I don't mean this to sound negative, just hoping to learn something. I know Husky has done it in the past and Honda more recently. It just doesn't seem like there's much to gain from one header and two cans. Plus it's a fair amount of weight at a high location. Seems odd since I've seen owners of KTM 950's doing a two into one mod for their exhaust to save weight. And those bikes are twins so I could see how they benefit from dual exhaust.
sound, lots of silencer suface area and space for gas expansion to cool (give up heat) the exhaust and reduce noise while maintaining a decent flow.
Just for sound emmissions in theory 1/2 of the sound is on either side of the bike. Also gives more room with 2 silencers to double the sound deadning properties be it mechanical or absorbition (packing) 2 littles hole flow more than 1 so for HP? not much. Honda did it saying it was for weight centralization BS. Later George
What I want to know is if you can buy just one of the aftermarket arrow cans for the new 630 and use it on the 610 ? They have a beautiful Husky gun sight design to them --> pic <-- Would love to do that if it won’t be too obnoxiously loud
they look about 40-50% the size of a regular can, I bet it is loud, hot and wears out quick on your 610. Thats a wild ass guess.
That bike has two headers. It's easy to see in the picture below. It makes more sense on a bike with two headers.....especially a race bike. Taking one header and efficiently splitting it into two cans doesn't seem like it would be that accurately done. I say the one can on the side of the header will get far more use. Sound is a logical explanation but I just don't buy it..... The reduced sound vs. the additional cost vs. the cost of just one can.....I'm thinking like the Honda explination, it's marketing BS.
Ah. It does. I was thinking it didn't. But does it extend all the way to the can? It kinda looks like it goes two-into-one then back to two. That would explain a lot.
Im pretty sure the 2 exhaust ports coming out of the front of the head have gone from the size of 20c pieces to the size of tennis balls and would therefore need massive flow. In this scenario you could run 2 large diameter pipes back. It will increase top end power when the head is flowing at its maxumum. However.... On our measly Husky's 610 or 630 the heads would not flow anything like this so they will be wanting more low end torque hence the 2 into 1. Going back into 2 mufflers will definitely decrease power if you open the diameter of the mufflers up. Exhaust diameter is critical for flow and extraction of exhaust gasses from the combustion chamber. Too big and the gas will puff out leaving exhaust gasses in the combustion chamber, slowing the rate of burn for the next air fuel mix in the cycle, instead of being drawn out at a faster rate, leaving the combustion chamber clear of exhaust gasses. Without proper exhaust gas extraction you also lose power with unburnt fuel left in the combustion chamber which also leads to carbon deposits on top of your piston. This will eventually lead to run on. Stu
On the Dakar bike it's because of the massive size of the main tank and the location of the auxiliary fuel tanks.
I was thinking it was to increase the surface area of the catalyst for emmissions. 100% guessing though...
Judging by the size of the single cans on a G450X or G650X for instance, which are quiet, the duals allow a less chunky way to get similar sound reduction. Frankly I am just waiting for someone to part with their duals so I can buy them cheap and mount on my 610. The noise really is harsher than it ought to be.
Just guessing... Aside from the extra expansion volume and cooling area, maybe there is also an advantage in pulse timing. Two pulses arriving at the tip slightly out of sync resulting in a lower peak SPL. Two cylinders for the price of one. Cheers, Numbers
Why should 2 in 1 be a power boost? The larger the flow area (diameter) the more fuel/air can be fed to the cylinder (s). A single can with as much flow area as my twin Arrows would have to be enormous! Bike owners with a single can seem to prefer two and owners of twins seem to want a single. Maybe it´s just an impulse to be creative and modify what´s there.
