I have not been in for a bit, but I wanted to share something with you Ninja 250R riders in case you're interested:
Over at the other forum, I spent a lot of time grumbling about the paucity of aftermarket exhaust option for us. After deciding that I prefer dual cans, and having had a bad experience trying to get a TBR system, I decided to build my own. Thus far, I'm exceedingly happy with the results, both aesthetically and functionally, so I wanted to contribule to the knowledge base here. The following is what I shared on the other forum:
As promised, here is a preliminary procedural write-up and materials list for the custom Supertrapp exhaust system that I just completed on my bike:
- two Supertrapp universal application race cannisters with discs and caps, with 1.5" ID inlet. They come with t-bolt clamps, 8 dics, end caps, and weld-on hangers (which I find unsightly and did not use.) They are about $150.00 each at MAW Online. I wanted new ones.
- a set of "doner" stock cans, preferably painted (non-chromed), as you will have to weld your extensions onto your mids. You are interested in the midpipes, which you will cut off the cans. I found a pair for $50.00 on Ebay.
- enough straight pipe to extend the doner midpipes rearward by 6"; give yourself a buffer. The local Midas shop did mine. He used pipe that is the same diameter as the midpipes and expanded it slightly where it overaps the mids for consistent pipe diameter back to the mufflers, and welded the new material onto the doner mids. It cost me $20.00 for pipe and his effort.
- two 3.9" (max. diameter) stainless steel t-bolt clamps from Summit Racing. I used rubber insulators under mine that I'd had from a set of muffler straps that were too large. About $11.00.
- two rubber exhaust hangers from Pep Boys, about $4.00 each. They are oblong and have holes 2" center to center. You'll use these to mount the Supertrapps to your existing rear peg brackets. The bottom third of the hanger will need to be narrowed by 1/8" (on the inside) to accommodate the bolt in the t-bolt strap and two washers; this is easily done with a small hacksaw and a ******* file to neaten the cut.
- two stainless bolts/nuts just like your stock cannister hanger bolts, but 2" in length to accommodate the new rubber hangers. You'll also need two appropriate fender washers for the back side of the rubber hangers. Nickle and dime hardware.
NOTE: The biggest - and really only - headache I had while building this system was the infuriating paucity of aftermarket cannister straps that are less than 5" across. Not everyone has cannisters the size of trash bins, for crying out loud! But the t-bolt straps are attractive and work well.
Begin by cutting the midpipes off your doner cans. Make sure you cut them all the way back to - but not including - the weld. Clean up the edges. NOTE: If you hold the cut mids next to one another the way they'd be on the bike, you'll note that the clutch-side one has a very slight "leftward" angle at the rearward edge that's about 1/4" inch long. KEEP IT. Your factory left muffler has a built-in accommodation (at the conical entry) for the final drive and left swingarm that is barely perceptible in your bike's stock symmetry. But with shorter cans that do not have this built-in accommodation in the left side, it will be. What you're going to eventually do is swap the mids, left for right, when mounting; doing so will allow you to establish a very near-symmetrical aesthetic balance in your new system, as well as accommodate your sidestand and centerstand just like stock. Try that with a Muzzy or Yosh! Two Brothers Racing claims to have an accommodation for your centerstand, but you could be drilling your Depends in a sunny seat in the Three Slippers Nursing Home dayroom, and hoping for a nurse who looks like Heather Thomas of The Fall Guy, before you actually receive your TBR system! Why wait? Build your own!
Go to your friendly local welder or exhaust specialist and ask him or her (female welders are hot!) to add 6" to the rear of each of your mids. The OD of your mids is 1 3/8", I believe. Ask your welder to use the same diameter pipe and to heat/mechanically expand it to fit over the cut mid before welding. This way, your newly extanded mid will fit inside your Supertrapp inlet without issue.
Dress your completed mids and stock clamps with a flapwheel for painting with low-gloss high-heat ceramic exhaust paint. You could powder coat them, but it's pricier. I'm just watching mine for any undue blistering right behind the headers. You'll have a tad of that with any paint. Another alternative is to wrap your mids, which has both aesthetic and scientific merit, I'm told.
NOTE: You may want to mock up your system on the bike now, before you paint your mids.
Paint your mids and header clamps. Let them dry suitably.
Now you're going to do your assembly, assuming that you have unbolted your stock system. Try not to scratch your mids as you do. Remember to swap your mids left for right, and install your mids onto the headers with the clamps over the leading edge of the mids. Swapping the mids will allow you to bring both cans into close symmetry. They should fit snugly. Do not tighten.
Carefully measure the length of your Supertrapp inlets; you should have about two inches of overlap on the rearward end of the mids. Mark your "depth" with masking tape; you don't want to slide the cans up too far and then have to pull them back, marking your paint. That would necassitate the use of invectives, which are possibly injurious to innocent bystanders.
Place the small t-bolt clamps on the cans' inlets and slide them on the mids up to the tape. It's better to mock up both sides and check for symmetry and clearance from adjascent surfaces like the stands and swingarms before tightening any clamps.
Take your rubber hangers and, if they are the 1" thick kind that I used, use a small hack/holesaw to make a 1/8" cut ACROSS the hanger (perpendicular to its length) one third up from one end. Then cut up from the bottom so the you remove a 1/8" "slab" of material. Clean up your surfaces with a ******* file. You are doing this so that your t-bolts, washers, and nuts will fit through/on the hangers with thread to spare.
Place your large t-bolt clamps and rubber insulators on your Supertrapps with the threaded end of the bolts facing the bike. Mount the tops of the rubber hangers to the INSIDE of the rear footpeg brackets; I eliminated my rear pegs since I never ride two-up. You may need bolts longer than 2" if you want to keep your rear pegs. The bolts will be tight going through the rubber mounts. Thread them through with a socket wrench. Secure them loosely with a flatwasher and nut.
Place small flatwashers on the bolts of your t-bolt clamps, pass the bolts through the lower hole of the rubber mounts, place another flatwasher on the inside of each mount, and loosely secure the supplied locknuts.
Now is the time to snug up all joints just enough so that you can align everything for symmetry and clearance. Check to see that your stands and swingarms are not contacting the exhaust except where the stop on your centerstand rests on your left can inlet. Also, check to see that your cans are rotated so that the logos are laterally level, as seen from the rear of the bike. When you are pleased, snug everything up. DO NOT OVERTIGHTEN FASTENERS. Put little rubber vacuum hose caps on the exposed threads of your clamps at the muffler inlets; it's clean and neat.
At this juncture, you may install your discs. The minimum recommended number for each can is four. On my stock motor, I used five to good effect upon dialing my system in. If you have re-jetted, you may need more or less. Install the end caps. Use the supplied anti-seize on each bolt before final installation.
When you are pleased, fire the bike as you normally would. In addition to the improved (and louder, but not obnoxiously so) tone, you will likely notice a perceptible improvement in off-idle throttle response, as well as an improvement to throttle input up on the cam. My motor seems to pull more with less apparent restriction. Your motor may also run a few degrees cooler because the stainless steel 'trapps have a larger diameter, are shorter, and may dissipate heat more effectively than longer, chromed or painted stock cans. I can't prove it but a metallurgist told me that. Many favor stock exhaust (and that's fine), citing the math and physics behind it, but all I can tell you is that my motor seems very pleased about this whole notion of tunable, useable, performance-oriented exhaust.
After you have logged 100 miles or so, check your fittings.
There are piccies below that hopefully will clarify any muddiness in my verbeage. I'll also try to borrow a vidcam that holds more data than my digital camera, and take you for a lil' rip through the Patapsco Basin twisties.
I hope this provides a viable option for aftermarket performance exhaust for us. At the risk of sounding cliche... nothing ventured, nothing gained.