Is this the pre cat in there? (photo...)

dr_gallup said:

Devi - How do you think they install that? Looks like maybe they swage the end of the tube down after inserting the cat? Drill out the center then twist it tighter to reduce the OD & slide it out?

Click to expand...

The 2007 header is built differently. If you look close at the photo above, you can see that the collector tubing is two parts that are press rolled together, and then the end is added. The catalyst can be put in before the end is welded in place, or before the two parts are pressed and rolled together - just like on a cat for a car.

If the catalyst is fairly narrow, you can likely slide it out by unrolling from the center. If it is several inches wide (as I suspect), this will be difficult, and cutting will likely be required.

All this would be less of an issue IF they used a honeycomb-type catalyst that flows very well. With a ceramic coating on the piping, and a well designed catalyst, a 500 rwhp car loses less than 10 hp. That is a negligible amount of power - especially for a vehicle that burns VERY clean.

I am all about clean emissions WITH improved performance, but it will be a while until the OEMs figure out that a well designed catalyst and exhaust system can actually benefit them and their sales. Right now, each only does what is mandatory to get them but each years regulations.

If Triumph were to redesign the exhaust and spend a couple of dollars more on the exhaust, they could tune the bikes for greater performance and SELL MORE BIKES. This would greatly offset the additional costs, and the bikes would burn even cleaner than they currently do. They could work WITH the aftermarket and enthusiasts instead of changing the parts every year or two, and we all benefit. Sorry, RANT OVER.

The big restriction in the exhaust is the stock silencers. So the midpipe on the later bikes is likely not going to change this much - if at all.

I am under the impression that the 4 hp gain for the 2007 bikes is from the Arrow 3-1 system - not on the standard bike (this may easily be incorrect). The last dyno charts I saw for a 2007 model in a magazine showed the same power as the 2005-2006 models. But it is possible that even with the catalyst in the midpipe, the improved tuning (not much) of the later ECU may give the added 4 PS.

Until we see a member dyno his 2007 model we will likely not be sure about this. If you compare the early and late 1050 tunes, they are nearly the same, so I would expect the same peak output.

I do wish Triumph would change to the honeycomb catalysts though, we could do a lot with a good silencer on the stock bike. The stock silencers get HOT, and stay that way for a long time - compared to other silencers.