut a hole in the center of the disk that is the diameter of the outside diameter of a piece of steel tubing that is the right size for an  aftermarket muffler can to attach to.

(4) Stick the tubing through the hole in the sheet steel disk with enough of it protruding on one side to provide adequate attachment surface for the aftermarket muffler can.  Weld the tube to the steel disk on both sides of the disk.

(5) Weld the disk/tube assembly to the open end of the OEM collector box.

(6) Attach the aftermarket can to the new adapter tube.

(7) Attach the aftermarket can to the stock muffler attachment point on passenger foot peg casting.  Use some sort of generic aftermarket clamp/bracket/brace to accomplish this.

(8) Devise some sort of cosmetic cover that clamps around the gap between the OEM collector box and the aftermarket can.

Also:  Some research may turn up an OEM can from another bike that could be readily and cheaply acquired from the used parts yard and be used in place of a more expensive aftermarket item.

So, what do y'all think?............Cheers.

[Lucky]

i cut the cans off a really rusted out OEM once a looong time ago... i cut then right after the weld (leaving the weld on the collecter)  what i remember is that there was a seperate inner pipe comming from inside of the collector.  i don't remember really how i planned to attach the mufflers i found at Pepboys (which the aparently don't sell anymore) i think i was going to have them welded.. & I designed some baffles for them (on my site)

so although the details escape me now, aparently it was entirely feasable (this from someone with absolutly no experience designing m/c exhausts)

--Lucky

[Hugh]

Wasn't there a write up in the ROV newsletters on how to replace the stock mufflers with supertrapp slip-ons (text and sketches)?  I've never actually seen any of the old newletters, but I bought some parts about 15 years ago from a guy in Wisconsin who had them and I'm pretty sure he said that there was such an article.  Can somebody with the newsletters look through them and verify? 

Hugh

[louthepou]

Back in 1994, I was thinking about cutting the original rusted mufflers and welding a cheap generic straight aftermarket pair. But then I found a MAC exhaust...

I may just try to see if I have a rusted original somewhere around and cut it open to see if that's a plan worth the trouble...

If there's time...

Lou

[Night Vision]

I started cutting off the cans on a rusted set and wore out a cutting wheel on a hand drill. QBS is correct about how tough that metal is. must have taken forever to hacksaw it. I'm going to get a angle grinder some day to finish.

Newsletter 17 (PM Jeff Swan) has the artical to retrofit the trapps. basically used a 6.25" long x 2.5" muffler pipe to slip into the OEM collector. a 2.5" inlet/1.75" core trapp then slipped over the muffler pipe. a bracket was welded to the 2.5" muffler pipe and hung on the footpeg bracket.


suppertrapp no longer makes that specific universal slipon. other 2.5" trapps are in the $150+ each range on eBay....