Finally...
... After about 40 hours and $800 in parts, the duals are on. Approximately $250 of the various excess reducers, flex joints, clamps and spare mufflers were not used.
Construction. The plumbing was built from scratch from 2"OD pipe, various reducers and odds and ends. Each side was individually cut, assembled, fitted, welded or clamped one step at a time and consists of between 9-12 individual components... each. The 2" OD pipe was exactly the right ID size (about 1 7/8") to continue to use the stock upper slip-joint gaskets.
Update: I "re-made" the two L pipes which exit from under the bike out of 2.125" OD pipe. The ID of 2.0" allows for a good, close-tolerance slip-joint and the elimination of one weld on each side.
"Gasketless" slip-joints, sealed with high-temp RTV, and band clamps were used for the sections as they emerge from the sides of the bike. With little work and expense, new "L" sections can be fitted for other mufflers if desired. The GSX-R1000 mufflers use triangular flanges with a 3" bolt pattern welded on to the pipe... a little different from the other mufflers I have used.
Sections from three of these were used on each side:
Hangers were made from 3/8" steel rod. They are suspended much the same as the stock... except with two rubber isolators instead of one. The stock, single frame-welded hanger accepted the extra rubber isolator rather nicely.
The pipes exit from the bike's sides about 4" further forward than the standard right-side elbow so that approximately 1.5" of vertical clearance was provided for the drive belt (on the left). The belt side was built first to allow for this clearance and then the right side was "mirrored" so that the upward angle for the pipes/mufflers would be the same.
Full-length heat shields from the same perforated aluminum that was used on the SuperTrapps will be made at a later date. The shields will cover only the "L" portion of the pipes exposed to view on either side.
The right pipe houses the stock O2 sensor. If needed at a later (much later!) date, a cross-over pipe connecting the two sides can easily be constructed... or the evoluzion.net O2 sensor eliminator can be reinstalled... or the Two Brother's Juice Box, which I ordered from No Magic Neon a while back, can be used.
Exhaust flow should be better than stock. Only three 90 degree turns exist on each side of the new pipes. Including the final 90 degree elbow on the stock setup, five turns exist for the right side pipe... and just three for the left.
The stock 2-to-1 is on the left... the upper slip-joint gaskets which occasionally give us trouble are at the top of the two intakes. The new plumbing is on the right.
Mufflers. The mufflers are from a 2008 Suzuki GSX-R1000. I had to buy two sets on eBay to get one decent set. Even so, these are a relative bargain at $75-100 a set as they are titanium, stainless steel and aluminum. Replacements from Suzuki are about $900 per side.
The mufflers' stock hang/mounting points were used but... the bolt holes did need to be enlarged.
Two big pluses: there's no glass or ceramic packing to wear out - only stainless chambers... and each side only weighs about four pounds.
Sound. The sound is distinctively different from the stock 2-to-1 setup as you can hear each cylinder individually (think Ducati Monster with non-stock duals). The noise level is a tad louder than a Hindle but nowhere near as loud as a Micron... it's very similar to the dual SuperTrapps (earlier in this thread) with four diffuser disks each.
The GSX-R1000 (but not the Spyder) also uses a central muffler box under the engine which contains the catalytic converter as well as additional baffles.
I had no clue as I was buying/building what this set-up would sound like. I got what I was hoping for... out of sheer luck.
Finally, there was one casualty after the build was over. The
cast aluminum foot guard at the driver's right foot peg appeared to be a little crooked. So...if you think you want to straighten one of yours, think twice. It didn't take much... just an outward tug... to break it. :yikes:
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