The logical next step to jetting and after market air filters is an after market exhaust system! Although there are many choices, this author favors the Supertrapp Exhaust System.
The Supertrapp E.A.R. Series Exhaust System is designed for Dual Sport or Off road riders requiring a low exhaust sound level.
Supertrapp research claims a gain in power of seven HP on dyno testing with a XR600R. The system is about one half the weight of a stock system and meets all EPA legal sound requirements. The body is constructed of aluminum with a steel connector pipe. The system uses a series of plates that you install into the end of the exhaust to control exhaust flow and sound levels. Most people find six or seven plates or disks to be about right using a K&N air filter and Dyno Jet kit.
Installation is very easy. All fittings are of good quality and "fit and finish" is exceptional. It should take no longer than one hour to install the system!
One thing to keep in mind is that this exhaust emits a "doughnut" shaped exhaust and the heat from the exhaust has a tendency to discolor and melt a small section of the rear fender adjacent to the end of the pipe. I simply cut away a very small section of plastic from the rear fender and solved that problem!
The Supertrapp system can be ordered through your dealer or White Brothers Catalog. Supertrapp has a very informative Web Site that would be helpful when considering an after market exhaust system.
Want to take a guess on what is the most popular modification to motorcycles? You got it, after market exhaust systems. I have always had mixed emotions about after market mufflers and exhaust systems. I like the idea of more power and reduced weight, but do not like the noise factor that comes along with the package. Supertrapp has been making exhaust systems for motorcycles and four wheel vehicles for many moons now and have sold their external disc series mufflers successfully in a variety of applications. Unfortunately, the external disc series could never really control sound adequately and the way in which the discs bolted to the muffler body resulted in stripped bolts and soot covered bodywork.
All that would hopefully change, however, with the new Supertrapp
IDS series. Supertrapp boasts that the new IDS series has the
smallest overall diameter of any after market four-stroke muffler.
Supertrapp engineers will also tell you that the new IDS series
will not have the stripped bolt syndrome that plagued the external
disc models since the discs are enclosed in the muffler body,
protecting them from the elements, and only three larger bolts
are used to secure the discs to the core body. I was further encouraged
by the engineer claims that the IDS Quiet Series is much quieter
than the E.A.R model and that the IDS system was tested and perfected
on a KLR650.
With all of this in mind, I decided to give one a whirl, so I ordered up a Supertrapp IDS Quiet Series muffler for my KLR. The package arrived a few days later with all of the components packaged neatly and a set of comprehensive instructions. Interestingly, the system comes with ten diffuser discs although the instructions say that no more than eight discs should be used on the Quiet Series muffler. The muffler is easy enough to assemble with the nifty Allen wrenches supplied with the muffler, be sure to use plenty of anti seize on all of the bolts. Hearing other riders experiences with the IDS, I decided to remove the cheesy Supertrapp sticker from the muffler. A few minutes with a heat gun and the sticker peeled right off the muffler body. Imagine how long it would last on a hot muffler. If you leave the sticker on it will leave a discolored mark from the glue baking on, so just remove it and clean the area with a good solvent.
With the muffler assembled, I was ready to install it on the bike. The intermediate pipe that joins the muffler to the header pipe fit up snuggly, but I applied a thin bead of high temperature silicone anyway to ensure a leak free joint. Now it's time to fit up the muffler and this is were the problems began for me. No matter how I positioned the intermediate tube, I was unable to position the muffler far enough away from the rear fender. No problem, I simply made a spacer and loosely mounted the muffler to the rear subframe. Once I was happy with the positioning of the components, I tightened everything up, which led to problem number 2: the muffler refused to tighten up to the intermediate pipe. Even with the clamp at tight as I could get it, the muffler would still jiggle on the pipe. A generous bead of high temp silicone took care of that problem and 24 hours later, the 'trapp was ready for testing.
I should mention that my bike was rejetted prior to this test and that I think rejetting a carburetor is necessary when adding any after market system no matter what the manufacturer says. Thumb the starter and the most wonderful mellow, throaty sound emanates from the brushed aluminum muffler. Blip the throttle and you are rewarded with a deep, robust bark that should be mandatory for all thumpers. Pulling away, I noticed a power increase in the low-end and mid-range, but nothing in the top end of the power band. That really didn't matter, though as dual sports are more apt to need the power in the bottom end than the top. So the IDS Quiet muffler gave the big thumper extra power and a nice sound. Unfortunately, the honeymoon with the Supertrapp was over after a mere 400 miles, when the muffler was not quiet anymore and the lusty exhaust note I heard the first time I started the bike was replace by the sharp bark characteristic of most Supertrapps. I know a muffler like this needs to be repacked periodically, but after just 400 miles, give me a break.
Aside from the degradation in sound and poor fit, the Supertrapp performed well giving my bike a noticeable (seat-of-the-pants) bump in low-end power. It definitely performs better and is quieter (even in its louder state) than the older style, external disc E.A.R series. I should note that other riders have not experienced a fittment problem with the Supertrapp IDS series and it is possible that my problems may be an isolated case. With that said, The Supertrapp IDS Quiet Series is not the perfect dual sport muffler, but it is better than anything else out on the market at this time.
|White Brothers Company can be reached at:
Supertrapp Company can be reached at: