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Discussion Starter #1
I got a call from Fuel Moto USA today who is using my bike for R&D. They were just getting ready to make some baseline pulls with my bike. I'm like a little kid in a candy store and can't wait to be able to tell you guys my little guy is making over 30 HP lol. The owner said he will email me all dyno sheets as they go along. I'm sure it's going to be a while because they are building a pipe, porting the head, shaving the head, possibly making cams, heavier valve springs and loads of tuning.
 

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What about a big bore with all the head work? or is that being greedy :D
 

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Discussion Starter #4
Talked to jamie at Fuel moto today. Dyno jet sent them a fuel controller that is not avaliable to the public yet to tune my bike with. I can tell you guys right now that the bike stock runs lean!! i've seen some people posting that the bike runs rich but it is the oppisate. I believe it the AFR was somewhere in the high 14's. He will call me this week and see what they get out of it in stock form.
 

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Nice one, I've always felt it was running lean, and the most effective cheap performance mod was to change the fueling.

I'll be interested in fuel controllers that a tuned for the stock pipe.
 

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Running lean is probably what Honda designed into this bike.
The original intent was fuel economy, even though it looks "sporty".
 

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Lean can mean more power, problem is it also means more heat which can be damaging. So if you do a controlled lean burn (like I've seen this engine advertised as) you can gain power and MPG, I wouldn't say that it was losing power from running lean myself.

Then again like I said it means more heat so if it's not properly letting the heat escape out the exhaust and cooling system then enriching the mixture could help, however I'll just wait to see what happens.
 

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Discussion Starter #10
I guess the problem they are having with tuning it is the bike is in closed loop until WOT. Alot of bikes when tuning you disconnect the O2 sensor and run a simulator to keep the light off and you tune it from being in open loop. This bike if you do that it go's into limp mode. Another thing he mentioned was they put the sensor right out of the head. Why is this? who knows but most bikes run them down the head or mid pipe. We will see what happens, they are one of the best tuners out there so I know they will get it right. DynoJet is bugging them to get it handled so they can start selling these units to the general public.
 

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Closed Loop Feedback for dummies

Closed loop, as applied to engine control, means as control changes are made, some variable is measured to determine whether the setpoint is reached, or whether more or less adjustment is required.

For instance, in a typical fuel-injected vehicle, when you first start a cold engine, lots of fuel is required to keep it running until it warms up. The computer simply dumps a predetermined amount of fuel governed only by engine speed, throttle position, and engine temperature. There is no point in trying to fine tune the fuel delivered at this point, since the mixture needs to be soggy rich just to keep the engine running. This is called open-loop control.

Once the engine has reached operating temperature, the computer switches to 'closed-loop' control. This means the computer receives feedback from an oxygen sensor as to whether the mixture is too lean or too rich, then it makes adjustments, then checks the sensor again, then makes adjustments, and on and on in an infinite loop.

To understand the principle, imagine if you were to close your eyes and type words on your computer keyboard. If you are a good typist, the words are probably correct, but you have no way to know if you made a mistake. That's open loop control. There's no feedback as to whether the desired result was obtained, you simply have to assume that the correct words are there. Now open your eyes. if you mis-typed a word, you now have the feedback that you messed up, and you can type in a correction. That's closed-loop, from your fingers, to the keyboard, to the screen, to your eyes, which control the fingers. See the loop?
 

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Discussion Starter #13
Closed Loop Feedback for dummies

Closed loop, as applied to engine control, means as control changes are made, some variable is measured to determine whether the setpoint is reached, or whether more or less adjustment is required.

For instance, in a typical fuel-injected vehicle, when you first start a cold engine, lots of fuel is required to keep it running until it warms up. The computer simply dumps a predetermined amount of fuel governed only by engine speed, throttle position, and engine temperature. There is no point in trying to fine tune the fuel delivered at this point, since the mixture needs to be soggy rich just to keep the engine running. This is called open-loop control.

Once the engine has reached operating temperature, the computer switches to 'closed-loop' control. This means the computer receives feedback from an oxygen sensor as to whether the mixture is too lean or too rich, then it makes adjustments, then checks the sensor again, then makes adjustments, and on and on in an infinite loop.

To understand the principle, imagine if you were to close your eyes and type words on your computer keyboard. If you are a good typist, the words are probably correct, but you have no way to know if you made a mistake. That's open loop control. There's no feedback as to whether the desired result was obtained, you simply have to assume that the correct words are there. Now open your eyes. if you mis-typed a word, you now have the feedback that you messed up, and you can type in a correction. That's closed-loop, from your fingers, to the keyboard, to the screen, to your eyes, which control the fingers. See the loop?
I know how it works dude
 

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Discussion Starter #14
The O2 sensor being located in the head instead of the pipe doesn't matter. That makes it easier for it to heat up to operating temperature. Bazazz has had their fuel controller out for the CBR250R for several months. Your engine tuning shop shouldn't be having any problems.
That is correct but this controler is brand new and not out yet. Don't you think bazazz had their share of issues at first too?
Like I said they will call me back this week so i'll update you
 

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I understand the closed-loop/open-loop system, but there was some talk in another thread about the CBR's ECU "learning" how you ride and making adjustment to maximize performance in that area. That would mean you would get more performance at WOT and high RPMs if you spend more time there.

I felt that the CBR's ECU and controls weren't advanced enough to accomplish that, and it was just running the same preset map (based on a few variables, mainly temps) for all RPMs no matter how often you operate there.

If you get a chance, ask your tuning shop if the CBR's ECU can "learn" and make adjustments to increase power based on how you ride.

Thanks.


Jay
 

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I understand the closed-loop/open-loop system, but there was some talk in another thread about the CBR's ECU "learning" how you ride and making adjustment to maximize performance in that area. That would mean you would get more performance at WOT and high RPMs if you spend more time there.

I felt that the CBR's ECU and controls weren't advanced enough to accomplish that, and it was just running the same preset map (based on a few variables, mainly temps) for all RPMs no matter how often you operate there.

If you get a chance, ask your tuning shop if the CBR's ECU can "learn" and make adjustments to increase power based on how you ride.

Thanks.


Jay
Of course it can learn but it is not to increase power it is to correct the fuel trims. The system he described up there is the Short Term Fuel Trims. There are also Long Term Fuel Trims, those are based off of the adjustments in the STFT's to take some of the guess work out of the fueling. The reason for resetting the ECU is it will make it forget the LTFT's and re learn quicker. It can learn in the same way with out resetting but it will take a longer period of time.

As far as being advanced enough, it has to be. Back in the older days of carburation or mechanical fuel injection when you went up in the mountains the fuel system had to be adjusted for this. Now the computer completely compensates for this with the fuel trims and MAP sensor.
 

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While the bike's ECU can do SOME trimming in closed loop, it's only within a specified range which usually isn't enough to account for heavy engine rework as was done here.

I'm a bit surprised the bike is going into limp mode with an O2 eliminator though. The ECU may want to see more than just a stoch reading and actually see power draw from the heater element too? Buell's were notorious for this, just couldn't get the ECU to stop mucking with the mix, to the point that Dynojet stopped making PC3s for some models.
 

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O2 sensor with heater circuit.

The ECU may want to see more than just a stoch reading and actually see power draw from the heater element too?
If you are refering to the heater circuit for the O2 sensor for the cbr.

The O2 sensor that is used on the cbr is a single wire sense circuit. The ground circuit is thru the engine back to battery negative.

Their is no Heater Circuit for the O2 sensor on the cbr.
.
 
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