| Author | Message | ||
     Growl |
I desire a spark arrestor for my Uly. Maybe a Supertrapp? The outlet on the stock muffler is curved and thus doesn't look feasible for mounting a spark arrestor but maybe a modified muffler (Drummer style - except that Drummer won't do it at this time) with an outlet bent to allow a spark arrestor to be mounted and tucked up under the passenger foot peg? Has anyone mounted any type of spark arrestor to their Uly?} | ||
| Strokizator |
I would think that the stock muffler does not require a spark arrestor as do none of the other "off road capable" adventure bikes out there. I'd be interested to know if the stock pipes modified by Drummer & Special Ops retain this feature. | ||
| 911_racer |
my drummer has nothing even close to a screen type spark arrestor. i wish it did because i ride off road alot. | ||
| Red_chili |
Done did it. I like! When I was thinking about this, I got ahold of Odie because he was talking about doing something like this. Odie said he was going to call me but never did after several attempts to contact him. Oh well. Kevin Drum said he would 'not help me build a Drummer', which I certainly understand - but that was not my intent. Oh well. I 'reverse engineered' a Drummer my son's XB9S has, just to educate myself, with an inspection scope and was surprised. The head pipe basically ends about where the stocker ends internally, then the entire interior of the pipe is open. Drummer lines their can with perforated steel and permanent packing, which contributes to the good tone no doubt. Of course, the Drummer is TIG welded and workmanship is quite nice. The educational part was how very little backpressure the Drummer presents to the XB motor. I was going to find some perf steel and do the same thing Drummer did with the sound damping, but I had an afternoon and some motivation so I decided I could always add it if I didn't like the results. I cut the pipe in thirds, in front of the front 'Jackpoint' marking, and behind the rear 'Jackpoint' marking, capturing the bulkheads in the center section. I then used a plasma cutter to remove the bulkheads and three internal pipes. Interestingly the XB12 can I used had the head pipe terminate in the forward chamber, with the center section pipe just meeting it. I thought they were connected. Nice bonus. Clean. I then plasma cut a rear plate out of some sheet steel more or less the same gauge as the muffler and added a bit of exhaust adapter that fit the Trapp perfectly. Then I stitch welded the whole thing together. Turned out rather well. I left the muffler valve in, though it does very little any more. Results? With 13 discs, the note is less 'blatty' than the Special OPS pipe I had, and quieter, but is a nice tone. Very nice surprise; I have had SuperTrapp systems that just didn't sound all that great. It is not quite as 'deep' as a Drummer, but not quite as loud either. The Drummer is aptly named, it has a thud quality. This one (the Trapp homebuilt) is deep, but less percussive. As far as power, I could immediately feel a stronger top end, like it wants to run past redline (this was after letting the ECM relearn the mixture). Not sure if the midrange is changed, but it seems quite strong. I might have to experiment with removing a couple discs - the nice side benefit of a SuperTrapp. And.... it is spark arrested. And dirt cheap. Rolloff leads to less afterfiring than the Spec OPS pipe did, which tells me the pipe has a bit more back pressure than Odie's pipe perhaps - cleaner run with the stock ECM in any event. No noticeable cruise surge either (unlike stock or the Spec OPS pipe, though admittedly this was in the 'barely noticeable' category). What's not to like? I'll have to see how it works with a race ECM when some funds free up. Maybe.  | ||
| Red_chili |
No race ECM... but did use ECMSpy to tweak an '07 map, and burn it. The pipe works very well now, sounds nice without being unduly loud, and was very inexpensive to build. | ||
| Maximum |
Nice job Red! Any pictures of it installed on your bike? |
