| Author | Message | ||
     Billybob |
I am confused some say you need a race ecm when changing a pipe,special force, others say no .From what i got from the ehhaust report on american sport bike the race ecm only matches the buellrace pipe. so what good is it? Odie says you don't need it and Kevin Drummer says you don't need it The american sport bike test was done with open airbox and k/n filters olso thanks help | ||
| Djkaplan |
If the bike in question is an M2 (you never clarified in the post, but your profile says M2, so that's what I'll assume), the only thing the ECM does is change the ignition rev limiter from a 'soft' ignition cut-out to a hard one (it won't raise the rev limit or change the ignition curve). The ECM doesn't have anything to do with fuel calibration on a carbed bike like it does on a fuel injected bike. I'd listen to Odie and Kevin who are giving good, researched and results based advice. | ||
| Al_lighton |
There is no simple answer here. Its all a matter of degree of mismatch, and how sensitive one is to things being "right". In a perfect world, the map will be perfectly matched to the intake and exhaust configuration, and the AFV will learn to a value of 100 (at sea level) no matter what RPM/throttle position the bike is cruised at. Change the intake and exhaust configuration, and the map likely doesn't match exactly. Only if you remap the ECM properly will that "perfect world" be restored. But if the changes don't cause a drastic change to the fueling curve, then the error may not be large enough to worry about. If the configuration change caused the fueling to be low by 10% at ALL RPMs/throttle positions, the AFV would go up by 10%, and the bike would run great at all RPMs, getting the 10% more fuel it needs everywhere. No ECM change would be needed. However, in my experience, that configuration doesn't exist, no pipe change I've seen is that linear. Some are closer than others to that ideal. There are generally some operational points in the closed loop learn domain that cause the AFV to learn a little lower, some places higher. This inconsistently learned AFV will cause the fueling to be richer or leaner than it should be once operated in closed loop. The race ECM has a similar response to the stock ECM in the lower RPM/throttle positions, but is decidedly richer in the upper RPM/throttle positions. If you have a pipe that is capable of making more power in those upper realms, but also has some lower RPM mismatch that doesn't cause the AFV to scale the fueling up, that additional richness in the upper realms provides additional fueling margin where you can least afford to be without it. You aren't likely to blow up a bike by running it a bit lean in the lower RPM/TP realm, because the engine has been sized thermally to deal with the heat that is generated in the upper realms. But if you run lean in the upper realms, the thermal margins just aren't there, the additional heat can be the proverbial straw. So the simple answer is that the race ECM provides fueling margin where it counts where the stock ECM doesn't. Whether or not you absolutely need that fueling margin is dependent on how badly the pipe mismatch is to begin with. | ||
| Diablobrian |
errrrr.....what Al said  You are right in that the Race ECM was designed for 1 specific pipe. Ideally since Direct Link is now in play, it is the BEST way to go if you are modifying the intake tract and/ or exhaust. However Direct Link is expensive when you include the dyno time needed to make it just right for your bike. A pre-packaged map will be able to get you close though, much closer than the stock ECM or Race ECM. The question, as I see it, is how big of a gambler are you? If you are sure that you will not have your engine go dangerously lean without changing or re-mapping then why spend the money? On the other hand, you are gambling with your motor. Can you afford to rebuild the top end (or more) if the gamble doesn't pay off? That may be over-simplifying it a bit, but I don't think it's that much of a stretch. | ||
| Xb9sbear |
So, If a guy had say, an '03XB9S and swapped out his stock exhaust for say, a Jardine Titanium, would that be an issue or not. Yes, I'd like the bike to run optimumly, but so far I've had no luck figuring out where to get a custom remap for my specific change... Robtk! a.k.a. "SpecialK" |
