I would agree if my intention was to build another 100+ hp sportster, but it isn't, so I don't. I want good torque in the range I usually ride in, and that's 2.5-4.5k. Past that, I don't care. It looks like Cobra selected attributes to make a mid-range performer, and there it is. Personally, if I could, I'd go a few inches longer and maybe taper the collector, or maybe use a short crossover before the collector to pull the torque curve up a bit in the low end. Other than that, it rides nice, and I'll play with it as-is for a while.

 

Sounds like you found the pipe that serves the specific purpose you are after. If you decide to install the TTI please share another dyno chart. I'm curious to know if it helps bring curve up where you want it.

As for me I'm after 100+ HP and am looking for the right pipe to have ready for the Hammer 1275 120+ HP kit coming in the future. So far the Rush slip-on's are what im looking at based off of the dyno results on Hammer's website and since the Patriot Defender went away. Had one on my 48 and liked it but it broke in a few places in just over a year and always scraped on right hand turns.

 

looks like Frankzilla's system is pretty well optimized with the 1250 setup and whichever Bassani 2-1 system he used. Looks like Bassani RR2 B1 Mega is made for handling exhaust flow for big power while preserving the low end.

 

Ive got a set of chrome ones sitting above my garage, ill sell em cheap..

 

I didn't realize that was a quoted post and the chart and set up actually belonged to Frankzilla. I looked for that pipe but can't find it for the Roadster. I really liked the Road Rage 3 but after seeing the results on the XL Forums I would rather not blow 800 bucks for one and try to find a better performing pipe. Looks like the performance is similar to the Diablo.
http://xlforum.net/vbportal/forums/s....php?t=2012160

 

RR3 does appear similar to the Diablo, except for a few inches longer on the head pipes. But muffler volume is small.

fitment guide says this guy will fit the roadster:
https://www.jpcycles.com/product/834-357

 

I guess I missed that by searching for the RR Mega Power. This one looks pretty much Identical.

 

I bet the reversion seen in the RR3 and Diablo could be mitigated somewhat with a TTI.

 

Yeah most likely but if I'm gonna spend 600-800 bucks on a pipe I'm gonna be really hesitant to be drilling into it to install a TTI in it. I want to buy a pipe that's gonna perform well by design that doesn't need to be modified in any way to make it perform better.

 

you may want to see what shakes out in the near future for the sportster line. the bobcat, rr (not just the rr3 everyone obsesses over...because?), and the stock configuration (bwana1) seem to work just fine.