Adventure Bike Rider Forum

catcitrus wrote:Now the new T7 is being launched here with that extra catalyst in the headers to meet Euro5 I'm assuming that the "old" model will continue in the US etc with the original system?--anyone know?--I know it happens with other Yamaha models like the WR250R which was sold without even a lambda sensor in the US.

Not sure
USA & NA bikes are made in Japan
Oz and NZ bikes are made in France like EU bikes and I seem to recall the Oz bikes have EU spec headers with the extra emissions add on, despite it not being needed in Oz for compliance

Thanks for that--I'll see if I can ask our NA friends on ADV.

I've been watching Pirate Racings youtube channel, he's been doing a bit of testing on T7 exhausts. It looks like there is no point in changing the tail pipe for performance gains as the best only got a tiny extra bit of power and no overall gain.
I can't understand (or speak) German so I don't know the extent of his testing or if he had a go at optimising the fueling to suit each change but it's worth having a look.

Steve

bowber wrote: ↑Tue Mar 16, 2021 2:19 pm I've been watching Pirate Racings youtube channel, he's been doing a bit of testing on T7 exhausts. It looks like there is no point in changing the tail pipe for performance gains as the best only got a tiny extra bit of power and no overall gain.
I can't understand (or speak) German so I don't know the extent of his testing or if he had a go at optimising the fueling to suit each change but it's worth having a look.

Steve

Basic physics--by the time the gas has worked its way down to the muffler, and possibly been through a catalyst as well, cooled down to the extent that you could get away with half the pipe diameter and still maintain flow velocity, any change to restriction at the ass end will have virtually no effect on breathing/backpressure --except at peak revs and throttle--and who rides a T7 there ? Just because it sounds louder doesn't mean its doing any good--quite the opposite--cam profiles and timing coupled with backpressure are designed to give optimum efficiency throughout most of the operating range. The best you can hope for is a weight saving--any performance gain will largely be a placebo effect. However, a lot of people make a lot of money for systems that are simply straight through absorption designs that you could make yourself with a basic tube, end plates, some perf tube and wadding!

I've changed my silencer and feel no performance gain whatsoever but I have shaved about 2.5kg of weight and it looks soooooooooooooo much better.

boboneleg wrote:I've changed my silencer and feel no performance gain whatsoever but I have shaved about 2.5kg of weight and it looks soooooooooooooo much better.

Which exhaust?

not sure on mine i put a dominator can on and a akro sticker ....i did think it gave a little loft in throttle responce and sounded great ...obviously it was the akro sticker that made the difference ...mute point now as ive sold the bike to a freind ....but for what its worth i thought the exhaust was good value

photo upload site

boboneleg wrote: ↑Tue Mar 16, 2021 8:21 pm I've changed my silencer and feel no performance gain whatsoever but I have shaved about 2.5kg of weight and it looks soooooooooooooo much better.

These days that's about the only reason I can think of to change the silencer.

Steve

bowber wrote: ↑Tue Mar 16, 2021 10:22 pm

boboneleg wrote: ↑Tue Mar 16, 2021 8:21 pm I've changed my silencer and feel no performance gain whatsoever but I have shaved about 2.5kg of weight and it looks soooooooooooooo much better.

These days that's about the only reason I can think of to change the silencer.

Steve

main reason tbo steve was to keep the marks off the o/e when it went over ,,,,wouldnt put owt expensive on it ..still maintain it was a bit more sprightly after it went on ........who knows

minkyhead wrote:not sure on mine i put a dominator can on and a akro sticker ....i did think it gave a little loft in throttle responce and sounded great ...obviously it was the akro sticker that made the difference ...mute point now as ive sold the bike to a freind ....but for what its worth i thought the exhaust was good value

photo upload site

You have sold the T700, Steve?

Not to your liking ?