Verifying what I've learned about EFI on the FZ6

[Chris Parker]

Ok, so I've been looking around a bit and want to make sure I have a clear picture of how the EFI system works on our bikes. It seems to be a bit primitive.

Basically it has one static fuel curve, which is adjusted up and down on the y-axis from feedback from the o2 sensor, correct?

So the bike is able to adjust for humidity and altitude, but is NOT able to adjust for mods because the mods MAY require a different fuel curve due to different airflow at various RPM's versus stock.

...correct?

EDIT: Forgot to put in that I was referring to the 07-later models.

 

[bd43]

I wouldn't call the EFI primative by any means and according to the service manual on page 1-3, the ECU utilizes other sensors including O2 to determine the right amount of fuel to inject.....

See highlighted attached extracted pages from the manual.

 

[Chris Parker]

Yes, I've read that section. But again, it says the bike is able to compensate, but to what extent? Is it simply increasing the fueling based upon a set fuel curve or is it doing real-time adjustments?

In other words, the engine is going to consume air at similar proportions throughout the RPM range even at different air densities when it's stock.

But the airflow may not follow the same curve once and exhaust and intake has been added. It may require more fuel in certain parts of the RPM range than the proportions provided by the stock curve.

Is the ECU able to do this? Or is a programmer required to change the algorithm?

 

[jsw4178]

I am pretty happy with my EFI. I added a Two Bros Juice Box to my FZ6 and it seems to make an overall difference with the added Carbon exhaust and K&N air filter.

 

[Hellgate]

Chris - Well yes and no, sort of. I am not an expert but here is what an expert told me as he was dyno tuning my '07.

From 0 to 7,000 rpm and 0 to 10% throttle opening our bike is closed loop due to the 02 sensor.

With a tuning device, Power Commander, Juice Box, Bazzaz Box, etc. you can by pass the CPU and tune to your hearts desire within a "safe" range.

If you mod you bike, exhaust, air box/filter, CAT eliminator you should disconnect your battery and the bike with "retune" itself, for the most part, for the changes you made.

You can also tune through the CPU via the o2 sensor and make some nice gains.

Our bike does not have a Mass Flow Sensor, only a temp sensor in the airbox so I don't think it will adjust automatically for humidity and altitude, how ever the 02 sensor with keep you in a "safe" range. A dyno tune will do that for you.

And yes you are correct, it is primative compared to a modern MoTec system.

With a PCIII or other box you can made a nice improvement in smoothness, torque and a bit more top end power. The most I've seen out of our bike is 100hp at the wheel in an inertia type dyno. An Eddie Current dyno will read about 15% less.

That is what I know and I'm sticking to it.

How come, gotta project planned???

 

[Chris Parker]

Thanks for the information!

I have some vague plans in mind for the intake, I'm more or less just trying to learn as much as I can before trying to attempt any projects. I have a lot of resources and I'm a perpetual efficiency freak.

So here is my next question: do you have to buy a power commander to get dyno tuned?

There is a harley dealership close by that does dyno tuning... but I'm hesitant to get a four cylinder bike tuned by harley guys. I'm always VERY skeptical of letting anyone touch my machines, I do all my own work unless it requires equipment I don't possess.

 

[jy116]

good info, thanks. i'm new to EFI and wonder if I can just put on new pipes w/o tuning. i really just want the sound and could care less about max power gains. As long as the engine is running efficiently, I'm happy.

 

[urbanj]

The most important sensor that everyone seems to miss is the pressure sensor. It's the only way the ECU knows the engine load. Every other sensor is supplementary and only refines the output.

Look at EFI as inputs and outputs. The ecu will have a base table and then based on the various inputs, will modify it's output. The output is the fuel injectors pulse width(PW).

The O2 sensor is for emissions only and only used during constant throttle and light loads. The o2 sensor is a narrow band sensor with means it pretty much reads only rich or lean and no specific value. So under closed loop, when the ecu is taking the feedback from the o2 sensor, the ecu will trim or add fuel. This is even after all of the other data has been crunched to determine the fuel injectors PW.

Under load the ECU takes in all the data, crunches it and modifies it's tables to determine what the fuel injectors PW should be. Even in stock form this isn't always perfect especially on a product that isn't higher end or has as much engineering put into it. This is why a PC3 dyno tuned on a stock bike will always be better. A stock system can compensate a little for additional air flow (mods) but there will be a point where it reaches it's programming limit. (come on it's oem)

Enter the PC3. when it's all said and done, what the PC3 is is a highly customizable piggy back ecu. It is installed inline with the OEM ECU which means it takes the data that is coming in and modifies it. This allows the ECU to think it's happy while still providing the engine with all the fuel it needs or doesn't need.

 

[urbanj]

Thanks for the information!

I have some vague plans in mind for the intake, I'm more or less just trying to learn as much as I can before trying to attempt any projects. I have a lot of resources and I'm a perpetual efficiency freak.

So here is my next question: do you have to buy a power commander to get dyno tuned?

There is a harley dealership close by that does dyno tuning... but I'm hesitant to get a four cylinder bike tuned by harley guys. I'm always VERY skeptical of letting anyone touch my machines, I do all my own work unless it requires equipment I don't possess.

You'll need a way of modifying the fuel tables to dyno "tune" but you can get it dynoed with nothing. Also, I'd go to a place that is familiar with the product they are working on.

 

[04efi]

Chris - Well yes and no, sort of. I am not an expert but here is what an expert told me as he was dyno tuning my '07.

From 0 to 7,000 rpm and 0 to 10% throttle opening our bike is closed loop due to the 02 sensor.

With a tuning device, Power Commander, Juice Box, Bazzaz Box, etc. you can by pass the CPU and tune to your hearts desire within a "safe" range.

If you mod you bike, exhaust, air box/filter, CAT eliminator you should disconnect your battery and the bike with "retune" itself, for the most part, for the changes you made.

You can also tune through the CPU via the o2 sensor and make some nice gains.

Our bike does not have a Mass Flow Sensor, only a temp sensor in the airbox so I don't think it will adjust automatically for humidity and altitude, how ever the 02 sensor with keep you in a "safe" range. A dyno tune will do that for you.

And yes you are correct, it is primative compared to a modern MoTec system.

With a PCIII or other box you can made a nice improvement in smoothness, torque and a bit more top end power. The most I've seen out of our bike is 100hp at the wheel in an inertia type dyno. An Eddie Current dyno will read about 15% less.

That is what I know and I'm sticking to it.

How come, gotta project planned???

Ok not to push this because I did it as well. The disconnect battery thing. I replaced the cat yesterday. After doing so I went to buy oil from my dealer and while I was there I had a chance to talk to the mechanic they have. I was asking him about if what I did with the battery was needed. He told me it don't hurt but it also wont effect the bike either. He said yamaha ECU is designed to only adjust while bike is running by gathering the numbers it needs. He said by removing the battery you don't even clear the old numbers because its stored on ram just like a flash drive. This dude really seems like he knows what he is doing. He told me to allow bike to warm up, then run a slow sweep into all RPMs. After getting the about 11k or redline which i think mine was 12k he said to release throttle and the bike will calm back down to idle. He said allow to run for about 5 more mins before driving. He said that is what is handbook tells them to do when adjusting anything with the EFI. Anyone else confirm this???

 

[tuningfork]

The most important sensor that everyone seems to miss is the pressure sensor. It's the only way the ECU knows the engine load. Every other sensor is supplementary and only refines the output.

Look at EFI as inputs and outputs. The ecu will have a base table and then based on the various inputs, will modify it's output. The output is the fuel injectors pulse width(PW).

The O2 sensor is for emissions only and only used during constant throttle and light loads. The o2 sensor is a narrow band sensor with means it pretty much reads only rich or lean and no specific value. So under closed loop, when the ecu is taking the feedback from the o2 sensor, the ecu will trim or add fuel. This is even after all of the other data has been crunched to determine the fuel injectors PW.

Under load the ECU takes in all the data, crunches it and modifies it's tables to determine what the fuel injectors PW should be. Even in stock form this isn't always perfect especially on a product that isn't higher end or has as much engineering put into it. This is why a PC3 dyno tuned on a stock bike will always be better. A stock system can compensate a little for additional air flow (mods) but there will be a point where it reaches it's programming limit. (come on it's oem)

Enter the PC3. when it's all said and done, what the PC3 is is a highly customizable piggy back ecu. It is installed inline with the OEM ECU which means it takes the data that is coming in and modifies it. This allows the ECU to think it's happy while still providing the engine with all the fuel it needs or doesn't need.

Great description however I believe any mods you make in the closed loop region will get cancelled out over time on a 2007+ as Hellgate mentioned.

On the older bikes you can tune any portion of the fuel curve you want.

The PC3 is effectively wired in between the ECU and the injectors and allows you to modify the pulse widths +/- % from the pulse supplied by the ECU. It does not alter any feedback signals to the ECU. The PC3 uses TPS and engine rpm as its map inputs only. The PC-V has an additional analog input I believe which should allow for additional map control.

For those looking for additional information the OEM EFI system it is referred to as a "speed-density" system...inputs are inlet air temp, coolant temp, rpm, inlet pressure, and throttle position. This is enough information to accurately calculate engine "load" and engine operating condition (ie cold start, closed loop, idle, WOT, etc.) over varying temps, air pressures/altitudes, etc. The O2 sensor trims out the calculation using average exhaust gas O2 over the 4 cylinders and allows some map shift over time due to component wear, tolerances, fuel burn, etc.

The engine timing calculation is also load based (ie 3-d map).

Google up "speed density" and you will get a lot of info.

 

[Gilo-FZ6]

, I'd go to a place that is familiar with the product they are working on.

this why im hesitant to buy a PC5 at this moment in time..theres 2 varified dynojet tuners in riding distance to me but how much will they know this early into the PC5's release

 

[tuningfork]

Ok not to push this because I did it as well. The disconnect battery thing. I replaced the cat yesterday. After doing so I went to buy oil from my dealer and while I was there I had a chance to talk to the mechanic they have. I was asking him about if what I did with the battery was needed. He told me it don't hurt but it also wont effect the bike either. He said yamaha ECU is designed to only adjust while bike is running by gathering the numbers it needs. He said by removing the battery you don't even clear the old numbers because its stored on ram just like a flash drive. This dude really seems like he knows what he is doing. He told me to allow bike to warm up, then run a slow sweep into all RPMs. After getting the about 11k or redline which i think mine was 12k he said to release throttle and the bike will calm back down to idle. He said allow to run for about 5 more mins before driving. He said that is what is handbook tells them to do when adjusting anything with the EFI. Anyone else confirm this???

I don't know 100% if there is keep-alive memory in the ECU, but the goal of the battery disconnect is to zero out the learned values then re-adapt with the mods. The ECU is always adapting though so the tech's description should also work too, although it might take it longer to "learn".

 

[Guitar Man]

I'm running the PC5 on the stock map and it runs better. No other mods. Just throwing that out there.

 

[krid80]

Thanks for the information!

I have some vague plans in mind for the intake, I'm more or less just trying to learn as much as I can before trying to attempt any projects. I have a lot of resources and I'm a perpetual efficiency freak.

So here is my next question: do you have to buy a power commander to get dyno tuned?

There is a harley dealership close by that does dyno tuning... but I'm hesitant to get a four cylinder bike tuned by harley guys. I'm always VERY skeptical of letting anyone touch my machines, I do all my own work unless it requires equipment I don't possess.

where in Illinois are ya? We do dyno tuning with and without a power commander. There is a sticky at thhe top of the "mods" section that details adjusting the factory carbon monoxide (co) levels. That is how Yamaha (doesn't) tell us to adjust for aftermarket exhaust pop. (doesn't because it is locked out and you have to be a dealer to call the tech line to find out which wire to ground out to unlock such tuning) It is primitive tuning with only two adjustable points but it is something and doesn't cost $350 for the power commander.

 

[tuningfork]

Great description however I believe any mods you make in the closed loop region will get cancelled out over time on a 2007+ as Hellgate mentioned.

On the older bikes you can tune any portion of the fuel curve you want.

The PC3 is effectively wired in between the ECU and the injectors and allows you to modify the pulse widths +/- % from the pulse supplied by the ECU. It does not alter any feedback signals to the ECU. The PC3 uses TPS and engine rpm as its map inputs only. The PC-V has an additional analog input I believe which should allow for additional map control.

For those looking for additional information the OEM EFI system it is referred to as a "speed-density" system...inputs are inlet air temp, coolant temp, rpm, inlet pressure, and throttle position. This is enough information to accurately calculate engine "load" and engine operating condition (ie cold start, closed loop, idle, WOT, etc.) over varying temps, air pressures/altitudes, etc. The O2 sensor trims out the calculation using average exhaust gas O2 over the 4 cylinders and allows some map shift over time due to component wear, tolerances, fuel burn, etc.

The engine timing calculation is also load based (ie 3-d map).

Google up "speed density" and you will get a lot of info.

Just wanted to update my post, I was looking at the PC-V maps and installation guide and see some differences between the PCIII that are noteworthy and maybe contradictory to what I posted earlier which was pretty much PCIII specific. The PC-V DISCONNECTS THE FACTORY O2 sensor...so they now must be be supplying a fake signal to the ECU to allow a work-around for the built-in fuel trims (unlike PCIII). From looking at the "stock map" they are def. doing some fueling adjustments in the old "closed" loop region. According the the baseline auto-tune maps they are pretty much setting the bike to run between 13.6:1 and 13:1 with a good portion of it set to 13.2:1.

So this should in theory offer more power but only a dyno would know for sure. I wonder what effect this will have on the CATs though.

I don't see any accel enrichment values suggested or supplied for the stock map either.

The install instructions say to use the temp input for the new analog map control, and also to use the speed input...however the freebie map does not use them for anything (ie same maps for all gears and temps). But this does add a lot of customization potential.

 

[deeptekkie]

Thanks for the information!

I have some vague plans in mind for the intake, I'm more or less just trying to learn as much as I can before trying to attempt any projects. I have a lot of resources and I'm a perpetual efficiency freak.

So here is my next question: do you have to buy a power commander to get dyno tuned?

There is a harley dealership close by that does dyno tuning... but I'm hesitant to get a four cylinder bike tuned by harley guys. I'm always VERY skeptical of letting anyone touch my machines, I do all my own work unless it requires equipment I don't possess.

I too, would be extremely reluctant to do this!

 

[tuningfork]

Some Harley shops may tune with PowerCommander, but most I have seen use the HD Race Tuner which actually modifies the maps inside the factory ECU (ie not a piggyback device). You might be ableto get a decent tune here but I would tryt o find someone who ahs experince with Yamahs if possible.

You can search for tuning centers on dynojet's website, and also check out factorypro.com, they also do tuning (which is considered by some to be more accurate actually because of differences in the dyno and the use of 4-gas not just wideband AFR).

Some dynojet center do use 4-gas and non-inertia dynos though.

 

[D1ck3y0da]

Great description however I believe any mods you make in the closed loop region will get cancelled out over time on a 2007+ as Hellgate mentioned.

On the older bikes you can tune any portion of the fuel curve you want.

The PC3 is effectively wired in between the ECU and the injectors and allows you to modify the pulse widths +/- % from the pulse supplied by the ECU. It does not alter any feedback signals to the ECU. The PC3 uses TPS and engine rpm as its map inputs only. The PC-V has an additional analog input I believe which should allow for additional map control.

For those looking for additional information the OEM EFI system it is referred to as a "speed-density" system...inputs are inlet air temp, coolant temp, rpm, inlet pressure, and throttle position. This is enough information to accurately calculate engine "load" and engine operating condition (ie cold start, closed loop, idle, WOT, etc.) over varying temps, air pressures/altitudes, etc. The O2 sensor trims out the calculation using average exhaust gas O2 over the 4 cylinders and allows some map shift over time due to component wear, tolerances, fuel burn, etc.

The engine timing calculation is also load based (ie 3-d map).

Google up "speed density" and you will get a lot of info.

So adding inlet air pressure to my pcv w/auto tuner will better allow it to make a better map? I've noticed my auto tuner likes to add crazy amounts of fuel (spmetimes +50%) very low in rpm (2500k-7000ishk) @2%- 10% throttle and you can feel it when it hits a crazy high number. I normally have to go into map and adjust. My next question is if I can add pressure sensor how do I calibrate it? Any information will be appreciated. Thanks.

 

[Gary in NJ]

This is nearly a 12 year old thread, and tuningfork has not been here since May of 2012.