|Posted on Wednesday, March 31, 2021 - 10:56 am: ||
And now a big request, can anyone still have a fuel card under Barker's exhaust ??? Very necessary)))
|Posted on Thursday, April 01, 2021 - 08:44 am: ||
Nope doesn't look like mine.
|Posted on Friday, April 02, 2021 - 11:34 am: ||
It looks very well made! Nice job.
|Posted on Saturday, April 03, 2021 - 12:47 am: ||
What's inside of your "can" ?
P.s. - Do you have a Furano ?
|Posted on Thursday, April 08, 2021 - 01:00 am: ||
Noticed that in all of the discussion about ideal scavenging/resonance, nobody mentioned that it seems every newer performance bike I've seen for years has servo-actuated butterfly in the exhaust. Certainly for a number of reasons, but it must be such an advantage to engineers to be able to add that to the tuning matrix, dial it in for every variable such as temps, throttle opening, etc.
And of course R1's (and probably others) have for decades employed an longer intake tract that pops up and down instantaneously at a given RPM, varying the intake length (stack). Yes, all tradeoffs, and one of these days if electrics don't take over, they should all have some sort of totally variable valves (i.e. pneumatic) which would eliminate the need for throttle bodies and be infinitely tunable. So we can have all that power we seek since modern bikes are only making 200 whp at the moment.
And if you like nifty, that is simple and elegant engineering solutions; I once met a guy who suggested that a very, very simple way to vary valve timing would be to shift the pulleys on the timing belt/chains. If both tensioner pulleys were attached to a simple slider (perpendicular to the top/bottom pulleys) it could easily advance/retard the timing. Ideally each camp could be adjusted independently which could easily be accomplished as well utilizing idler pulley between cams, or some such mechanism.
Complicated? Certainly, but not nearly as much as a Vtech or any of the other variable systems I've seen (isn't BMW and Ducati all variable timing now?) utilizing oil pressures, variable-clocking cam gears, etc. A stepper motor adjusting a lateral slider holding the idler pulley is much easier than any of those.
And while you-all may have seen my previous post regarding the poor quality, then customer service at Barker's; I do understand that cone to be the key to their exhaust, and once spoke at length with the engineer who designed our bikes, and he stated that Barker's was one of the better exhausts available. I don't see how that dyno shootout could be flawed, but I have a hard time believing that when I added my Race Map it added that much power (and have spoken with others who claimed the race maps don't add much power). And for all the talk of poor fueling in the 1125, I won't say it's all that poor.
That exhaust looks very nice, but to my ignorant eye not only is the cone shape critical, but how it terminates (abruptly vs coning back to the larger diameter), and inside the Barkers, right where the cone meets the can, is a very thin metal disk that itself is a slight cone shape with a smaller hole in it. So the cone terminates into an almost flat metal disk with a smallish hole in it, before the gasses enter the muffler. To my knowledge Barker's claims this is the key to their tuning, which seems reasonable, and every dimension is probably fairly critical/would presumably change the tune according to all the variables Stevel enumerated. These things seem funny; in a way very complicated, yet also some things are very crude. And there is more than one way to accomplish the same end, and nothing but tradeoffs in any application. If there is one thing I understand about engineering, in most applications it isn't done academically, its all trial and