i'm pretty sure they said running the exhaust out the back made the yamaha sleds "balanced" when they came out....and now keeping all that weight up front makes the sled "balanced"....which is right?
Yamacat21
TY 4 Stroke Junkie
Depends on what sled it is. It might be balanced in the nytro chassis to go out the back but in the srv chassis it might be better out the front. Two different animals.snoway said:
i will guarantee you that the power will be down how can you compare a straight, free flowing exhaust to one that bends a 90 degree.
09nytro
TY 4 Stroke God
If you have a good flowing muffler than that 90 will flow just fine
I think the engineers now what they are doing......and how to make it work...
I think the engineers now what they are doing......and how to make it work...
Yamacat21
TY 4 Stroke Junkie
Looks like the pipe on the viper is larger than the nytro and its mandrel bent. There are engineers that get paid a lot of money to make these things work. I'm willing to bet it will be the same or better hp. Until they are released and put on a dyno it's all speculation.
Yamacat21 said:
These sleds will be within 15# of each other and everything but the exhaust weight distribution is comparible so ....same animals.
Alatalo
TY 4 Stroke Master
A smooth bend with the relatively big pipe diameter and bend radius visible in the pictures does not necessarily rob horsepower. Then I would be much more worried about the silencer. Any silencer designed to meet current noise rules is much more of a flow restriction than a smooth bend.dudester4 said:
Off Trail Mike
Gone Riding!
Throttle Jockey said:
Can someone enlighten me. Why have they brought the header so far back only to have it do a 180 and head forward again??
Seems to me it would be easier to turn the header pipes 90 degrees right of the bat and put the collectors somewhere around where the flexible joint is. I was laughing tho, I hear yami is still using the same 3-1 collector on the nytro that it was using in 2006!
The rear facing engine exhaust works (from a heat perspective), but I'm not so sure they are doing the header so well. I've seen some pretty complicated bike headers, and making them "fit" while maintaining performance is normally not a big issue.
OTM
Suckur
Pro
The reason for not having a rear facing exhaust is the gas tank. Have you ever weighed a full tank of gas? That's the reason they are long and low and directly on the tunnel. It's to lower the centre of gravity as much as possible and distribute the weight of the fuel evenly along the tunnel and helps to counter balance the engine. A rear exit exhaust means a high gas tank and increases the COG which would make handling worse. It's part of the reason Yamaha's are so tippy, especially with a full tank.
canadianhunter
TY 4 Stroke Junkie
Do 4 strokes not require a certain amount of back pressure? On at least one Harly exhaust they use restricter plates to adjust more or less back pressure for power/powercurve.
Suckur said:
what ?...isn't alla that viper exhaust plumbing under the fuel tank????....then it does a 180 and shoots vertical for a foot er so and then into a huge suitcase muffler placed at a high CG.
Yamacat21
TY 4 Stroke Junkie
Suckur said:
Thanks Sucker! So again I say two different animals!
Yamacat21
TY 4 Stroke Junkie
snoway said:
That's like saying a cow can run with a horse. They look similar and weigh about the same but guess what, you can figure the rest out.
Suckur
Pro
snoway said:
Muffler is way lower on a Yamacat than a Nytro's gas tank and also the Nytro's muffler. The gas tank is the same on Cat and Viper except for a depression to allow for the pipe. If you can't see how a high 20 lb muffler and tall tank don't contribute to a high COG then you need to go back and do grade 10 physics again. Viper's handling is far superior to Nytro's. I'm speaking from experience, having ridden an entire season on virtually the same sled.
grizztracks
Tech Advisor
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I actually think this exhaust is going to be a problem. A Yamaha engine was stuck into the AC chassis and the exhaust was made to fit into what little space they had. I don't think the exhaust system was thought out very well. The flex pipe is to far away from the engine and the header is bolted to the tunnel. I see the header eventually cracking due to vibration and flex between the engine and tunnel. Most likely at the tunnel mount. Time will tell.
