EFIE Experiences

Nice write up.

You had me on the edge of my seat thinking you were going to bite the bullet and weld-er-up! I'm diggin that print in your garage directly in front of your Z in the first shot.

Bummer that our open/closed ECU communication nonsense isn't as straightforward as the Grom guys. I read through that thread you linked and almost bought an EFIE before I remembered "this isn't our bike... this isn't actually relevant."

What would it take to augment your wideband to log AFRs like the grom thread with the bazzaz? That seems like it would be a very useful tool for this process. Start a go-fund-me to buy the crap and I'll support you. XD

OK gents minor update:

Greg- Thanks for link. I actually read that same article last night. Lots of good info in there.

Ando - Some type of standalone hardware to log to honestly I'm not sure what it would take... and I would only have AFRs, not throttle position or RPM so not sure how useful it would be.

So far today before work: I confirmed continuity from all (4) O2 sensor wires back to end of harness right before it plugs into ECU. I also confirmed that the ECU is sending voltage to O2 sensor (bias voltage) which is why I had signal on the voltmeter over 0.9 volts and why Kawi tells you to pull voltage across the pos and neg (black and grey) wires, and not just black to universal ground. When in doubt follow the directions I guess.

Today after work: I had ECU unplugged all day. I left EFIE connected but zeroed the offset (Hopefully this is actually zeroing and not the "I washed my bike today and it feels like I gained 15% HP). Fired the bike up and went for a ride. AFRs appear to be normal, not the crazy swings I had first time out with EFIE. I believe this process DID clear out the fuel trims. AFRs at idle, WOT, and above 8kish adjusted during the ride. Going to let it cool off then go out again. I really want that CEL to turn off, then I will clear fuel trims, set EFIE up for a conservative 0.100 V, and take a ride to check AFRs.

At this point I kind of hope that open loop is not effected by closed loop trims (although my guess from the first ride here is that they are). The bike actually runs pig rich at WOT. Beginning of my ride today I was seeing 11.5! It was getting closer to 12.0 as the short term trims were getting learned. Fear is that if the map gets shifted with the EFIE the already rich open loop numbers will get even richer.

The plus side, however, is that if the injectors are capable of pumping enough fuel to generate an 11.5:1 AFR then it's looking good that the stock ECU can handle intake and exhaust... but don't quote me on that yet, that'll be Phase III.

Also, the O2 heater circuit is energized when the key is on... If ECU is monitoring the heater circuit when key is on but bike is off, that could be what caused it to throw the code.

Ando - by the way that print... my sister picked it up for me about 15 years ago at a salvation army!

The only thing I can think of as to why this isn't working might be where they talk about the Titanium sensors giving a resistance. Is it possible this is the type of sensor that we have in the Z?

I will still probably weld up a bung for my AFR meter, but not likely this season since the season is basically over. 50 degrees and rain all day, barely got above 60 the last 2 days... I'm afraid Winter is here and will stay through to about May. And the AFR meter might depend on what I do with my KAYO, if there is room, that gauge will be going in there, it's carbed so it would make jetting much nicer than simply relying on temperature estimates for jet sizes. Need to make a new display area once I get my shift light working, shift light has a tacho in it so I can remove the big in-accurate tach and put in some aluminum. Have to see how things go. Need to make room for a battery in the KAYO as well. Also need some switches to turn on the power from battery, and turn on the cameras for recording.

For those that have no idea what I'm talking about, here are the two posts on the shift light:
Shift light and tachometer - part1
Shift light part 2

Greg - I thought about the different type of plug. No, we don't have titanium... Kawi gives the testing spec in voltage not ohms. Also, after just coming home from 2nd ride, I stripped some of the gray wire and measured voltage across grey to black with the bike running... saw oscillation between 0.1 and 0.9 V, so that one's put to bed... bias voltage confirmed! Bias is about 0.5 V, so the 0.250V correction with the EFIE shouldn't cause an out of range code. And yeah, wideband makes jetting way easier with carbs... especially the idle mixture screws. That's actually why I have this thing!

Shift light project looks really interesting!

Ando - LOL at communism being nice... in theory.

2nd run after "reset" in effort to clear CEL. AFRs are getting much closer now to my first measurement. The power off either clears the trims for sure or this is an insane case of placebo effect.

I'm getting a much better idea of how the ECU adjusts AFR based on throttle position and RPM combo... honestly it really isn't too bad. My only major gripe, after determining that there is basically zero risk of running lean (stock) at WOT is the lean surges you get occasionally around 5-6k RPM with throttle just cracked. More to come.

OK boys we have proof of concept.

CEL was out today so I dialed up EFIE to a 0.125 V offset and went for a ride. This was without clearing any trims.

I noticed that cracked throttle cruising AFR dropped and I was seeing 13.7 and 13.8 for the first time. The AFRs swing around, stock is like 14.4 +/- 0.4. With this offset I got to maybe a 14.2 +/- 0.5. There are couple things coming into play here.

First, trims were not reset and the ECU most likely needs more time to re-learn. I only went for maybe a 6 mile ride.

Second, as narrow band O2s get farther away from an AFR of 14.7 accuracy drops of QUICKLY and a smaller change in voltage can correspond to a larger change in AFR. This doesn't worry me too much... AFR on carbs swings much wider than what I was seeing on my test ride today. The average AFR drops, but the "swing" could potentially grow with an aggressive offset.

So I went back to the garage, and with the bike still running, turned up the voltage offset while I watched the idle AFR drop. I got it down to around 13.3 and went for a ride. I needed an offset of 0.360 V to get there. Promptly threw code 33: bad O2 sensor. So I took it a bit too far. The offset must have sent voltage from the O2 out of range.

Rode home dialed the offset back to 0.250 and disconnected the battery. I'll take it out again tomorrow with no trims stored in ECU and see how it runs.

I will say this... even with just the 0.125 V offset... I was hunting around for lean surge on cracked throttle between 5-7 krpm and couldn't find it, so I'm optimistic. Still need to see how open loop is affected.

I have a zoom loop and a K&N filter for DIY intake coming, hoping to have both here by end of day Friday, and weather is looking good this weekend. So if the parts arrive on time the goal by Sunday night is to post up confirmation that stock ECU can handle exhaust and intake, and maybe even some tuning info on the EFIE.

One thing I think that may come into play, is that as we tune EFIE and get away from 14.7 AFR, because of the loss of accuracy, what may work on one bike may not work 100% on another, even with identical mods, due to accuracy tolerances of narrow band O2s. That's pure speculation on my part, but from what I read, and since we're pretty much asking the narrow band to shift lamda and almost act as a wideband, I think some variability between different O2 sensors can be expected.

Side note- apparently having the bike on (not running) with O2 disconnected will throw the O2 heater circuit code. Heater circuit is energized when key is turned on, and it is grounded through the ECU. I read that in some vehicles the ECU can "pulse" the ground to turn on or off the heater circuit. The code gets thrown if resistance (ohms) is out of spec, or if there is a short in the circuit, or if the circuit is open, which is the case when the O2 is disconnected.

I'm guessing you will end up somewhere between 0.125 and 0.250 offset on the current intake and pipe. all bets are off on new intake and pipe, but you might get lucky.

Greg- You're probably right. Grom guys said 0.250 was about the limit.

Here is my install write up for anyone interested:

https://www.pdfhost.net/index.php?Action=Download&File=d2f4366e2f4f519630bf5646f69faf98

Appreciate your write-ups. You must be an engineer when you aren't hooning around the coast on mini bikes. This is sounding more and more promising.

OT: If it weren't a heavy/awkward PITA to ship I'd like to try your Kaw'ee mod'd exhaust. I've been trying to think of ways to make a non-permanent hole (not technically my bike) in the left side of chamber #1.

LOL Ando at "must be an engineer".

I have a degree in jazz performance on violin and trombone. I freelance playing weddings and private parties and have a little computer business on the side. I work in construction as a day job. I just really like tinkering!

As for the Kaw'ee mod... do it! For safety! It really does sound a lot better than stock. I didn't drill hole into the chamber, just used channel locks like Kaw'ee recommended to pull out the tube at the back of the exhaust. It pretty much bypasses the 2nd cat. Only thing is you need to loose that silver exhaust tip type thing. Guess you could tack it back on. Anything beats the sewing machine sound though IMO!

Whelp! You know what they say about as suming. -_-

Despite it being heavy I actually like the OEM vanity exhaust exit, which is why I want to make the hole on the other side. From what I remember the exhaust goes through both cats before hitting expansion/baffling chambers. Someone (probably kaw'ee) drew a crude representation of the inside of the OEM muffler.

The inner exhaust "tip" goes through chamber #1 at the very back of the can and connects to chamber #3. Removing it allows gas and sound to skip 2/3 chambers.

And yeah, I'd probably just do it... but it's not technically my bike and wifey won't even let me plastidip it purple, I imagine she'd be pissed if I tripled the volume without consulting her!

(Ugh, I gotta stop derailing topics. I'm interested to hear how the bike feels with your new mods, be sure to show off your DIY intake!)

Delete / off topic

Hey Kaw'ee, that's nearly exactly what I was thinking! Not sure on efficacy on a vibey bike though. Maybe the exhaust is isolated enough.

Maybe some high temp RTV when you install the plug to help seal it up.

I'm starting to err on the side of "ask forgiveness" and do it over the winter.

"Yeah, it always sounded like that..."

Hey @MrEvilpirate, sounds like you had a big weekend with intake and exhaust.

In summary from other threads:

You're too feckin' old, the Zoom is too loud for you... So is your pod filter...

Suck/Blow mods completed, ears plugged, and butt dyno calibrated. Result? More power, AFRs happy. Success!!!

So the EFIE is a good idea for intake/exhaust simpletons who want to pinch pennies and keep their engine happy. Right?

I appreciated your observation that with just the exhaust and the stock airbox very little power improvement is made, but consequently you also aren't going to have dangerous lean conditions because the intake is still so restrictive. I am curious if the opposite is also true.

Ando I had a great post and lost it. So I've taken a couple days and I'll post complete findings soon. Long story short intake and exhaust lean out the mix in open loop. Still fairly safe but bike runs much better using EFIE mod, target voltage for me is 0.195 V but YMMV... EFIE is a good idea. Full results soon...

I have numbers stock, stock and EFIE, intake only, EFIE and intake, EFIE intake and exhaust.

Unplug the black wire which is the signal wire on the O2 to keep the ECU running in open loop.(?) I'll try it.

Here it is long overdue, my findings after widebanding the Z and messing around with O2 signal voltage.

First some corrections to my first wideband readings post as I have spent a lot more time watching the gauge and know more about how the bike runs.
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Stock the bike cold idles at 13 and warms up to 14.6 +/- 0.3. So as the ECU adjusts the AFR based on O2 readings it oscillates between 14.3 to 14.9. One thing I noticed is after you blip the throttle or get off the gas AFR at idle drops to about 13.8, then slowly climbs up to 14.6 over about 15 seconds. I think they do this to keep the mix rich in case you start again quickly... richer mix can make up for no spark advance.

Cracked Throttle cruising is same as idle (both closed loop) around 14.6. "Dig in" a bit, maybe 3/4 throttle it drops to 13.3ish. Any revs, regardless of throttle position, over around 7k and AFR drops to 13.3ish. WOT gives you AFR of 12. So the bike runs rich stock, except at cracked cruising, where it can get a touch lean and in my experience cause some surging at mid RPMs.
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Enter EFIE. I ended up with a voltage offset around -0.195 v.

After learning some trims, cold idle is now 12.8. Warm idle does the same raise up over about 15 seconds. But with EFIE correction it is about 13.1 (right after a blip) and settles around 14.2. This eliminates the surging I was complaining about. Cruise/cracked thottle is in closed loop... O2 signal is offset, so AFR for this range is same as idle, about 14.2.

3/4 throttle and over 7k RPMs about 12.9 and WOT is 11.8-12.0. So EFIE's modulated signal caused fuel trims to be learned as richer than without EFIE, this translated into richer open loop settings after the ECU learned the trims. PS all these numbers I'm giving you are after starting and stopping the bike many times (cold starts) and running about 100 miles at each setting.
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With EFIE and Intake:

Cold idle back up to 13... intake leaned EFIE mix from 12.8 back up to 13 cold idle (open loop)

Warm idle (closed loop) the same as just EFIE at 14.2 (with 15 second dip to 13.1 after blipping throttle)... ECU can handle intake and richen mix to get to it's target AFR no problem... remember EFIE is RICHENING the mix, so if ECU can hit target with EFIE, stock ECU can handle intake in closed loop without it as well.

Cruise/cracked throttle is closed loop, so same as just EFIE 14.2.

3/4 throttle or above 7k 12.9 - 13.2. So even though ECU learned trims, when applied ECU does not get stock AFR with intake at this throttle position. But this is safe range. Remember... EFIE is used in this example and is making the ECU learn trims that are richer than would be without it. So even though this is open loop, by using the EFIE in closed loop more extreme fuel trims (richer) have been learned.

WOT 12.2 - 12.5. Again intake is shown to lean the mix.
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EFIE, intake, and pipe

Cold Idle - 13 (note pipe did not lean the mix more than just intake. These parts flow more air the higher the RPM... so at idle they flow a little more than stock, but when ripping hi RPMs they flow a lot more than stock... part of the reason why learned fuel trims can't accurately maintain stock AFRs at higher RPMs or more open throttle positions... because the trims are learned under closed loop conditions, where performance parts perform closer to stock, in terms of how much air they let flow through).

Warm idle - 13.1 (after blip) up to 14.2.
Cracked Thottle/Cruise - 14.2. This proves stock ECU can handle intake and exhaust and provide stock AFR levels during closed loop operation. Again EFIE is used in this example. Without it the ECU wouldn't need to send as much fuel, so stock is the same thing you will get stock AFRs in closed loop.

3/4 Throttle and over 7k rpm- about 13.3. Leaned out a touch more than with just intake. Still safe. Again with EFIE.

WOT - 12.4 - 12.7. So check this out. Honestly I think it pulls harder closer to 13 than 12.
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FINALLY - NO EFIE, STOCK ECU, INTAKE and EXHAUST:

Cold Idle 13.3
Warm Idle (after 15 second rise) and cruise/cracked throttle 14.6
3/4 and above 7k - 13.9
WOT - 13.3
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Thoughts

For stock bike without fuel controller and adding intake and exhaust, it looks generally safe, with the following caveat:
Richer mixes run cooler. Kawi set this thing to run rich at WOT, partly I believe to control head temps. I don't know enough about AFRs to tell you if it is safe to run this type of motor for long periods of time WOT at an AFR of 13.3. It seems OK. 13.9 at 3/4 seems a touch high though.

EFIE seems like a good cheap add to the bike to get more fuel flowing if you want to run these mods.

Personally I would run it even on a stock bike, especially if the surging at mid RPMs when rolling on from cracked throttle bugs you.

For Kaw'ee and guys running O2 deletes, be advised that the "closed" loop without the O2 tends to run lean. I was seeing numbers over 15. This was on stock bike. I didn't take readings with mods. So at idle or cracked throttle/cruise, without O2, you are lean. It does richen at 3/4 and WOT compared to stock. I suppose that cracked throttle AFR being lean MAY be acceptable because there is minimal load on the engine. When you decelerate the mix leans out to the point where it can't be measured on the gauge... but I personally would not be comfortable. Kaw'ee... I think you mentioned your idle temps went up when you deleted the O2. This is why.

Personally If I were you guys with no O2 I'd just weld the bung on and call it a day.

It's late I couldn't sleep and have been wanting to get this out.. I didn't proof it and it is a wall of text. Hope you can get something from it. Happy to answer any questions to the best of my ability.

Think I'm ready to turn the page on this one and put the wideband away. Now we know.

In general, the WOT seems very much too rich. Dipping down into 11.x will lower your power. Sounds like you have discovered a good combination of things and the max power up closer to 13 would be best for alcohol free fuel. Throw in 15% ethanol and you'll want to be down around 12.4.

I've read through this a couple times and know more now than when I started reading but it's a lot of info for me. The general take away I got was the stock ecu can and will adjust to an aftermarket intake. The stock ecu can and will also adjust to and aftermarket intake and exhaust, but that's asking a lot of it and probably not the best thing to do. The stock ecu with no aftermarket parts is how Kawasaki intended but could be improved with installing EFIE but to really know what the EFIE is doing you have to install a wideband by welding a port onto the exhaust pipe.

I personally would like to put aftermarket exhaust on just for looks and sound. After reading this I feel I could do so without any additional items ie Bazzaz, EFIE, Hoedar ECU.

TBS- you pretty much got it bud. Run that pipe and don't look back. Bike will be fine.

Next spring I'm going to put my stock airbox back on and try running with just the pipe. But I will personally keep EFIE.

Even in stock configuration, my experience is that EFIE improves the bike's fueling... but my results show you don't need it to keep AFR in safe range.

Keep the shiny side up brah!!! lol

Now back to all the exhaust threads. =)

I think going from 8hp to 10hp would be something you would really notice in the seat of the pants.

Just a heads up from the grom forum this week.
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Quote Originally Posted by asume
Note to all EFIE installers.
You'll have to keep adjusting the device depending on how much you ride. The vibrations tend to readjust the device.

Quote Originally Posted by farkas
Good advice.. I noticed this too.
I ended up using velcro tape so that I can take it on and off of the battery tray under the seat for easy adjustments.