'08> TE EFI: closed loop vs. open loop

[Doriak]

Okay, I'll go first here. My '05 Sherco 4.5i used an open loop Magneti-Marelli efi and ran great but seemed a bit "rich", I believe due to open loop efi. My new '08 TE450 has Mikuni efi and is currently in stock closed loop configuration (O2 sensor installed). I will be installing some or all of the power-up kit soon and have a question for any EFI experts here;

When you remove the O2 sensor (aka lambda probe) and install the kit's O2 plug connector, this changes the efi to an open loop and the O2 wire plug connector activates a fixed ECU map?

In closed loop, the EFI receives info from the TPS and O2 sensor and adjusts fuel injection duration accordingly for most efficient running - performance, fuel economy, emissions etc. This allows the EFI to remain "flexible" and compensate somewhat for altitude (air density) effectively "re-jetting" the fuel/air mixture as you ride (my preference) and a big reason IMO to have EFI in the first place.

In open loop, the EFI obviously gets no feedback from the removed O2 sensor, and the O2 plug connector locks the EFI into a pre-determined "race" map (non-compensating) - it runs the same no matter what - rich with maximum power and resultant poorer fuel economy.

My plan is to install the power-up Arrow muffler and spark arrestor insert, but leave the O2 sensor installed so the EFI can work at 100% capability. The bike has plenty of boost in stock trim for my riding (DS & trail) so I think the Arrow with the O2 sensor installed will be all I need to ditch the CAT, increase power and still get the full benefits from the closed loop EFI.

Am I on the right track here?

 

[jlk_250]

"Open loop" and "closed loop" is a little confusing here. Here's a link to some good info about different types of FI. Ours is a "speed density" type as described in this link.

http://www.carcraft.com/techarticles/electronic_fuel_injection/index.html

One important point here is that the barometric pressure and air temperature sensors are used for altitude/temperature changes whether or not the O2 sensor is disabled. You can try using the O2 sensor with the power-up exhaust but the stock fuel map is based on stock exhaust components so a free-flowing exhaust might not work so well. And it might not work so well even with the stock exhaust, depending on what stock FI parameters are on your particular bike--the 2008 bikes were not all delivered the same way. Try it and see for yourself. If it works for you, great. If not, you might be able to use the iBeat software to make it work for you. And if that doesn't work, you can disable the O2 sensor and adjust the fuel delivery using a Dynojet Power Commander. People have done just what you've suggested and I recall at least a couple of people who found that it worked well enough. Maybe someone will pipe up with more info. Or read the old threads here and on Thumpertalk.

 

[Doriak]

"Open loop" and "closed loop" is a little confusing here. Here's a link to some good info about different types of FI. Ours is a "speed density" type as described in this link.

http://www.carcraft.com/techarticles/electronic_fuel_injection/index.html

One important point here is that the barometric pressure and air temperature sensors are used for altitude/temperature changes whether or not the O2 sensor is disabled. You can try using the O2 sensor with the power-up exhaust but the stock fuel map is based on stock exhaust components so a free-flowing exhaust might not work so well. And it might not work so well even with the stock exhaust, depending on what stock FI parameters are on your particular bike--the 2008 bikes were not all delivered the same way. Try it and see for yourself. If it works for you, great. If not, you might be able to use the iBeat software to make it work for you. And if that doesn't work, you can disable the O2 sensor and adjust the fuel delivery using a Dynojet Power Commander. People have done just what you've suggested and I recall at least a couple of people who found that it worked well enough. Maybe someone will pipe up with more info. Or read the old threads here and on Thumpertalk.

Thanks heaps for the reply and info. So can/should "speed density type" be, for the sake of discussion, categorized under "closed" or "open" loop since everyone here seems to refer to these two types when discussing FI?

"And it might not work so well even with the stock exhaust, depending on what stock FI parameters are on your particular bike--the 2008 bikes were not all delivered the same way."

Can you expand on this statement?

Does the Husky/Mikuni FI use an intake sensor to measure air density/temp? Doesn't this work in concert with the O2 sensor in closed loop? Can anyone offer a component description of the Husky/Mikuni FI system? So far I have RPM, O2, TPS and coolant temp.

I have just read every post in Creeper's original thread in Technical>Common>Info '08 Husky race kit which morphed into an EFI discussion pseudo hijack. So do we continue that discussion here in the proper forum titled EFI/carb that Coffee created or move over to Tech>Common where a lot of discussion has already taken place?

I'm an EFI novice and want to learn about it relative to my '08 TE450 - at least a fundamental working knowledge. Not sure I want to be diving into ibeat/powercommander/etc etc "tuning". But I might have to

Thanks!

 

[Coffee]

I have just read every post in Creeper's original thread in Technical>Common>Info '08 Husky race kit which morphed into an EFI discussion pseudo hijack. So do we continue that discussion here in the proper forum titled EFI/carb that Coffee created or move over to Tech>Common where a lot of discussion has already taken place?

The harder I work the more I fall behind. I'd appreciate the newer EFI posts in here and I'll start collecting up the EFI threads in other areas soon and putting them in here. Unfortunately "EFI" is 3 letters and the search function needs at least 4 characters to find anything.

Maybe I'll resort to the google site search.

 

[jlk_250]

Thanks heaps for the reply and info. So can/should "speed density type" be, for the sake of discussion, categorized under "closed" or "open" loop since everyone here seems to refer to these two types when discussing FI?

It seems that people refer to EFI with O2 sensor feedback as "closed loop" and EFI without O2 sensor feedback as "open loop". I try not to use this terminology at all because it's not clear.

"And it might not work so well even with the stock exhaust, depending on what stock FI parameters are on your particular bike--the 2008 bikes were not all delivered the same way."

Can you expand on this statement?

There are some tuning parameters in the ECU that can be set with the ibeat software. Husqvarna did not ship all bikes with the same parameters. Then some dealers updated the parameters using ibeat and some did not. And there are rumors of a new ECU that requires a different ibeat system for 2009 models that some 2008 bikes may have received. The result is that what works on one bike may not work on another.

Most bikes seem to run poorly as delivered. Mine was bad enough that I felt unsafe riding it on the street until I installed the power-up kit. Every magazine review I've read specifically stated that the bikes were provided for review with the O2 sensor disabled so I think Husqvarna put their effort into passing the tests to get certified for street use and stopped there.

Does the Husky/Mikuni FI use an intake sensor to measure air density/temp? Doesn't this work in concert with the O2 sensor in closed loop? Can anyone offer a component description of the Husky/Mikuni FI system? So far I have RPM, O2, TPS and coolant temp.

Do a google search for "ibeat" and "mikuni". Mikuni put out a brief description of how their EFI system works and there are threads here and there about how people have been figuring it out. The EFI system has sensors for barometric pressure, intake air temperature, throttle position, RPM and the O2/Lambda sensor. There is a coolant temperature sensor but I don't know if the EFI system uses it or not. I've read everything I can find and do not know the details of exactly how it it is implemented and exactly what ibeat does. Nobody at Husqvarna has provided the details and the rest of us are making educated guesses.

 

[Coffee]

Maybe I'll resort to the google site search.

This is indeed working!

efi site:cafehusky.com

Sorting through 330 threads now... it may be a little while.

 

[jellyrug]

FI Stock

I have the 610 and still have it 100% stock, have not touched the fuel injection.

My dealer told me that the difference with power-up on the 450 and 510 is huge, but with the 610 it only makes a small difference. Any experience from the 610 riders?

I really cannot complain about mine, my last fill-up I got 85 miles on 1 1/2 gallons, riding a combination of paved and unpaved roads, with some mean twisties, so I used 4th, 5th sand 6th gears, most of the way. That's almost 57 miles to the gallon.

I also trucked the bike from 400 ft altitude to around 5,000 ft and back and was pleased to find that after the motor warmed up, the FI adjusted itself to perfect idling and behavior. I travel a lot, so my bike is sometimes down for 8 weeks and starting even in the cold is almost immediate.

It will be good to hear from the TE610EI riders with power up kits if it was really worth it?

 

[Doriak]

The harder I work the more I fall behind. I'd appreciate the newer EFI posts in here and I'll start collecting up the EFI threads in other areas soon and putting them in here. Unfortunately "EFI" is 3 letters and the search function needs at least 4 characters to find anything.

Maybe I'll resort to the google site search.

Thanks Coffee for reigning all of this EFI stuff in! I just finished reading all of it - phew! My head hurts rofessor:
I've searched TTalk etc for EFI info and it gets pretty tedious. Hopefully CafeHusky will become a one-stop-shop for lots of good, Husky-specific information.

 

[Doriak]

There are some tuning parameters in the ECU that can be set with the ibeat software. Husqvarna did not ship all bikes with the same parameters. Then some dealers updated the parameters using ibeat and some did not. And there are rumors of a new ECU that requires a different ibeat system for 2009 models that some 2008 bikes may have received. The result is that what works on one bike may not work on another.

Most bikes seem to run poorly as delivered. Mine was bad enough that I felt unsafe riding it on the street until I installed the power-up kit. Every magazine review I've read specifically stated that the bikes were provided for review with the O2 sensor disabled so I think Husqvarna put their effort into passing the tests to get certified for street use and stopped there.

Do a google search for "ibeat" and "mikuni". Mikuni put out a brief description of how their EFI system works and there are threads here and there about how people have been figuring it out. The EFI system has sensors for barometric pressure, intake air temperature, throttle position, RPM and the O2/Lambda sensor. There is a coolant temperature sensor but I don't know if the EFI system uses it or not. I've read everything I can find and do not know the details of exactly how it it is implemented and exactly what ibeat does. Nobody at Husqvarna has provided the details and the rest of us are making educated guesses.

Thanks for the replies jlk. Seems like the more I/we look into this, the more questions arise! Like you say, due to significant lack of info from Husqvarna it is a bit of a guessing game among those here with EFI training/experience - with the occassional, helpful tidbit from a dealer along the way. Trying to piece it all together and extract some meaningful (for me anyway) info.

My hat's off to everyone here who's expended the time and effort on the subject

For starters, I'll contact the dealer I bought the bike from to see what/if any ECU/EFI updates were performed prior to me taking delivery of my '08 TE450 (none would be my guess). I'll be stopping by my local dealer (Tasky's) for additional info on what they are doing to these bikes, what they know etc. I'll probably end up experimenting with the power-up kit before I dive into tweaking the electronics (and possibly have some concrete info regarding any compatible '09 updates...)

Thanks.

 

[ioneater]

Thanks for the replies jlk. Seems like the more I/we look into this, the more questions arise! Like you say, due to significant lack of info from Husqvarna it is a bit of a guessing game among those here with EFI training/experience - with the occassional, helpful tidbit from a dealer along the way. Trying to piece it all together and extract some meaningful (for me anyway) info.

My hat's off to everyone here who's expended the time and effort on the subject

For starters, I'll contact the dealer I bought the bike from to see what/if any ECU/EFI updates were performed prior to me taking delivery of my '08 TE450 (none would be my guess). I'll be stopping by my local dealer (Tasky's) for additional info on what they are doing to these bikes, what they know etc. I'll probably end up experimenting with the power-up kit before I dive into tweaking the electronics (and possibly have some concrete info regarding any compatible '09 updates...)

Thanks.

You'll be in good hands with Jeff and crew. They sell a LOT of Husky's so hopefully will be able to anwer pretty much anything you can throw at 'em.

 

[ramz]

I've done some digging into the 2008 Workshop Manuals for the TE 250/450/510 and the TE610 to look for information about sensors in the fuel injection system. I extracted, edited, and added this information to my TE Tuning page: TE tuning

There is more information to be distilled and I'll update my tuning page as I get the work done.

 

[Doriak]

I've done some digging into the 2008 Workshop Manuals for the TE 250/450/510 and the TE610 to look for information about sensors in the fuel injection system. I extracted, edited, and added this information to my TE Tuning page: TE tuning

There is more information to be distilled and I'll update my tuning page as I get the work done.

Well done ramz. Good information! Just last evening I studied my '08 TE450 owners manual elec scheme and noted the same EFI components.

I see that items #24 TPS, #32 air temp sensor and #34 (air) pressure sensor all make up item #40 M.A.Q.S (modularized air quantity sensor)

Look forward to more info.

 

[Doriak]

I'll be stopping by my local dealer (Tasky's) for additional info on what they are doing to these bikes, what they know etc. I'll probably end up experimenting with the power-up kit before I dive into tweaking the electronics (and possibly have some concrete info regarding any compatible '09 updates...)

Like ioneater et al have said, Jeff at Tasky's knows his stuff! He filled me in on my '08 TE450; set-up tips, power up info etc.

Anyway, I've now ridden my bike with ALL of the power up components installed and as everyone has said, it runs great! No more jerky low speed throttle, spitting and popping, and virtually eliminated flame-outs. Starts and idles much better - smooth and consistent. Definitely a bit richer with the O2 removed. Have not tweaked the factory ECU/EFI mapping. Running it as-delivered which Jeff said was fine. Also, for trail riding, going from the stock 47T rear sprocket to a 50T was a big improvement too.

So I'm really happy with how the bike runs. The only thing I haven't been able to do yet is determine, for me and my riding, what kind of fuel economy I'm getting/going to get? I'd like a bigger tank but as oft- discussed already here waiting for a better solution other than IMS. Which means I might be waiting for awhile - or end up with an IMS

Cheers