Tunnel Open or Closed?

[Ted Jannetty]

What is the consensis, are you guys closing or leaving the tunnel open?

 

[sniperviper]

I'm closing. Really cant see any reason to leave it open. Have never heard about exhaust cooling other than on all yamaha 4strokes snowmobiles..

 

[go200mph]

Has anyone actually closed it in and used it yet for any length of time.

 

[EsonPZ]

I have closed mine. Rode 250 km (155 miles)last week and no problems.

Pictures here: www.ty4stroke.com/viewtopic.php?t=36465&start=15

 

[Phazed]

I plan on closing mine, eventually.

 

[grapeape]

closing it off costs hp...

 

[EsonPZ]

closing it off costs hp...

I cant see why it would loose hp. Facts please.

 

[Mars]

Hotter exhaust = more power.

You have to keep the heat in the pipes to make power.

 

[grapeape]

I personally asked the Yamaha rep why is there a hole. Answer was it made 4 more hp with the hole thatn without. Also if you want you can run regular gas , but hp will drop as well, as the timing will retard itsself.

 

[EsonPZ]

Ok, but how would they know that it gains 4 hp with the hole open. I mean there is no snow hitting that pipe when running it in the dyno.

 

[Superman]

I wouldn't do it. I can just see something melting or worse.

 

[Jack_Shaft]

Ok, but how would they know that it gains 4 hp with the hole open. I mean there is no snow hitting that pipe when running it in the dyno.

HA! Best post in this thread. Captain Common Sense Prevails!

Good point. I would certainly close mine off if I had one of these sleds, too much ice and crap all over the running boards for my taste.

 

[twest]

One member at Snowest.com ,close it, his comment "it melted everything " I don't see how but that was his comment,so if condition are right you can melt the flares or worst, I am installing the Factory Aluminum flares.

 

[sniperviper]

If thats right it must be the stock pipe who gets so warm. I'v talked to Marklund at MC-X because they close this hole completely on their turbokit and he told me that they have tested it out and there was no problem at all doing this.

 

[Red2003]

I don't see why it should melt anything down. Look how close the exhaust runs to the number plate and seat on a 450F and it doesn't melt down in the Summer at 90 degrees. If that muffler runs that hot, you'd gain 15 HP by strait piping the thing!