I have a M900 with the factory head pipes and collector, and some high slip on muffler's.
I'm thinking of installing the aftermarket mufflers down low, mimicking (more or less) the stock setup.
I would guess that the factory pipes and collector are pretty efficient. Yes/no? If not, what would be your suggestions for an exhaust system? Individual pipes, or 2 into 1?
Thanks, Danny
I have sil-moto equal length (sometimes called spaghetti) headers on my M900 with the sil moto / ncr titanium low pipes.
i love it.
the collectors are lighter than stock and the cross-over is a much better design. I had mine ceramic coated to cut down on heat as well.
Spark and Sil-Moto both make these kinds of collectors and the benefit is in top-end hp.
The stock system is not bad though and not necessary to change. If one wanted to go to a 2-1 system, it would require some doing, as there is not an off-the-shelf header for that. If you did go this route, you would not be alone, however, as I am doing that on my 'other' M900 with a single Arrow c/f high mount exhaust. (dare to be different, they say).
G'day am
I spend alot of time looking at pictures of your bike. There's so much to check out. Definitely a 'five beer' bike.
Much hp gain with the spaghetti system? How different is it to the old DP system for M900s?
I've seen a dyno chart (MPS/Doug Lofgren) that showed a spaghetti system making only 1 or 2 more peak hp than the stock system. I think it was the DP system. I was surprised how well the stock headers worked since that collector looks restrictive but must actually be quite effective. The dyno chart showed how the spaghetti system held onto the power longer to slow down the drop off at 8-9000 rpm. So while peak hp gain wasn't impressive the hp gain was significant where it tapers off for a 2 valver. Quite useful for racing, but not enough bang for the buck for the road.
Brad Black shows dyno evidence on Bikeboy site that a 2 into 1 system on a large capacity twin can sometimes be a performance step backward due to lack of muffler volume. Personally I like the loss of weight and clean look of a 2 into 1 on a SSS bike. What I find interesting is that DP make a 2 into 1 for the HM which with the DP ECU gives a 6hp gain over stock (JD Hord).
I'm guessing the more 'worked' and bigger the capacity the motor is, the more effective a large bore spaghetti system will be. Fair rationale for hotting up the engine [evil].
I remember Staintune made a larger bore copy of the stock system with a more free flowing looking X collector. It was highly polished and the collector had nicer radii and more volume to match what appeared to be 42-45mm pipes. It's on my wish list.
The spaghetti system does add cornering clearance over the stock headers, another +.
The 2-1 system on the other M900 is more of a "why not" than a solution to any problems or a means of accomplishing more performance. (Though it is a considerable weight loss compared to the two low reverse megs that this bike had on it when we picked it up)