All right. I have come to this site several times seeking knowledge on my exhaust. I have Read alot of good info. So i made an account to tell you my story. I own a 05 XL1200 (got to love carbs). Well i wanted to put drag pipes on my bike but heard they were a bad idea. With lots of reserch about touque cones and lollie pops. I was going to buy a set of drag pipes for 200 sum odd dollars. Being cheap as i usualy am i wanted to utilize my se2 exhaust that is all ready on the bike. I took out the baffles and went for a ride. Awful sounding(sounded like one of thoes dropped cars that sound like tin cans). But to my surpize the bike was more responsive. I thought i was going to loose my low to mid touque but it was all their, with no back fire at all to my surprize, I bought the bike with se2, stage 2 jet, ignition mod, and after market air (i can post the specs on that equipment if you want). So what i did was took my baffles out and brought them to the shop. The factory exhaust size is 1 7/8 id. Same as my baffles. Earlier iin the day i went down to auto zone and bought some 1 3/4 exhaust pipe (18 inch in lenght) six dollars a peice. I cut out the flapper in my baffle that scoops the air and sends it threw the packing. So with that gone i slipped the 1 3/4 exhaust pipe inside the baffle which made them stait pipes. Now with the exhuast being 1 7/8 from the engine gageing down to 1 3/4 inside my se2. It in my oppionion makes some back pressure. The best thing is that my cross over tube is still 100 persent funcional. There is no tunning need for my bike because befor she was running a tad rich, and with all my after market goodies all ready installed the bike seems to be ALOT more happy. There is no back fire and she screams on the high way... Now it does not have that 100 percent drag pipe sound (never have owned drag pipes) but for 12 buck and alittle time i am satisfied. I will eventualy put real drags on the bike but for this temporary solution i am Very happpy. Hope this helps someone in the same mind set as me......Happy riding (i took pictures of the process but i dont know how to post them)

 

What is holding the 1 3/4 pipes in place?

 

There is a small indent at the end of the baffle that holds the end cap on that was already their. So when i inserted the pipe it naturaly stopped befor it fell out the back. I am currently waiting to get the pipe that i inserted welded to the baffle (to make it 100 persent air tight) but the inserted pipe is not going anywere in the mean time.

 

What you have now and the reason you aren't experiencing the expected loss of torque associated with drag pipes in the low to mid range, is explained by the fact that you maintained the crossover pipe which is controlling exhaust reversion.

Here is a simplified explanation;

A Cross Over on a Motorcycle - They usually only have 2 Cylinders.

It is actually a little more technical but I’ll try to keep it simple.

In the case of 4 stroke motorcycle engines, the reason for a cross over is this...

After a cylinder fires and the piston cycles “up” - exhausts gas vents through the Exhaust valves, along with the remainder of the “explosion”, exiting the cylinder into the exhaust system.

This explosion creates 2 pulse waves… a Sonic Pulse - and a Thermal Pulse.

When the faster Sonic Pulse leaves the exhaust it has created a vacuum in the pipe behind it, which air pressure will enter the pipe to fill the vacuum. This air will collide with the Thermal Pulse and cause it to reverse. The timing of this event causes exhausted gases to be returned to the cylinder while the exhaust valve is still open therein not allowing all the spent gas to escape and also polluting the environment for your next stroke cycle with fresh air/fuel mix.

This “Event” is call Reversion and seriously degrades performance and lifetime of valves and cylinder heads.

The Cylinders fire opposite of each other – or nearly so on a Harley. So when One side is firing, the other side is idle. Having the cross over pipe allows the pulses to dissipate back and forth between the tubes instead of - or before exiting the exhaust and therein greatly diminishing the effects of reversion and so improve performance and engine life.

Yes - you see a lot of bikes with duels and no cross over. These are usually "Tuned Pipes".. meaning their length and size are tuned to work with the S/T Pulse in such a way that reversion can not return to the engine before the exhaust cycle has ended.

 

Any rattle with it just sitting there? So just to clarify 1 3/4 pipes shoved through to the end of the baffle which stopped the pipe as there is a detent that stops it, right.

 

How did you punch out the end cap,did you try it with just the end cap removed?

 

my baffles on the se2 are the old style. The flapper niside that deverts my air into the packing inthe baffle was removed with an air tool grinder with a metel cutting blade. When i installed the pipe it was in the direction o the flow of the air. (not inserted from the end of the exhaust, but installed at the beginning of the slip on back) The baffle was out wen i installed it. i was snug and required a few taps from my hammer to get it all the way down to the tabs that i was talking about. i have two pictures on my phone that i can send to you over a text (i dont know how to put them on this post) the pictures should help

 

Thanks cHarly you info is useful. I did not know that and i will keep that in mind when shopping for a set of drags

Sancheese try googling (images)sc2 baffles and see the differance between the two. Mine are from 2005. i think you are talking aout the new style baffles

 

Stevo my se are old ones and the cap was about half way down I knocked them out the other day , was there a noise diffedence between running it straight thru the baffle and then when gou had the straighf pipe thu ?

 

I pulled the baffle compleatly out and went for a ride and it sounded alot loader but it had an aweful tin can sound. From there i cut out the flappers and reinstalled them with the pipe strait threw. I never did install the baffle back in with the flapper cut out. Befor i started this whole prodject i stuck a lond peice of re bar inside the slip ons (while connected to the bike) and opened that flapper up some. the bigger the hole the loader it got but i didnt like the sound (had that tin can sound) thats why i went with the pipe threw to create smother air flow.