Closed-loop fuel enrichment
#42
I appreciate the offer, c2pid! The project certainly hasn't been cheap, as you can tell from the picture below. Let me get a successful road-test of a week or more under my belt and I'll let you know.
Update: 8/17/10
All of my new electronics gear arrived last Friday and I spent most of the weekend playing around with the module.
(Note the new dual-channel linear power supply on the left and the digital oscilloscope in the middle)
Up until this afternoon, all of the prototyping/testing has been done at my workbench where I had a clean power-supply and very isolated interference. I was getting great results from the controller at my bench, but once I did my first test of the unit in the car, my results were all over the place again. I made a couple more adjustments to both the hardware and software and was finally able to get stable results in the vehicle.
The next step is to connect the rest of the modules and take it for a test drive. I've been extremely busy with work lately so I'm not exactly sure when that will be, but like always, I'll keep you guys posted.
Update: 8/17/10
All of my new electronics gear arrived last Friday and I spent most of the weekend playing around with the module.
(Note the new dual-channel linear power supply on the left and the digital oscilloscope in the middle)
Up until this afternoon, all of the prototyping/testing has been done at my workbench where I had a clean power-supply and very isolated interference. I was getting great results from the controller at my bench, but once I did my first test of the unit in the car, my results were all over the place again. I made a couple more adjustments to both the hardware and software and was finally able to get stable results in the vehicle.
The next step is to connect the rest of the modules and take it for a test drive. I've been extremely busy with work lately so I'm not exactly sure when that will be, but like always, I'll keep you guys posted.
#46
Chapter Leader (Southern Region)
bmeyer.. what type of PIC microcontrollers are you using?
Have you thought about selling your code instead of pre programmed PIC's or kits?
Last edited by Majofo; 08-17-2010 at 01:59 PM.
#47
I'm using PIC12 series microcontrollers for the time being.
The problem with selling just the code is that I want to keep it simple for the guys that don't have the proper equipment to build and test their circuits before installing them. If you don't do everything EXACTLY right, you'll have nothing but troubles with the module and potentially hurt your engine. And the last thing I want to do is support guys that don't have the know-how to properly build and test a circuit and get blamed for blown engines. :/
I should probably get a poll going to see what people want and just how many are ready to buy one before I get too excited about *how* I want to sell them.
The problem with selling just the code is that I want to keep it simple for the guys that don't have the proper equipment to build and test their circuits before installing them. If you don't do everything EXACTLY right, you'll have nothing but troubles with the module and potentially hurt your engine. And the last thing I want to do is support guys that don't have the know-how to properly build and test a circuit and get blamed for blown engines. :/
I should probably get a poll going to see what people want and just how many are ready to buy one before I get too excited about *how* I want to sell them.
#48
Chapter Leader (Southern Region)
Yeah.. I understand. Can you go smaller than the PIC12 or did you choose it to be open ended so you can add more I/O later?
#49
You probably could go smaller than the PIC12 just as long as it has an ADC and I2C built-in - which means you would need a minimum of 5-pins (VCC, VDD, SCL, SDA and an analog input). These are only 8-pin chips so it's not like I'm using ATMega328's with 28+ pins or anything. I just had a couple of these laying around and they were cheap so I decided to start with them.
#50
Chapter Leader (Southern Region)
#51
Former Sponsor
Very nice! What scope is that? I've been looking into getting a new one. Let me know if you need help designing a low noise power supply. I've done a few projects with PICs and AVRs for auto applications. Cars are a very noisy environment.
#52
@Richie
It's a Rigol DS1052E 2-ch 50MHz scope that is hack-able up to 100MHz. It had rave reviews and was great bang-for-the-buck. It's got a great feature-set and is dead-simple to use.
Links:
I'd definitely be interested in hearing what you know about power supplies. Cars are by far the worst electrical environment I've ever worked with. Shoot me a PM whenever you get a chance.
It's a Rigol DS1052E 2-ch 50MHz scope that is hack-able up to 100MHz. It had rave reviews and was great bang-for-the-buck. It's got a great feature-set and is dead-simple to use.
Links:
Full review
http://www.youtube.com/watch?v=kdjpbWLi7UI
Teardown
http://www.youtube.com/watch?v=sO5iGwHpmHc
100MHz mod
http://www.youtube.com/watch?v=LnhXfVYWYXE
http://www.youtube.com/watch?v=kdjpbWLi7UI
Teardown
http://www.youtube.com/watch?v=sO5iGwHpmHc
100MHz mod
http://www.youtube.com/watch?v=LnhXfVYWYXE
I'd definitely be interested in hearing what you know about power supplies. Cars are by far the worst electrical environment I've ever worked with. Shoot me a PM whenever you get a chance.
#53
Former Sponsor
Oh man I am a sucker for hardware hacks. I'll pick one up when cash isn't so tight. I built a electronic boost controller for my senior design project. We were getting some crazy erratic boost spikes from noise reseting the micro.
#54
Chapter Leader (Southern Region)
Richie are you an EE?
#55
Team Owner
I love these threads that are over my head. It's nice to (try) learn something new. Thanks guys.
#56
Chapter Leader (Southern Region)
#58
im rather new to the acura world but not to the tuning world- so explain to me why you need to tune your closed loop fueling map- as soon as the car enters boost it should automatically switch to open loop which is important- riding around town using light throttle is good to keep a 14.7 af ratio - if its first entering into boost you are getting knock counts most likely your timing in that area needs to be turned down- or you need to adjust your tip in enrichment.
did you ever try unplugging your primary o2 sensors to keep the car in open loop- and tuning the fuel map that way
did you ever try unplugging your primary o2 sensors to keep the car in open loop- and tuning the fuel map that way
#60
Update 8/18/10
Test #1 is complete. The car seems perfectly happy to idle from 14.7:1 - 10.5:1 with the new unit. I need to switch a couple of wires around since my voltages seem to have an inverse effect. After that, I'll drive the car around for a week or so and make sure that no CEL's are triggered.
Test #1 is complete. The car seems perfectly happy to idle from 14.7:1 - 10.5:1 with the new unit. I need to switch a couple of wires around since my voltages seem to have an inverse effect. After that, I'll drive the car around for a week or so and make sure that no CEL's are triggered.
#63
More Updates 8/18/10
I setup the A/F table in the F/IC to correlate a voltage value to a specific A/F ratio, which basically means that you can input a target A/F ratio into a cell in the O2 table and have the car achieve that under closed-loop. After doing so, I have <0.1% variance from the values in the cells to the reading on my LM-2 wideband sensor.
Also, it looks like the final adjustment range widened a bit once the car was fully warmed up. The new range is 10.2:1 - 14.7:1.
I setup the A/F table in the F/IC to correlate a voltage value to a specific A/F ratio, which basically means that you can input a target A/F ratio into a cell in the O2 table and have the car achieve that under closed-loop. After doing so, I have <0.1% variance from the values in the cells to the reading on my LM-2 wideband sensor.
Also, it looks like the final adjustment range widened a bit once the car was fully warmed up. The new range is 10.2:1 - 14.7:1.
Last edited by bmeyer; 08-18-2010 at 10:16 PM.
#65
Turd Polisher
iTrader: (1)
Excellent work bmeyer!
#68
You should be able to look up info on the sensor in the service manual or cross-reference the part number in Google. That should get you pointed in the right direction.
I'll talk to the guys that made the other module and see if they have a narrowband version available and if they can build any custom units for me. The controller that I made doesn't care if it's a narrowband or wideband module that it's controlling so there's no reason it shouldn't work with a different unit.
I'll talk to the guys that made the other module and see if they have a narrowband version available and if they can build any custom units for me. The controller that I made doesn't care if it's a narrowband or wideband module that it's controlling so there's no reason it shouldn't work with a different unit.
#69
Chapter Leader (Southern Region)
#70
Update 8/19/10
One day of driving with the module under my belt. Behaves just as I had hoped and still no CEL. Under part-throttle acceleration, the A/F drops right where it should. The transition happens faster than my LM-2 can keep up with (which is what I saw under open-loop without the module).
One day of driving with the module under my belt. Behaves just as I had hoped and still no CEL. Under part-throttle acceleration, the A/F drops right where it should. The transition happens faster than my LM-2 can keep up with (which is what I saw under open-loop without the module).
#71
Instructor
iTrader: (12)
Update 8/19/10
One day of driving with the module under my belt. Behaves just as I had hoped and still no CEL. Under part-throttle acceleration, the A/F drops right where it should. The transition happens faster than my LM-2 can keep up with (which is what I saw under open-loop without the module).
One day of driving with the module under my belt. Behaves just as I had hoped and still no CEL. Under part-throttle acceleration, the A/F drops right where it should. The transition happens faster than my LM-2 can keep up with (which is what I saw under open-loop without the module).
for sure let me know how i can contribute a little in this r&d. i am seeing the light at the end of the tunnel!
#72
Team Owner
Bmeyer, I hope you realize just how important this is. You just brought TL tuning into the modern world! To those that don't know, he just opened up several doors and solved several problems. There is sooo much tuning that can be done and we'll see turbo and supercharged TLs that drive just like stock.
The really neat thing is turbo spool will be much better with the correct transitional AF.
I know many times the idle is more stable when it's on the rich side, have you noticed any difference in idle stability vs AF such as the dip in rpms when the AC compressor kicks in or intial throttle tip in?
The really neat thing is turbo spool will be much better with the correct transitional AF.
I know many times the idle is more stable when it's on the rich side, have you noticed any difference in idle stability vs AF such as the dip in rpms when the AC compressor kicks in or intial throttle tip in?
#73
@IHC
I definitely do. That's why I've invested so much of my own personal time and resources into the development of this module. That, and I'm really not willing to sacrifice a brand new stroker engine because of only a partial tuning solution.
There have been no changes in idle with the module while the A/C is on because at idle, the module is essentially a pass-through. Meaning that it's not altering the output of the O2 sensors at all. This exact issue is what caused me to pursue this avenue (of real-time adjustment) versus that of simply attempting to add resistors to the F/IC wires and trying to connect them to various I/O wires on the ECU.
I definitely do. That's why I've invested so much of my own personal time and resources into the development of this module. That, and I'm really not willing to sacrifice a brand new stroker engine because of only a partial tuning solution.
There have been no changes in idle with the module while the A/C is on because at idle, the module is essentially a pass-through. Meaning that it's not altering the output of the O2 sensors at all. This exact issue is what caused me to pursue this avenue (of real-time adjustment) versus that of simply attempting to add resistors to the F/IC wires and trying to connect them to various I/O wires on the ECU.
#74
Update 8/20/10
I fiddled around with my fueling in the F/IC this morning. I was actually able to dial back my fuel trims in the fuel table since I'm not fighting the ECU anymore. The result is that the car feels less like a temperamental super-model and more like the civilized luxury car it was intended as. (The car used to stutter frequently in town with less than 20% throttle.)
Oh, and still no CEL's.
I fiddled around with my fueling in the F/IC this morning. I was actually able to dial back my fuel trims in the fuel table since I'm not fighting the ECU anymore. The result is that the car feels less like a temperamental super-model and more like the civilized luxury car it was intended as. (The car used to stutter frequently in town with less than 20% throttle.)
Oh, and still no CEL's.
#78
18psi
iTrader: (7)
Update 8/19/10
One day of driving with the module under my belt. Behaves just as I had hoped and still no CEL. Under part-throttle acceleration, the A/F drops right where it should. The transition happens faster than my LM-2 can keep up with (which is what I saw under open-loop without the module).
One day of driving with the module under my belt. Behaves just as I had hoped and still no CEL. Under part-throttle acceleration, the A/F drops right where it should. The transition happens faster than my LM-2 can keep up with (which is what I saw under open-loop without the module).
Update 8/20/10
I fiddled around with my fueling in the F/IC this morning. I was actually able to dial back my fuel trims in the fuel table since I'm not fighting the ECU anymore. The result is that the car feels less like a temperamental super-model and more like the civilized luxury car it was intended as. (The car used to stutter frequently in town with less than 20% throttle.)
Oh, and still no CEL's.
I fiddled around with my fueling in the F/IC this morning. I was actually able to dial back my fuel trims in the fuel table since I'm not fighting the ECU anymore. The result is that the car feels less like a temperamental super-model and more like the civilized luxury car it was intended as. (The car used to stutter frequently in town with less than 20% throttle.)
Oh, and still no CEL's.
With my car, I always get some hesitation around 3100rpms (regardless of the gear, 5AT) when I accelerate moderately with 1/3-1/2 throttle. The car bogs a little bit but stops jerking after 3300rpms. This is when I have misfires on every cylinder. Ive only had misfires on 3 different occasions in the past 5 weeks since the turbo. Misfires dont happen every time this hestitation/jerking happens.
Also, this problem does not happen under WOT.
Is this hesitation/bogging the feeling of closed-loop to open-loop transition and the FIC taking over? The A/F does not bounce around when this happens. The car just jerks back and forth a little.
Is this a tuning issue that can be corrected with a better tune? Or will this module fix this problem? Other than this problem, I have no other issues with the car.
#79
yo...
bmeyer...I would love to be one of the first guinea pigs for this...I have a accord V6 6MT with a FIC installed...I am planning to run a MP90 supercharger and wanted to be able to fully tune the afr before adding f/i into the equation.
My email is bdbconcepts@gmail.com.
..thanks so much in advance for your help...
My email is bdbconcepts@gmail.com.
..thanks so much in advance for your help...
#80
When does the transition from closed-loop to open-loop actually happen? Peddle to the floor? 50% throttle load? Based on rpms?
With my car, I always get some hesitation around 3100rpms (regardless of the gear, 5AT) when I accelerate moderately with 1/3-1/2 throttle. The car bogs a little bit but stops jerking after 3300rpms. This is when I have misfires on every cylinder. Ive only had misfires on 3 different occasions in the past 5 weeks since the turbo. Misfires dont happen every time this hestitation/jerking happens.
Also, this problem does not happen under WOT.
Is this hesitation/bogging the feeling of closed-loop to open-loop transition and the FIC taking over? The A/F does not bounce around when this happens. The car just jerks back and forth a little.
Is this a tuning issue that can be corrected with a better tune? Or will this module fix this problem? Other than this problem, I have no other issues with the car.
With my car, I always get some hesitation around 3100rpms (regardless of the gear, 5AT) when I accelerate moderately with 1/3-1/2 throttle. The car bogs a little bit but stops jerking after 3300rpms. This is when I have misfires on every cylinder. Ive only had misfires on 3 different occasions in the past 5 weeks since the turbo. Misfires dont happen every time this hestitation/jerking happens.
Also, this problem does not happen under WOT.
Is this hesitation/bogging the feeling of closed-loop to open-loop transition and the FIC taking over? The A/F does not bounce around when this happens. The car just jerks back and forth a little.
Is this a tuning issue that can be corrected with a better tune? Or will this module fix this problem? Other than this problem, I have no other issues with the car.
Does your car actually throw a CEL when it misfires?
I know exactly what you're talking about with that hesitation. Typically what I saw is that my short-term fuel trim would drop to like -5% for a split second under extremely light loads in town or from a stop. That would cause the jerking. I have been able to smooth most of that out with this module, but in order to smooth all of it out, I would need a competent tuner to help fine tune the fuel and O2 maps to make sure they're not conflicting with each other.
One thing for everyone to keep in mind is that this isn't a magic box by any means. If a car has issues other than running too lean under closed-loop, don't expect this to solve every one of those problems. My opinion of the F/IC remains the same. It's still a half-assed solution - though unfortunately the best solution we have at the moment.
Once I'm ready for testers, I'll be looking for a vehicle with a few things...
- Forced induction
- AEM F/IC
- NO check engine lights
- People with OBD-II scanners will be given first priority. (They can tell me what their short/long-term fuel trims are)
Also, the individual should be armed with a nice multimeter and soldering iron to ensure that they have proper connections.