I just bought an f2 which came with an D&D shorty exhaust. What exactly is the purpose of using a shorty and does it increase performance? Coming from the dirt world mainly running smokers I would think it would decrease it due to back pressure

 

If the carbs were re-tuned, it can work out. How does the bike respond?
Any dead-spots? Or does it pull smoothly through the power-band?

IMO, most of the shorty's, are a bling-thing. Louder, 'tougher' looking, etc.

Of course, I believe more in the "Stealth, observe all around me" vs "I'm so loud,
of course, you see me." I swapped the carbon D&D that came on the bike,
for a stock Smokin' Joe can. So take my post with a 'grain of salt'.

Ern

 

as stated above, people do it more for looks/sound. i have a shortened jardine muffler on my f3 right now, the only reason i shortened it is because i hated how it stuck out past the rear tire, made it a little louder, but i didnt really care about that.

 

madhattr is right about retuning the carbs to the shorter exhaust..
my experience is although louder and (again i agree with madhattr i enjoy a lower profile exsistence).. there def is more horsepower at the rear tire!!! or again take my opinion with a grain of salt too!! maybe it just seems faster too me.. like WoW: this thing is screeming, it goes so fast..

and my disclaimer is: i have two identicle bikes. one has a unknown shorty w/carbs that were tuned to it and the other bike has a long d/d pipe and a jet kit.
and you guessed it! the bike with the shorty feels more powerful/torky.. come to think of it.. im going check and see if they both have the same amount of teeth on the sprockets.. brb..
i just was able to check the back ones and their same at 43 teeth and again i feel like the bike with the shorter pipe is def faster... but def louder as well..

 

+1 on bling, it looks damn good but yes it absolutely changes the backpressure characteristics. The 1st pipe I chopped to a shorty was a carbon micron (no I am not $$rich$$ it hurt to do it) and once I had it done I bolted it back on, took her out and discovered I had a very "fluffy" throttle, no real power down low but everything in the upper revs seemed better. This is a 96' yzf750sp which prior to the pipe mod would happily get the front end in the air with little effort. Now she felt sick so after pondering the effects of the cut pipe I decided to try plugging the exit of the pipe a bit and see if it was better or worse. I stuck a large handle plastic screwdriver in the exit of the pipe and fired her up. The throttle was powerful and immediate, no fluffiness at all so a good guess for me lol. It seemed I needed to slow the flow of air a bit for the pipe to work like it should. So I went and got some stainless steel window screen and started with one layer at the rear exit and with the bike running kept adding layers until she felt right at the throttle. It was four 3"x3" squares of stainless window screen so I put two at the head of the pipe in between the mid pipe and shorty. The other two went between the pipes baffle and exhaust cap. This was 5 yrs ago now, still works perfect and when done right with the stainless mesh it looks like the pipe has a spark arrestor in it! And for some reason it makes the bike look even more badass lol