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vcyclenut said.....
"We both noted that during deceleration ,even though decel cut is disabled in the software, as soon as we got to 3000 rpm the air fuel would go very lean and the bike would begin to pop and that making adjustments to the area of the fuel chart that the is being used didnt make a difference. "

I thought popping on decel was due to a rich condition, i.e., unburnt fuel? Why does a lean fuel condition result in popping?
 
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Discussion Starter · #44 ·
I will test engine braking tomorrow in all gears and see if the numbers in the ETV tables translate to how it feels.
I've done some testing, but it's hard to conclude anything in regard to any differences in the amount of engine braking between the gears. The "push" however is much more prominent in gears 1-4 compared to gears 5-6.
 

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vcyclenut said.....
"We both noted that during deceleration ,even though decel cut is disabled in the software, as soon as we got to 3000 rpm the air fuel would go very lean and the bike would begin to pop and that making adjustments to the area of the fuel chart that the is being used didnt make a difference. "

I thought popping on decel was due to a rich condition, i.e., unburnt fuel? Why does a lean fuel condition result in popping?

common misconception and one I had myself when I started in my tuning journey how ever long ago

both lean and rich fuel mixtures cause fuel to be left over and unburnt.

Most people are under the misconception that if you just take fuel away ( make it leaner) you will get better fuel mileage. This is only true to a point and its fairly narrow window. I find with my methods of tuning that even with adding fuel ( making richer) I can actually sometimes achieve better MPG if the area that I am adding fuel to was too far on the lean side and getting incomplete burns. Obviously any time there is fuel left over this is not an efficient condition.

So by correcting it you get a win win win, better power, smoother throttle response and better fuel mileage.

I am not saying my tunes always get better MPG, it depends on several factors , but it does happen in windows of throttle positions and rpm's
 

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Together with the recall changes to the ETV, these are really interesting numbers. If the ETV tables effect closed throttle it could explain why many are now feeling this issue at 3000 rpm after having the ECU flashed. But, at least for me, something else is causing additional "push" or dip in engine braking apart from just the changed ETV numbers, because I feel it in 5-6 gear as well, although not as pronounced. A very interesting question here is: Does everyone who now has this issue also have it in 5:th and 6:th gear?

I will test engine braking tomorrow in all gears and see if the numbers in the ETV tables translate to how it feels.

as I said I dont believe these tables are affecting closed throttle, but I will test it.

if you do the math,

throttle closed

if its really closed then 0 times any multiplier is 0

if it was open 1 or 2%, which at 3000 rpm it could not be open more then that or the bike would not slow down, the differences in the multipliers would be almost nothing.

I also could feel the same effect in all gears and this table is not the same for all gears

I honestly still think it is related to the decel cut issue that has been noted since the beginning. Or at least what appears to be a decel cut issue.

These tables could be something completely unrelated to normal throttle use and could be used by the nannies or they could be left over from a different bike or just not used. Woolich tells me ( and they are the ones looking at the actual code in the ecu) its not uncommon to have tables in the ecu that are not used at all

People notice things all the time that have been there since the bike was new after getting a flash. People pay way more attention looking for issue. I get about a call a week from a customer that after the flash they started the bike and their ABS light is on and they think its a problem. When I tell them that their bike has had the ABS light on every single time they have started the bike since it was new, and the bike has to roll a little bit to send a signal to the wheel speed sensors and shut it off. I usually get a few seconds of disbelief silence and some people actually argue with me.
 

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:LOL: Like the odometer in the ECU people? (I think it was...)

haha I have had people switch their odometer from miles to km and blame me for almost doubling the miles on their bike.

the yoshimura system ill be testing next is due here today, currently there is no exhaust on my bike . hoping to get it mounted tomorrow and get some testing done
 

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To add to my already reported experience: today I confirmed that the significant reduction in engine braking as engine speed drops below 3,000 RPMs is present in all gears. It's more noticeable in lower gears, but, of course, that's because the engine has more leverage on the wheel in lower gears.
 

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I feel the multiplier tables do affect the decel at closed throttles, from testing I did today I increased the values at 3000 an 3050 rpm in the first 4 gears above the values at 2000rpm in affect making the blade slightly more open less compression braking above 3000 an 3050rpms this seems to have reduced the affects of the injector coming back on as injector cut goes from injector off to injector on. As David mentioned Woolich will be looking into the injector cut disable in the future so we should be able to remove it completely one day.
 

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I was curious about this so I tried to see if I'd feel anything odd on the engine braking. I don't have my bike flashed with the recall fyi.

My takeaway is, I'm surprised anyone even noticed. I realized that when I ride I almost never rely on engine braking below 5000 rpm. Below that I'm practically coasting because engine braking is almost negligible.

I just don't find engine braking under 3000 rpm useful I guess?
 

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I spent a lot of time last week, going back and forth between the stock pre recall image, the stock recalled image , my flash pre recall image and my flash with recall image

both images as they cross over 3000 rpm while decelerating the bike burbles ( as decel cut turns off) and there is a split second that the engine braking lessens

the recalled image does have less overall engine braking below 3000 rpm adding to the feeling

with my flash with either image its barely noticeable, there is a slight release with the burble and then engine braking returns as before

The prementioned table does effect engine braking but it is not the cause of the feeling. As no matter what I put them at the burble and little release it there
 

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Discussion Starter · #53 · (Edited)
I spent a lot of time last week, going back and forth between the stock pre recall image, the stock recalled image , my flash pre recall image and my flash with recall image

both images as they cross over 3000 rpm while decelerating the bike burbles ( as decel cut turns off) and there is a split second that the engine braking lessens

the recalled image does have less overall engine braking below 3000 rpm adding to the feeling

with my flash with either image its barely noticeable, there is a slight release with the burble and then engine braking returns as before

The prementioned table does effect engine braking but it is not the cause of the feeling. As no matter what I put them at the burble and little release it there
Wow, I really appreciate the time you put into this.
In case there is no hidden stuff going on, could it be that your results point towards a hardware behaviour? And that there is some sort of accumulation of fuel, kind of like a ketchup effect, that gets released when the fuelling comes back on? And that this effect may vary in amount and duration between bikes?
I think, at least for me, I would never have a problem with this if decel cut was on until 2000-2500 rpm. Or if there was no injector cut at all during decel [edited], but that would probably lesson engine braking and increase fuel consumption.
 

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Wow, I really appreciate the time you put into this.
In case there is no hidden stuff going on, could it be that your results point towards a hardware behaviour? And that there is some sort of accumulation of fuel, kind of like a ketchup effect, that gets released when the fuelling comes back on? And that this effect may vary in amount and duration between bikes?
I think, at least for me, I would never have a problem with this if decel cut was on until 2000-2500 rpm. Or if there was no decel cut at all, but that would probably lesson engine braking and increase fuel consumption.

id have to test multiple bikes to be sure but I think its likely pretty consistent.

for me once im rolling the only time I drop to 3000 rpm's is when coming to stop.
 

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id have to test multiple bikes to be sure but I think its likely pretty consistent.
Seems very likely.


for me once im rolling the only time I drop to 3000 rpm's is when coming to stop.
Some of the tighter roads around LA have hairpins for which I drop below 3,000 rpm when entering downhill in second gear.

Suppose I could drop all the way to first, but I'd rather have consistent engine braking! :unsure:
 

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The only way to fix this is to remove the injector cut function on de-cell which we cant at the moment.
 

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Discussion Starter · #57 ·
The only way to fix this is to remove the injector cut function on de-cell which we cant at the moment.
Yes, I got it the wrong way round in my last post, this is what I meant to write. But I think I would actually prefer having no injector cut to make engine braking a little less harsh. I guess that function is locked due to emission regulations?
 

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Seems very likely.




Some of the tighter roads around LA have hairpins for which I drop below 3,000 rpm when entering downhill in second gear.

Suppose I could drop all the way to first, but I'd rather have consistent engine braking! :unsure:

yea I am not lucky enough to have roads like that around here
 

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Yes, I got it the wrong way round in my last post, this is what I meant to write. But I think I would actually prefer having no injector cut to make engine braking a little less harsh. I guess that function is locked due to emission regulations?
I can also go either way on this...with or without engine braking would be fine as long as I can be confident going into a corner that I can ease out the front brake lever smoothly and not have to squeeze it more if the rpm goes below 3k.
 

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Discussion Starter · #60 ·
The only way to fix this is to remove the injector cut function on de-cell which we cant at the moment.
This is actually very interesting, I didn't know the injectors were compelety off during decel above 3000 rpm. If the injector cut could be removed it would probably result in smoother throttle response when initiating throttle above 3000, given how much you can feel the injectors coming alive when hitting 3000 during decel. Come to think of it, mine does feel a bit jerky, more than the one I drove a few months ago.
 
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