Excel under tunnel exhaust on CPR trail machine

[snowmaaan]

Anyone have any experience with this setup? I have heard they are known to build to much pressure in this setup...but didnt know. Anyone?

Thanks!

 

[Fergie]

I have the cpr set up for around 12psi with stacked gaskets with excell & powderlites header & LOVE it. this is on an 07 attak gt

 

[snowmaaan]

So the exhaust exits under the tunnel like a mountain exhaust would? If yes, any trouble with too much backpressure as result of track spinning a million miles per hour?

Thanks!

 

[millstreet]

There've been a couple (heated ) threads about dumping exhaust from a turbo'd sled into the turbulence created by the track. In a nutshell, some experts kinda decided it costs some power at some levels, but the mountain guys were willing to give up a couple HP for the weight savings

Feel free to correct me if I'm remembering this wrong.

If you do a search, you may be able to find it - (nothing specific about the Excell product though) - almost as interesting as the air intake behind the windshield saga


Anyhow, I'm kinda curious about the effect on a SC sled (as opposed to a turbo), and if anyone has the Excell Mountain Lite dump - in specific - how loud is it? There does not appear to be a whole lot of muffler

 

[millstreet]

I found 1, but I think there's more

http://www.ty4stroke.com/viewtopic.php? ... highlight=

 

[aja636]

I think that the mountain lite exhaust would be back far enough not to get effected by the air generated from the track.

The problem with tunnel dump exhaust is they where dropping it at the front of the tunnel in a confined place and when riding all the air and snow being thrown and jamming up there the exhaust was building some back pressure and thats not good for turbo or S/C sleds.

The mountain lite runs back through the tunnel to where the track turns down right? I wouldn't see why that would be an issue

Maybe ted or dave could chime in on this.

 

[millstreet]

Excell Mountain Lite pictures at

http://www.excellmotorsports.com/

then click on RX1 or Apex under performance on left

 

[aja636]

I have the cpr set up for around 12psi with stacked gaskets with excell & powderlites header & LOVE it. this is on an 07 attak gt

Where you at the shoot out we had up in Old forge last year??
If not you should be there this year.

aj

 

[yamaha_junky626]

excell exhaust

hey snowmann i put excell mountain light exhaust on that attak i bought from you. runs just fine with it, it is on the loud side especially behind it. it exits far enough back that backpressure shouldn't be an issue. i have the stage one supercharger running max boost so its like 10 or 12 lbs

 

[millstreet]

Re: excell exhaust

hey snowmann i put excell mountain light exhaust on that attak i bought from you. runs just fine with it, it is on the loud side especially behind it. it exits far enough back that backpressure shouldn't be an issue. i have the stage one supercharger running max boost so its like 10 or 12 lbs

Did it make any difference in your A/F #s?

How loud? Like obnoxious loud?

Thanks!

 

[snowmaaan]

Thanks for all the info...looking at a CPR sled with one...will probably swap back to stock exhaust to avoid to much noise!

You guys are great!

 

[yamaha_junky626]

exell exhaust

noise level is comparable to a two stroke with a can on it. i think when riding it though it might be quieter just because the exhaust is exiting behind you and not in front of you. i can't remember if it changed air fuel ratios or not.

 

[millstreet]

Thanks

 

[woodsrider]

FYI, I was told by a Yamaha R&D guy that Yamaha had tested a tunnel dump on the 4stokes when they were in development but decided not to go that route because if you let the sled idle long enough the track could catch fire. They were dumping at the front of the tunnel, for liability issues they nixed the tunnel dump. I've run a tunnel dump for yrs with no problem I guess it takes some common sense.

 

[Fergie]

I have the cpr set up for around 12psi with stacked gaskets with excell & powderlites header & LOVE it. this is on an 07 attak gt

Where you at the shoot out we had up in Old forge last year??
If not you should be there this year.

aj

yes i met you & your dad at slickers & took the ride but did not race. do you have any dates yet for this year? (i guess we have to wait for the lake to freeze) & sorry for the missunderstanding mine does not exit under the tunnel.