Subthrottlesare exactly what bg has stated. You may hear the term flies, butterfly plates, subthrottles, secondaries, or plain old, plates. It all means the same thing. AS you ride the bike, you accelerate at a brisk pace, you can fell that slow, linear climb up the rpm scale. The subs follow more the rpm rather than gear changes. The plate has no idea how fast you are going, being if the GPS or the speed sensor were not attached as in function, the engine could care less. RPM and the ECU work to run any fuel metering needed.
You will hear people talk about "Lean" as if the subs are completely gone, [removed/locked], then all of a sudden there is a fear that because something has been altered, more air can get in and cause havoc? There is a part in the factory shop manual that states it is safe to ride the bike if the sub-system ever failed during service. What the book mentions is that they will raise the subthrottles for you and you may now proceed along without any other modifications needed. Well, say there is a code present and now your sub is on the blink and you need to see the dealer for repair. Where is the lean if the factory says to proceed once they themselves control the subthrottles to lock open? There is no footnote given as a caution that you should not ride the bike {as the subs open to code]. No, it says you are safe to continue riding. Ask that person who told you where that lean came from?
What some people miss with fuel injection is that the crank and air know when the air is going to open the throttle real quick or say... How can the bike engine go lean if you whip the throttle up at idle in neutral? How can you rev your car engine in park and there is no lean when you WOT the throttle. Does it not move so quick you better back off or it will hit the rev limiter or hit redline just like that and ask yourself where is the lean on a fast open throttle from idle?
There are guys that had their bikes tuned on a dyno with the flies out and found no lean or fuel change by altering the fly opening. The air speed is the event. In other words, it is like you WOT the throttle at idle and she snaps to attention. Now, where is the lag at the throttle? So, do you now see that the manual shows it is safe to ride, being that all that occurred was a faster ingest of air as in time? The time is how much faster is the throttle with the '08 and later year; is if the sub was not even present does the '08 whip up the throttle? Do you see the lean is not too lean is now try it without an air cleaner and you will feel the nose dive being it needs to match the speed of air or say bring more fuel than air so it can fill the chamber soon with fuel than the air is where the...
Fuel Trim... comes in. This is where one runs for the Pc unit or a fuel trim device thinking they need to richen the bike for fear of a lean condition caused by the fly mod? I have to tell you that I am very lean if you want to call a gutted exhaust moving faster air; removing a screen of a stock air cleaner that once restricted the air flow is now removed. I have hammered my bike on the bottom end where lean should count. I have zero lag on a fast open throttle. When I removed my air cleaner to ran open ram, yes, I did feel a slight lag and then it took off. I then reinstalled the air cleaner and the bike reverted back to a crisp throttle, no lag, no excessive popping, nothing out of the ordinary where the throttle could not handle the new flow from the screen-less air cleaner, the open exhaust flow, and the open subthrottle shaft locked open in place.
Guess WATT? I do not need a piggy helper. Recently, I took off at high speed, being the officer and I only know what kind of speed I was doing. So, you know I am a high speed hammering kind of rider if you notice how many incidents I have had with the 14. The bike runs like a clock. Not one hint of engine damage from the oil changes, to pulling spark plugs and looking down the cylinders with a scope.
Lean would mean: Piston knocking from excessive heat. Piston holing as if the bike transformed into a 2-Stroke, which either leaned out or detonated itself to death. The water temperature would be out of safe range and boil over. None of this has occurred with the modifications I have followed along with your mods.
If you want more power, then you use more TNT. So, if say we start to add a fuel trim to the peak tune of the 14; this will soften the peak power the bike is in now. You will have more power, but it will be toward the upper power band where it will help. If you fluff the bottom with more fuel, you will lose a slight bit of peak low end boost. That means you will waste all that fuel is where are you going? Are you racing or street riding?
I have set this bike in many stages of tune. I've run with and without a fuel trim. Fuel trim is nice if you work more upper rpm type performance. But if you think because you read others discuss how you can hurt the bike, make them read the FSM; point out where it says you need to piggy if the flies happen to a coded locked position. Guaranteed, you will loose the ragged edge this bike is tuned to. That is why I do not run extra fuel to wash out the crisp response the bike can make all stock. It basically remains stock and has a few mods to help increase a slight tweak to the air flow.
No lean. No piggy. No BS!
Tormenting the motorcycling community one post at a time
