Does the Barbarian Jumper Mod Change the FI Map?

[temp357]

A quick question to the experts. Does the Barbarian jumper mod have any effect on the fuel injection mapping or does it merely control the acceptable level of air/fuel mixture?

I know the PCIII requires disconnecting the o2 sensor, but can the o2 sensor be left attached with the barbarian jumper mod?

thx

 

[Bounce]

yes

yes

 

[SkooterG]

Remember, Barbarian jumper is just SWAGing stuff. Also, it is only affecting fuel injection mapping at idle, and just off idle for the most part, whereas a PCIII adjusts the entire map. Yes, you leave the O2 sensor in place for the Barbarian Jumper Mod. (Not so for the PCIII)

A quick question to the experts. Does the Barbarian jumper mod have any effect on the fuel injection mapping or does it merely control the acceptable level of air/fuel mixture?

I ain't for sure on this, but to my knowledge it's apples vs. apples, or one in the same. IOW, the fuel injection mapping is what determines the air/fuel mixture. So I would say yes, the BJ affects the fuel injection mapping.

If I have said it once, I have said it a thousand times. Anybody performing the Barbarian Jumper needs to read the posts by forum member Torch in THIS THREAD.

 

[ionbeam]

The Barbarian Jumper (BJ) lets you change offsets to the basic fuel injection map. The fuel injection software is a 'one size fits all' program that gets tailored for each individual bike via the CO offsets. We then do the BJ which tweaks the tailor -- that is -- we blindly increase the factory determined offsets.

In theory Yamaha has a way to run each engine and determine the amount of correction the engine needs to hit target CO values. I don't know why so many '06s have the same offsets, but suspect that is not right. The reported offsets were all over the place during '03 and '04 when the BJ was first being done. I know at least one person has had the ECU replaced, wonder how the dealer handled the CO trim.

On the Gen I FJRs the O2 sensor is active only when the engine is up to operating temps and running as a fairly steady speed. That is the only time the FI system is running totally closed loop, all other times it is running from tables and little tweaks based on ~6 sensors. The Gen II FJRs are a very different setup. Time to take a good read from the '06 FSM.

Edit: I see Skoot was posting while I was typing, some overlap results.

 

[SkooterG]

Excellent, detailed, and informative post Alan.

 

[Fastmax]

In theory Yamaha has a way to run each engine and determine the amount of correction the engine needs to hit target CO values. I don't know why so many '06s have the same offsets, but suspect that is not right. The reported offsets were all over the place during '03 and '04 when the BJ was first being done. I know at least one person has had the ECU replaced, wonder how the dealer handled the CO trim.

I have been reading up on the similarity of the factory settings and the discussion over whether or not Yamaha actually took the time to set them up. I am curious as to whether or not I can use my infrared thermometer gun on the pipes to determine how close the settings are. If one is burning leaner than the others will it not show a higher temp reading on the pipe than a richer cylinder would? If I know the butterflies are all set the same, can I not then adjust all of the settings so that they show a similar temperature on the pipes? This way I would know all of my cylinders are burning the same and I can richen them from there. Does this plan work in the real world? Inquiring minds want to know.

Thanks

Roy

 

[temp357]

thanks skoot/ion !

So if I understand this correctly, if the system is running in closed loop doesn't it override anything the barbarian jumper mod or a pciii would output by throttling the air/fuel mixture back?

Incidentally, how does the pciii deal with the air/fuel mixture? When you disable the o2 sensor won't it run the bike too lean/rich as the atmospheric preassure changes?

thanks again for all the feedback

Ali

 

[jestal]

The fuel injection system always uses the basic fuel tables whether it is running closed loop or not. Those tables always serve as the baseline fueling values. The closed loop system just adds a correction to that base fuel table....it doesn't take over control of the fueling calculation completely.

In a speed density fuel injection system like the FJR has the base fuel table consists of a map of volumetric efficiency plotted in a three dimensional table of Manifold Absolute Pressure (MAP) and RPM. RPM is the speed portion of the tables and MAP indicates load on the engine. So, for any given speed and load condition there is a pre-programmed volumetric efficiency value in the table that is looked up and used in the fuel calculation.

The closed loop system just looks at what the O2 sensor is doing (indicating rich or lean) in the exhaust stream and adds a plus or minus multiplier to the base fuel calculation. So...it is not the main control feature, it is just an adjustment to the base fuel control. That is why the engine still runs fine if you disconnect the O2...it is just running on the basic fuel table with no closed loop correction.

Engines did this for decades....they ran off the base fuel calibration (whether it was a carbuerator or some sort of fuel injection) and they ran fine. The air/fuel ratio doesn't have to be that close to just drive good and make good power. But a 3-way catalytic converter MUST see exhaust gases at EXACTLY 14.7:1 to function. Hence the O2 sensor and closed loop. The open loop basic fuel calibration might get it close...to within 14.5:1 to 14.9:1 for example. Then the resluting correction from the O2 sensor input gets it right at 14.7:1 so the cat works.

The CO feature of the FJR was probably put into the system for two possible reasons:

One, each of the cylinders in an engine, any engine, flow slightly different amounts of air. During developement this can be measured and the different injectors can be assigned a slightly different mulitplier so that when the system fires that injector the correction factor is applied for that cylinder. The fuel injection system just looks at the engine as a whole and calculates a pulse width for the injectors to open to deliver the amount of fuel desired. Then the actual injector drivers are synced to engine rotational location so that each injector is fired at the appropriate time for that cylinder event. That is where the multiplier for each cylinder would come into play. Since the air flow characteristics of each cylinder would be the same engine to engine, in other words it is dependent on the engine/intake design, so it would repeat the same on all engines.

Two, each fuel injector is built within a certain flow tolerance. Typical industry standards are plus/minus 3 percent. Generally, the injectors are closer than that but over the long haul you could possibly see an injector that is 3 percent lean next to one that is 3 percent rich. If the specific flow rate for each injector were measured and known then this could be programmed into the individual cylinder fuel modifier to compensate for a rich or lean injector. Since each injector in production is flowed it would just require that the data be recorded and maintained with that injector and translated into the PCM for that fuel rail containing that injector. Touh accounting task in production but not impossible.

Possibly, since this was the first go round with a catalyst equipped FJR in the US Yamaha may have entered the flow data for each injector into the early bike's calibration to make the fuel delivery at idle and light loads more even.

They may have found this to be unnecessary with more production experience in the field and then set the various cylinder compensation values to match the individual cylinder air flow characteristics.

Just a guess but it would explain why early bikes are all different and later ones have the same values. The air flow rates of different cylinders would be characteristic of the engine/intake design, not each specific engine so all engines would have pretty much the same cylinder to cylinder air flow rates thus requiring a common set of compensation values for all those models.

Most every PCM has some sort of back door way of entering corrections or making modifications. The Barbarian jumper mod just enables this back door method to function. It doesn't change anything per se. If you use the BJM to adjust the individual cylinder correction values (the "CO settings") then it will affect the whole fuel map whenever the correction factor is used. Since the closed loop system will sense richness and put a lean offset into the system to compensate it would just pull out the extra fuel put into the correction via the CO adjustment. I suspect that the individual cylinder CO adjustment, made accessible via the BJM, is only applied when the system is operating without input from the closed loop system so the affect goes away as soon as you are off idle and the system is closed loop. So, the change wouldn't affect the whole fuel map in reality...just the idle and barely off idle portions. If you just wire the BJM and do not slew the CO adjustments then nothing has changed....you just have the capability to change it, that is all.

Since the engine is not under closed loop control at heavy throttle openings and WOT the "CO adjustment" may affect full throttle operation also. It COULD but I suspect that it does not. At heavy throtles the engine is calibrated rich, probably around 12:1 or so, for best power and engine protection. That is obviously richer than the cat will operate at (14.7:1) so the system is open loop at heavy throttles.

 

[BrunDog]

Jestal, as usual, a solid and detailed response.

I agree with all that you said except for the last comments. Anectdotally speaking, many riders, including me, have felt an improvement in steady speed surging. If this is considered "just off idle", than we are in agreement. If not, the CO offset is affecting more than you are stating, perhaps in both open and closed loop modes. Perhaps the offset is to accommodate individual flow characteristics of each injector, and the O2 feedback cannot nullify the offset?

-BD

 

[temp357]

Thanks for the GREAT writeup jetsal i had to read it a few times, but i think i got it.

Is there any way to tell when the system goes from open loop to closed loop?

 

[jestal]

Jestal, as usual, a solid and detailed response.
I agree with all that you said except for the last comments. Anectdotally speaking, many riders, including me, have felt an improvement in steady speed surging. If this is considered "just off idle", than we are in agreement. If not, the CO offset is affecting more than you are stating, perhaps in both open and closed loop modes. Perhaps the offset is to accommodate individual flow characteristics of each injector, and the O2 feedback cannot nullify the offset?

-BD

I wouldn't argue with you because I do not really know how Yamaha has it set up.....but.....if the change affects the fuel map in the area of operation where the system would go closed loop then the closed loop system would see the "richness" and just dial it out with the closed loop correction. Since the system is designed to reduce emissions under the most widely used of operating conditions for NOx...that being part throttle cruising where you would spend most of your time.....I wouldn't expect the CO adjustment to still come into play at part throttle if you just added fuel to the CO correction across the board. It just seems counterproductive.

The oxidizing function of the cat works any time the system is lean or at stochiometric. HC and CO are eliminated by oxidizing so in conditions where HC and CO are an issue (overruns, idle ) the system is generally driven lean. NOx is eliminated by the reducing action of the catalyst. For NOx to be "reduced" (no pun intended) the cat needs stochiometric or rich operation. NOx is not an issue at idle or at WOT so the time for being concerned about NOx is cruising at part throttle. So, it is just about a given that the system will be closed loop and at 14.7:1 at part throttle cruise. Adding fuel to the CO adjustment would be counterproductive to this so it must be overridden at part throttle some how or the closed loop control just takes the fuel out..which would negate any anti-stumble improvement suspected to be due to the CO adjustment.

It is sort of a conundrum I guess without really knowing. If the CO correction is meant to adjust for different injectors then it could go into all operating conditions, I guess. Most of the time, the injector corrections tend to be used in the industry at low pulse widths (like at idle and very low throttles) because that is where the biggest impact is. So...I just do not know.

I have disconnected the O2 on mine and have the PCIII on it and have played with the PCIII correction table quite a bit. I did go in and change the CO settings by adding 10 counts across the board on all four cylinders to see what the effect would be. It certainly richened it up at idle but did not seem to affect it off idle and cruising. I don't have EGT or air/fuel data but the seat of my pants and throttle response did not seem to change with the plus 10 counts of CO adjustement so that also seems to me to indicate that the CO adjustment was only effective at idle. Maybe it is a percentage adjustment and the percentage is relatively low at higher pulse widths so I just didn't notice.

In any case, if there is a little excess fuel at idle it would tend to cover any off idle surge or stumble during a transient just due to the latent fuel in the port being in excess. That would tend to cover off idle a bit even if the CO adjustement was not effective then.

Wish I had a Yamaha cal engineer to talk to for 5 minutes....LOL.

 

[SkooterG]

Wish I had a Yamaha cal engineer to talk to for 5 minutes....LOL.

Don't we all. Don't we all.