Under-Tail Exhaust: Almost Gone and Good Riddance

[shouldnthave]

Originally Posted by ScotiC

For me, it torches my ass when I'm in traffic. Added some water wetter helped a bit. At PIR there is a decibel meter that's less lenient on undertails based on the location of the meter. I prefer the lowboy look not to mention the performance advantages. I've yet to go down but I'm thinking the undertail would come out better than lowboys tho. But all said and done i like the lowboy. Blasphemy!!!!


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This last weekend I went down I and flipped my bike. The only thing that didn't get banged up was the FMF undertail.

[motociclista]

I need to cut at least ten seconds off my lap times due to improving my riding skills before I have to worry about the half a second I might gain from a different exhaust position.

Anyway, it's all personal opinion, but I like the undertail exhaust.

[Shamrock]

It's nice, that mine has been on the ground TWICE, and the exhaust is STILL untouched.

[Red October]

Originally Posted by motociclista

I need to cut at least ten seconds off my lap times due to improving my riding skills before I have to worry about the half a second I might gain from a different exhaust position.

Anyway, it's all personal opinion, but I like the undertail exhaust.

Bingo.
And hopefully if/when I get to the "I need to drop .5s", I can work on my spare tire first.

[Hogndos]

~Motorcyclist Magazine~


"I don’t mind either aspect of that, except that my Kriega backpack and Aerostich fairly reek of exhaust fumes—and will likely remain that way for days to come..."



I love the smell of [exhaust fumes] in the morning, smells like.......victory.



~Lt. Col. Kilgore

[Trip]

The vast majority of us will never be fast enough to take full advantage of the incremental evolution of the bike. But that's really not the point.

The manufacturers all have to continue to make performance improvements where they can or risk becoming irrelevent. That is the unfortunate business fact.

Truth is, most of us probably couldn't get the most out of a 10 year old bike, much less the the latest and greatest. But the manufacturers must keep pushing the ball forward because their competiton will. It's a sportbike, after all.

That's how we eventually got from leaf springs, springers, hardtails,.plungers, side valves, veritically split cases, carbs, etc., etc., to where we are today.

And If that weren't the case, we'd have never had the 675 in the first place.

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[Tucker2.0]

Agreed, which is exactly why they should offer the daytona itself as undertail and have it designed to swap easily to low-slung for those who worry about that .5 seconds or dont like the undertail anyway.

Maybe kinda like scion, design your own bike straight from the dealer!

[Serious]

Originally Posted by phiglit

I have been curious why bikes have the intake and exhaust ports facing the wrong directions, packaging wise. Why not put the exhaust headers facing the rear? I can understand heat being a problem, but having the exhaust coming out the back of the cylinders would shorten the exhaust length significantly. And putting the intake on the front would make sense if you could put the air box and plenum where the headers used to be.

It would exacerbate the heat problems coming off the headers and roasting your ass, but isn't that a problem we could get around by now with shielding and header wraps or coatings?


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Probably because of gyroscopic effect.

[Papachristou]

Originally Posted by Trip

Well, aesthetics aside, the advantages of a lower, shorter, mass-centralized exhaust are undeniable.

unless you are riding motogp, it is also undeniable that you will not notice/need the advantages.......

[bballman01]

Its not for performance or aesthetics its all about emissions, by moving the exhaust closer to the engine you can heat up the gases better to improve the efficiency of the catalysers in the exhaust.
You could argue till you're blue in the face about the performance benefits but just look at the diversity in moto gp and wsbk where there is everything from underslung to underseat.

Every design has its benefits but for production bikes the trend is to move the bulk of the exhaust under the engine to improve emissions and any other benefits it might bring is just a bonus.

Personally i think underseat exhausts work best on slim bikes like v-twin Ducatis and triple cylinder Triumphs and i think its a shame the new daytona has followed the masses because now it doesn't stand out from the pack.
So much for Triumphs slogan "Go your own way"