3 into 3 exhaust

[YammieDave]

Having bought two Nytros this year, and already going through both exhaust systems due to breakage, I've determined there's an inherent flaw in going 3-into-one and mounting that system to a tunnel that flexes.

Factor in the tunnel icing, and these rear exit systems are my least favorite thing about the 4 strokes.

I'm thinking about building a 3 into 3 system with custom bent pipes using three smaller mufflers. My thinking is that with three separate pipes, each mounted with their own hanger in isolation, they won't be constantly trying to tear apart from one another.

First question: Anyone done this? Please share your story and pics.

Second question, bonus in sound physics: Can three smaller mufflers on a 3 into 3 equal the sound reduction of one larger one on a 3 into 1?

 

[maim]

watching. i have never heard of anyone doing it. from the math though, any 350cc motorcycle muffler and pipe size should get you close performance wise.

 

[Pmtg04]

You will probably lose the scavenging effects that come into play with a collector style header vs individual exhaust pipes per cylinder.

Muffler-wise, I'd think you'd end up with a heavier setup. The stock muffler allows all cylinder sound waves to bang around and lose their energy. You'd need to replicate that 3x, and that'd end up using more material. But, depends on the material used....stock steel vs potential titanium/carbon fiber options out there.

I guess after 11 years of the nytro being available that the aftermarket hasn't really addressed the flex/isolation issue, and maybe it isn't that big of an issue? That said, it doesn't mean it can't be improved when issues are seen on your sleds. Maybe a quality flex pipe to allow for expansion?

I keep wondering about a Viper header with a Viper gas tank and a custom oil tank to redirect the exhaust to the front-right exit. But I feel the nytro is too tight inside to accommodate it all, especially with the battery in the path. I wanna putz with ideas this summer.

I ended up buying a catalytic converter just to try on a stock setup, remove muffler and add cat. It slips on but I haven't even started it to see noise differences, but it weighs less. It was more of a "let's see what happens" because most(all?) aftermarket options come across as too loud. Maybe a possibility if running 3 individual pipes, to run 3 cats? Maybe a cat is a bad idea, not sure how flow compares to stock/aftermarket options. I like to try weird things sometimes when I'm not totally satisfied with what's available.

Lastly, on an old SnoWest thread from many many years ago, some had talked about replicating the stock muffler in titanium, but it never came to fruition. It was something that crossed my mind as well but titanium welding is out of my league!

 

[4strokes]

when they used this engine in the viper, it seems to me the front exhaust lowered the power and I also believe it lead to burned ex valves and hard stating etc... alot of vipers had lost all their ex valve lash by 10k where the nytro easily lasts the 25k recommended

 

[Gone Blue]

These flex couplers sure seem like the way to go on all Japanese built Yamaha's. Wish I had seen them before I put on copper donuts. G.B.

https://ty4stroke.com/threads/apex-donut-elimination-mod.154719/

 

[YammieDave]

I've been doing a lot of reading on this, and have no conclusion yet.

I'm planning on doing this as a summer project anyway, so I was just looking for feedback at this point.

One thing I failed to mention is that my Nytro has an MPI stage 1 supercharger, so that also changes some of the variables such as flow and scavenging. I'll keep this thread updated with what I learn, and if all plans out, what I build.

 

[YammieDave]

Gone Blue, I do intend to build it with those flex pipes to eliminate donuts.

 

[YammieDave]

Pmtg04,

I think I can still save weight with a 3 into 3 over stock. That stock system is heavy.

And, if I can build it to reduce tunnel icing, that will pay back in spades on weight.

Also, regarding your note about the aftermarket not offering a 3 into 3, it's a good point, but I'd also note that aftermarket development for these sleds is all but done.

I'd love to consult with an expert in exhaust design. Maybe I can pull it off.

 

[Jeffz]

Gone Blue, I do intend to build it with those flex pipes to eliminate donuts.

Check out https://www.fxgarageworks.com/ for flex pipes for 4 stroke Yamahas.