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So, i got the motor settled back and wanted to experiment with that yuminashi/keihin 'plug and play' ecu that was mentioned a few weeks ago.

I stuffed it in and set the timing to zero on the PCV as i have no idea what the curve is on the new unit. fired it up and left the same fuel trims in the PCV as was in there with the old (stock) ecu.

Initially, it ran really rich. since the new ecu i am sure had a richer afr target, this made sense. so i set the cells across the board int eh auto tune trim tables to -5, and it then at least got rideable.

I have to say, the ecu learned very quickly. in the closed loop , the afrs were at 13-13.2 and hit targets in open loop very fast. The bike ran smoother as well, somewhat, and was atad more responsive. since there's no rev limiter in the ecu anymore, i set the fuel tables at 11k and up to 11 to act as a soft limiter, and retarded the timing back 3 degrees.

I need to get the idle sorted a bit, seems ok but not perfect, but thats about the only complaint so far.

my plan is to see if the PCV can now be used to tune the cells from 0-60 and not fight the ecu. i'm not sure. i'll get a solid map done, than test this later. BUT, the PCV/WB2 does play with the yuminashi/keihin ecu. IF it can do the closed loop area now as well, us legacy power commander users can now get full tunability in the full range of the map.

considering the -5 setting in the auto tune helped it settle done initially, i'm guessing it might actually work.
Welcome to planet earth... :)
 

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Im running a finbo ecu on my high compression 125 build and it rips, I imagine that the yuminashi would be about the same but with the cold start function working.
I believe they're similar. Except it's odd in that the Yuminashi doesn't have a cold engine fast idle function like the stock ECU, and yet it cold starts easily with no throttle input, and cold idles at the regular hot idle rpm without dying. When it cold starts and idles, I can smell fuel so the mixture is richened up considerably tobe able to slow cold idle without dying.
 

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It sounds perfect for your setup.
It is... but just for bolt on mods. No downloads, no programming, no mapping, no reflashing, no resetting.

Not being able to adjust it makes it not very useful for high comp builds. They're a bit...sensituve. OP is trying to see if those of us with PCV's can get the best of both worlds by using the PCV to further fine tune it, which would be amazing. I hate my power commander. Haha.
You'd think someone would come up with a product like the Yuminashi ECU that would dial in engine operating parameters for BBK's without needing peripherals. The present systems offered seem so awkward clumsy convoluted and expensive.
 

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It is... but just for bolt on mods. No downloads, no programming, no mapping, no reflashing, no resetting.



You'd think someone would come up with a product like the Yuminashi ECU that would dial in engine operating parameters for BBK's without needing peripherals. The present systems offered seem so awkward clumsy convoluted and expensive.
Tuning is very case by case. That's exactly what the yuminashi and finbro ecu are shooting for, but what's good for you isn't good for me. With your bolt on mods you can run 13.5 or even 14:1 and still be perfectly fine. If I run that it'll cook my engine. I run 13.2 - 12.6:1. Also, different cams have different power bands, some people live at high elevations, etc. There are too many variables for a pre-set AIO.
 

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Discussion Starter #25
So, as an update i've been riding the grom the past 2 days to work.

Its pretty much dialed in with the full map being tuned. However, as i sort of suspected might happen, the mid-range was fighting a bit to get it perfectly dialed between the ecu, the pcv map in autotune, and the WB2.

a bit more explanation:
what happens is it was just finishing auto dialing in to 13.0 afr under 80%, in the closed loop area of a std pcv, (which is what the wb2 is designed to handle on a stock grom ecu), it was trying to finalize in and would swing back and forth on the afrs a bit watching the gauge. (like from 11 to 14, then occasionally flip to 10 or 16 briefly)

so, since the map was already populated and close in the fuel cells to maintain 13-ish under 80% throttle, i then reverted the afr target to '0' to let the wb2 adjust only under 80%. this seems to be really good after developing a base map 'the wrong way'. keep in mind, i'm running a 4 gear map, a really big injector, and a custom intake and exhaust on a ported and high compression (.018" shaved off the cyl) motor. so, i need a lot of fuel flow up high, which makes for tuning issues down low as the injector will struggle with not running too rich in lower rpm load conditions. The yuminashi ecu had a pretty fat map down low when combined with my hardware.
By letting the pcv autotune/write a map under 80% by using a target afr of 13, this allowed the trims to be set 'close to enough' in the static map to run 13.0ish under 80%, and give a good starting base map for the wb2 to adjust from. The yuminashi ecu itself with the pcv had a hard time trimming down enough to run lean enough to work right under 6k. it probably would have gotten there eventually, but i wanted to play with its capabilities.

this morning, i ran the map with the under 80% afr target set to zero as most units are(but with the base map populated), and it is smoothing out greatly. anything over 80% has been fine for a fee weeks, its dialed in on 80%-wot and working beautifully. The under 80% afrs were definitely more stable today and were 12.9-13.2 on average with a few blips the wb2 and the yuninashi ecu were handling. so, for me, this setup is working.

I could have changed the injector im sure, or tried to run the ecu alone and probably been 'ok', but i like running individual gear maps, and the pcv does rev limit where its set, which the yuminashi ecu wont.

I'm not saying this setup is for everybody, not by a LONG shot, but since i had the pcv already, its a small investment to make for drive-ability and control of the maps. .02
 

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Discussion Starter #27
the problems were coming from the wb2 and the pcv fighting to dial in under the 80% with a target afr map in place trying to autotune against each other, so apparently id DOES have a closed loop portion like a stocker. (not surprising). right now, as of this morning, its installed/setup like a regular pcv/wb2 and zero afr map under 80%, with the yuminashi ecu in place of the stock unit. the main difference is it has static values that were wrtitten to the map in the closed loop on the pcv tables, and the wb2 is now tuning to 13, but over the static values (as a starting point because the yuminashi ecu was so out of whack out of the box). If nothing else, it removes the hiccup where the stock ecu's rev limiter was when running a powercommander.
 

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when we in Northern Calif started tuning with PCV-WB02 we found a lot of controlling going on between the piggyback ECU and the PCV, when we switched over to a standalone ECU such as Aracer, Hodar, Finbro, Yuminashi we found that any problems centered around the size of the engine-BBK or stock, the size of your throttle body and F/I, the air filter system and exhaust system, the density of the air temperature in the location you where riding, the type of gas you used. Yes the stand alone ECU did not have to fight with any other ECU and most of the stand alone ECU uses the stock A/F sensor that is attached to head of the grom. The only time the other A/F sensor that is attached to the exhaust pipe is used is when you add the auto-tune to the Aracer circuit. We found that stand alone ECU trumps the piggy back ECU by a lone mile with less headaches esp with the 4v BBK kits such as Takegawa 181, Koso 170-4v or the new 181-4v, Finbro 183-4v Finbro 204-v4 or the one off 241-4v engine.

You want full control of your engine the Aracer RC1 is the top dog
 

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Tuning is very case by case. That's exactly what the yuminashi and finbro ecu are shooting for, but what's good for you isn't good for me.
I understand. There's a simple solution for me... a product I don't need to mess around with.

With your bolt on mods you can run 13.5 or even 14:1 and still be perfectly fine. If I run that it'll cook my engine. I run 13.2 - 12.6:1. Also, different cams have different power bands, some people live at high elevations, etc. There are too many variables for a pre-set AIO.
I'm surprised that no one makes make a stand alone module that will self learn to run from 13.2 to 12.6 A/F. You're obviously not the only one with this issue.
Just look at all the trouble you're going through trying to get your engine to run without self destructing.
Seems like a great business opportunity for someone to fill that need.
 

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We found that stand alone ECU trumps the piggy back ECU by a lone mile with less headaches esp with the 4v BBK kits such as Takegawa 181, Koso 170-4v or the new 181-4v, Finbro 183-4v Finbro 204-v4 or the one off 241-4v engine.

You want full control of your engine the Aracer RC1 is the top dog
Cisco I believe you are mising the point of Marks thread... This is related to improving on the use of the Pcv/wbc with Yuminashi ECU, talking like Minsc doesnt know the difference between Piggyback and Standalone,,, Shessh!
 

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there are plenty of standalone units that can tune to different AFRs. they all used wideband o2 sensors. hoedar makes one, aracer does, among others.

you aren't going to get reliable AFRs outside of a very narrow range using the stock o2 sensor. this is why all the standalone ecus that use the stock o2 sensor use it for closed loop only in low throttle openings when being lean isn't a big deal, when you reach larger throttle openings they all revert to open loop due to the limitations of the narrowband sensor. while some have suggested otherwise, the manufacturers themselves have said this is exactly what they do.


to tune reliably to a specific AFR, you need to use wideband feedback, for obvious reasons. this is what you get from the wideband standalone options. it's not a hole in the market, it's a requirement of the application.
 

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the guys having problems aren't running full standalone with wideband feedback.


they are running piggyback with an ecu that uses narrowband feedback, when their piggyback device uses wideband feedback. this creates a feud between the two fuel controllers. when the wideband piggy back tuner adds fuel the narrowband standard ecu sees it and pulls fuel out of the base table, this results in the overall fuel being reduced as the piggyback can only modify the signal coming from the standard ecu.



if you do a complete standalone with wideband feedback then there is no fighting between systems as you have ONE feedback and ONE fuel command.
 

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Discussion Starter #34 (Edited)
hes right. and thats what i forced the pcv to do to get a closer base (since the yuminashi one was so rich in the closed loops) for the wb2 to tune off of. now that its written, its back to the pcv/wb2 controlling it. Most people have issues because they don't understand whats actually going on or how to tune a motor.


Keep in mind, i'm tuning the closed loop here in the last effort i made. the open loop has been great, zero issues. I'm also working with what i had. could i get a standalone? sure. no problem. But unlike the master parts changers always looking for the 'magic bullet bolt on', I can work with what i have, and i am, and its working just fine. With -zero- blowups since the bike was new. so... i'm good there. But, i like to tune motors, i dig it, its my hobby. I could have stuffed an fcr carb on my bike 3 years ago, (its still siting in the box with an intake on my shelf) and done away with all this, but I went a different way for fun.


cali.jpg
 

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Discussion Starter #36
no, the real answer is that, it works. IF like me, you had all this stuff already, instead of just replacing all of it, you can just add a 75 dollar ecu and get the results. thats who this thread is really for, im not saying to do this from scratch.
IF the current standalones were available when i started i would have gone the other way. ...actually, i did, i had the 1st gen api ecu from yuminashi and it was fucking garbage. No wide-band capability, was terrible. and it would lose the maps. But at the time it was the only one available.
 

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I understand. There's a simple solution for me... a product I don't need to mess around with.



I'm surprised that no one makes make a stand alone module that will self learn to run from 13.2 to 12.6 A/F. You're obviously not the only one with this issue.
Just look at all the trouble you're going through trying to get your engine to run without self destructing.
Seems like a great business opportunity for someone to fill that need.
First of all, tinkering and problem solving are what make this fun for me. Secondly, that absolutely exists. I'm simply not dropping $700 on it.
 

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Discussion Starter #38
i never bought this bike to not mess with it. I have stockers for push button and go. also, i'm never ever worried about 'holding my motor together', and it runs really well, pretty much always has. I actually know what i'm doing here.... you're right tooter, you don't need it. I never said it was for you or most on here, this WHOLE THREAD had to do with legacy owners of the pcv and wb2, and finding a cheap ecu alternative. also, fwiw, the WB2 is plug and play to set the afr in the closed loop at 13.0 on a stock ecu.
 

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the guys having problems aren't running full standalone with wideband feedback.


they are running piggyback with an ecu that uses narrowband feedback, when their piggyback device uses wideband feedback. this creates a feud between the two fuel controllers. when the wideband piggy back tuner adds fuel the narrowband standard ecu sees it and pulls fuel out of the base table, this results in the overall fuel being reduced as the piggyback can only modify the signal coming from the standard ecu.



if you do a complete standalone with wideband feedback then there is no fighting between systems as you have ONE feedback and ONE fuel command.
Really good information there ^^^^^, we in the Bay area came to the same conclusion
 
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