Has anybody done a non turbo under tunnel exhaust on the Nytro? Are there any clearance issues with the suspension? Would like to see any installs or descriptions of installs, pro's, con's, problems, issues, etc...
Under tunnel exhaust
- Thread starter Timber700RMK
- Start date
saw a guy with a stock exhaust off a YZ450F dumped under the tunnel. Not that complicated just take it to a muffler shop
I have seen some slip-on exhausts like Excell & such, but is all it takes is some tube bending and just mounting it up under the tunnel??
on my vector all i did was cut it at the "Y" and just tinkered with a Yosh slip on pipe to make it fit. Any muf shop would do it
as far as i can assume, 4 stroke exhaust is no where near as finicky and picky as a 2 stroke exhaust. where pipe and can needs to all be 'tuned' together. a 4 stroke does still need a proper back pressure or restriction, weather it be turbo or muffler.. 
example, when i was younger and though straight pipes on my 350 S10 was "cool", it ran worse at the drag strip, and towed worse, compared to a dual muffler setup. again, depends on how restrictive other parts of your exhaust may be. as in, maybe a single exhaust straight pipe, or a smaller diameter exhaust would have been enough restriction to allow for a straight pipe setup to work 'better'. maybe there were intake limitations, and so on..
i guess put simply, no, there shouldn't be much more to it than a different muffler (that fits in the tunnel) and bending some tubing to route and hang under the tunnel instead of the top.. You really shouldn't even need to add too much extra tubing either. a flatter or more rectangular design may be of more benefit for the under tunnel setups, for clearance and being out of the way.
example, when i was younger and though straight pipes on my 350 S10 was "cool", it ran worse at the drag strip, and towed worse, compared to a dual muffler setup. again, depends on how restrictive other parts of your exhaust may be. as in, maybe a single exhaust straight pipe, or a smaller diameter exhaust would have been enough restriction to allow for a straight pipe setup to work 'better'. maybe there were intake limitations, and so on..i guess put simply, no, there shouldn't be much more to it than a different muffler (that fits in the tunnel) and bending some tubing to route and hang under the tunnel instead of the top.. You really shouldn't even need to add too much extra tubing either. a flatter or more rectangular design may be of more benefit for the under tunnel setups, for clearance and being out of the way.
That sounds logical. I was wondering if there is any clearance issues with the suspension under full compression or is there enough space under there where it wouldn't matter. Has anybody run into problems with snow clogging the exhaust flow?
Anybody have pic's of their under tunnel exhaust????
I've built a few for Rx's and I also built one for my Vector (now stolen if anybody happens to see it) but from what I've read and talked to guys who've done them on Apexes is that the fuel injection doesn't react well when the snow gets up into the exhaust. Physically building the under tunnel on the Nytro would be a snap getting it to run right in powder might be a different thing. Clearance would be no problem. I may just try it and see what happens.
M5
M5
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lucky13
Active member
i built my own out of titanium, i removed 13.2 pounds, and put 2 of it back. the od is 3 inches and there are no clearance problems, the one problem i have had is it allows for to much snow and ice build up, this summers project on that will be to make it so it exits out of the side, that should eliminate the ice problem
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portgrinder
Well-known member
Neils Power Pipes makes them. Check out his site.
I mounted a Kerker slip on from a R1 street bike. Sounds much nicer. Haven't had any problems with snow plugging it up and no problem with clearence, but I think I may have performance issues that I am working on. I seem to be short on power at the top end now. Because of the EFI, it has changed a few things, unlike my RX1 when I put on the Cherry bomb under tunnel.
I am hoping to play with the CO controls this weekend and will let you know what I find.
I am hoping to play with the CO controls this weekend and will let you know what I find.
Thanks. I don't see why one couldn't just straighten out the pipe, use the stock muffler and do a Y out the muffler & exit out on both sides of the tunnel. Less expensive & no additional tuning. Any thoughts on this?
sounds like a fantastic idea.... I was thinking of the same thing, but with the stock muffler you might want to consider just one exit to one side.
If you got big pockets, this muffler would be ideal for this type of configuration.
It is made by Akrapivic and is ti, dual outlets for one exit per side, nice and lite, inlet is on the left hand side, and seems to be close in dimensions to stock so it might even be quiet.
Nice muffler! I was thinking both sides just for the fact that while laying it over in deep powder you would not have any chance of plugging the exhaust regardless of what side you're on. Was thinking of stock to keep cost down.
Good point, only issue is that the muffler exits out the right hand side, so the bends wouldn't be the same, also, the bends would add about 10 inches to the length of the muffler.
Take a look at my Pepboys special exhaust bend, something in stainless with a nice mandrel bend would be about the same length but there are more options for higher quality material than what I was using.
some more pics to get you thinking
There is a ton of room under there.
Good idea on that bend. I'm sure you could find maybe a shorter muffler with a center exit. Then with a Y and bends like yours or even without the Y just using the stock muffler, and bend it to exit out the side of the tunnel right in front of that reflector. It should work & give you alot of storage space on the tunnel.
or maybe this?
dang, I should have left this topic alone...... now I got to spend some money.
You don't have access to a TIG welder do you?
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Looks perfect! Now, Just what brand / model muffler is that & will it work for the Nytro as in back pressure & all that??
It is just a random flowmaster muffler, I need to take some better measurements of the pipe, ID, OD to get one matched up better. You by chance happen to have access to a tig welder? Lots more options upon up with the right tools. I can tig weld, but I don't have a tig.......yet.
Cool, All I have is a MIG welder less the gas bottle for now. Have to get a bottle & fill it. I am curious if there will be any tuning issues using a different muffler but I can't imagine it would be much..
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