| Author | Message | ||
     Saratoga |
This is old news I'm sure, but anyone considering being cheap and zip-tying the exhaust valve open on their 12 can save themselves the trouble. It sounds like crap for one thing, and actually falls flat from idle through 3500. About all it does is make the bike obnoxiously louder. Needless to say, I'll be taking the airbox cover off and re-installing said cable into the actuator again tonight. | ||
| 1_mike |
One major thing to consider...did you give the engine more fuel? If the system is free'r flowing out...it must be compensated for on the other side...more fuel. I'd be willing to bet...if you look at the fuel (and maybe the timing) maps...when the exh. valve opens in the muffler...more fuel is injected into the engine to properly fuel the free'r flowing system. The human's gotta work smarter than the mechanical parts. Mike | ||
| Andymnelson |
"About all it does is make the bike obnoxiously louder." lol, you would not like my X1 with Force exhaust system. :-p | ||
| Zatco81 |
BTW...When are we gonna see the X1 Andy? | ||
| Xl_cheese |
One major thing to consider...did you give the engine more fuel? If the system is free'r flowing out...it must be compensated for on the other side...more fuel. O2 sensor will automagically give the bike more fuel if it needs it. | ||
| Xl_cheese |
How do you know it falls flat during the lower rpms? Have you done any real measurments? | ||
| Andymnelson |
"BTW...When are we gonna see the X1 Andy?" I've been debating. :-p I want to post up pics, but I have some big ideas for a new front end, so I've been waiting.  I think I'll post up a thread in the old school board showing the bike and my thoughts for mods... I can't wait for the winter tear down of the XB tho. I have a friend with a HUGE powdercoating facility. Pretty sure the XB will emerge from the winter with a white frame, swingarm, wheels, triple clamps, etc. Also white plastics with some tasteful and simple blue and purple graphics (it's my my girlfriend after all), and probably a blue powdercoated header, ala X1. | ||
| Saratoga |
SOTP meter. "Falls flat" may be the wrong description. It accelerated better at lower rpms with the cable attached to the actuator. | ||
| Pkforbes87 |
"O2 sensor will automagically give the bike more fuel if it needs it." The O2 sensor, and the AFV that it sends to the ECM are only designed to compensate across the entire fuel map at once. It works for changes in your riding environment like temperature, altitude, and humidity but the system isn't designed to make adjustments to specific parts of the fuel map. If your fuel maps are designed for an exhaust that opens at XXXX rpm, then it's going be lean up to that point, then get richer as you pass XXXX rpm. These bikes don't have mass airflow sensors, which is what would be required for the ECM to even have a clue as to how freeflowing your exhaust/intake setup is. | ||
| Jaimec |
When the XB's first came out I read about them in a Canadian Sportbike magazine (I was in Nova Scotia and saw it on the newsstand so I grabbed it). They wrote about how the exhaust valve kept the exhaust nice a quiet up to a certain rpm (where the noise levels are checked for compliance) and then opens it up at higher rpm (where the noise levels are NOT checked). The interviewer specifically ASKED the engineer what would prevent the end user from pinning the valve open ALL the time. His response was "Nothing, but then you'd have a HUGE hole in the powerband if you did that." The purpose of the valve is NOT just to pass sound checks. It is to smooth out the powerband between low rpm/low throttle and high rpm/high throttle. | ||
| Xl_cheese |
The O2 sensor, and the AFV that it sends to the ECM are only designed to compensate across the entire fuel map at once. It works for changes in your riding environment like temperature, altitude, and humidity but the system isn't designed to make adjustments to specific parts of the fuel map. In the Closed Loop region of the fuel maps the fuel is adjusted on the fly by the EGO. corr. percentage and not the AFV. The EGO. corr is calculated from O2 sensor voltage. AFV is calculated from some sort of running average of the O2 sensor. The AFV is only used in Open loop. In the specific range that the original poster is refering to Closed loop is working thus the O2 sensor will make adjustments. If you want to see all this work then plug ecmspy into your bike and let it idle until it gets warm and switches over the CL. It'll idle with the AFV multiplier when warming up plus the cold temp enrichment. Then when it warms up enough you'll see ecmspy switch over to CL and you'll notice a change in the idle. | ||
| Saratoga |
Re-mapping aside, it runs one hell of a lot better with the valve functioning now. The loud part didn't bother me, it literally sounded like ka-kah. Definitely not that deep rumble that a special ops or drummer would have, almost tinny and cheap sounding. All is back to stock until I'm feeling impulsive and lay out for the real thing. | ||
| Growl |
You don't need to even consider wiring up the exhaust actuator valve (which degrades mid rpm power and makes starting a bit harder) because there is a better option. The ECM actually has an alternate program built in which allows the actuator to operate differently... and there are adjustments available to tailor how it works. I have a friend with ECM Spy and he helped me follow this advice from BadWeb member Sekaliagai: http://www.badweatherbikers.com/buell/messages/142 838/375761.html I programmed my actuator to be closed below 750 rpm (to preserve easy starting) open from idle to 3200 rpm (which makes the bike sound better - growls instead of the loose marbles sound) and it runs great! Then it closes above 3200 rpm to preserve the mid range rush! It still opens when throttle is wide open... all in all an inexpensive and worthwhile improvement. My bike has a soul satisfying tone but is not going to bother anyone. As with any exhaust system change - remapping the fuel tables really makes this work... improved low rpm running, more power at high rpms and an average of 48-50 mpg. By the way, my experience is with a 2006 Uly. |
