[TRIIICK]

Interesting, certainly, but does it have anything to do with CAT removal?

Did you check the helmet..

 

[Diego]

:laughhard

 

[xhdskip]

No, nothing to do with cat removal,
but cool none the less, so thats got to be worth something.
I mean, just look at the originality of the parts.
A lot of work went into that red unit, and I'm pretty sure its cat free,
so I guess its an example of what you can do once you get the cat box out of the way.

 

[Natural Born Killer]

What about cutting open the Cat, removeing the guts and welding it back closed. Wouldnt cost a dime. Or does it mess up the flow? Has anyone tried it?

 

[xhdskip]

No the '05 and '06 cats were empty anyway.

 

[Natural Born Killer]

That makes no sense.

 

[Diego]

Makes perfect sense. Until about 2007 or 2008, only California's exhaust limits required the catalytic convertor. The rest of the country was more lax. The EPA has since adopted California motorcycle exhaust standards for the whole nation. (There's still a difference in fuel vapor recovery requirements, though.)

 

[dougl]

Since Triumphs in NV are the same as CA, my 2005 came with a filled cat. However, it was in a box since my dealer replaced it with the bypass.

 

[xhdskip]

I guess your emissions stuff is/ was good enough.

 

[Natural Born Killer]

Makes perfect sense. Until about 2007 or 2008, only California's exhaust limits required the catalytic convertor. The rest of the country was more lax. The EPA has since adopted California motorcycle exhaust standards for the whole nation. (There's still a difference in fuel vapor recovery requirements, though.)

But Why put an empty Cat, or anything else for that matter, on an engine.

 

[dougl]

Because they want you to shell out extra bucks for the cat bypass.

 

[Diego]

The correct answer is that something had to go there, or else they would have had to buy pipes of two different specs for the production run, so both bikes with and without converters would still work out to the correct length. The easiest thing at that time was an empty version of the cat box.

 

[Natural Born Killer]

Well, at least that makes some sense. So is the Factory tune different on an Empty Cat bike vs an operating Cat bike. Because if there is not then it makes sense that if I take the guts out of mine then the tune wouldnt be effected. And do the bikes with empty Cats have quieter mufflers than the others to compensate for the quieting effect of the Cat internals?

 

[Diego]

The back pressure was just enough different between the N boxes (the letter "N" appeared on the enclosure of those without catalyst) and the C boxes (those with) that there was a separate tune. There was no difference in the silencers, though. The system at that time was designed to comply with the noise standards without the catalyst installed. I don't expect that's necessarily true nowadays, however.

 

[odie]

I would think that the by-pass pipe would allow the air the flow much better than having to flow through a empty box compartment in the exhaust system. Less restrictive.
Any thoughts?

odie

 

[Natural Born Killer]

I gotta agree that the flow would be better with by pass pipes, but if we are only talking about a couple of Horsepower difference, then I think I will save my money for other stuff. If I cant feel the difference or see it on a time slip then what difference does it really make?
I plan to drag race my bike in stock form and then change little things at a time and see if they make more power. Maybe I will start with getting rid of the catalyst, and do some tuning, and then maybe K&N filters, Exhaust, Performance tune. etc. I wont spend to much on it though as I already have a car that will kick my bikes butt and I would rather just make it faster. Maybe this is not really the right thread for this. I think I will try to find out what these bikes will really run with an average rider on an average day............Who should I ask about that?

 

[odie]

I was thinking the exhaust by-pass would be smoother flowing through. Not really looking for HP to increase.

odie

 

[Diego]

If you're not caring about an HP increase, why worry about the smoothness of the flow?

 

[odie]

I would think that a smooth flow in the exhaust would result in a smoother ride. Although the ride is very smooth as it is stock. By replacing the box with round pipes you would lighten up the bike and get rid of some exhaust heat. It might not be enough to notice when riding.

odie

 

[Diego]

I would think that a smooth flow in the exhaust would result in a smoother ride.

Umm, you do realize that despite the "Rocket" name, it's not really jet propelled? What happens inside the exhaust system (apart from maybe a freak explosion or something) has no effect on the smoothness of the ride.

Back pressure affects affects horsepower and the tune needed to achieve it without damage to valves. But if smoothness of ride and its corollary, smoothness of power delivery, are your primary criteria, then don't mess with the exhaust system as designed and certified, and don't mess with the secondaries. These are things which impact the bike's ridability in its intended environment, the street and highway. If you plan to race, then that's a whole other ball game.