ECU wire for A/F
- Thread starter winreboot
- Start date
Page 11-9
Connection D14 and D16
Look for connector pinout at the bottom of this page.
Greets,
Mich
Keep in mind that the stock sensor works only over a very narrow range during idle and steady cruise, but not under hard acceleration.
winreboot,
What you are doing is TOTALLY useless... there is virtually nothing you will discern from a stock O2 sensor. You see a lot of these gauges and such for a/f and it is likely the biggest scam going. How a stock O2 sensors works is the following: when a/f is below 14.7:1 there is one voltage and when above 14.7:1 there is a higher voltage. Your stock ECU, similar to ECUs in other cars, simply uses the stock O2 to "hunt in" on the desired (ideal) a/f which is 14.7:1. In other words, there is really no way, for example, that these O2's can tell the difference between 10.0:1 and 14.0:1.
If you are trying to use the stock O2 for tuning forced induction motor, you likely want to target an ideal (under bosst) a/f of 12.5:1. If you are running under 11:1 you're too rich and if you get North of 13:1 you may be in trouble. The stock O2 or even the available aftermarket gauges CANNOT discern the difference.
The good news (sort of) is that there is a solution. In fact it is a very good one, albeit expensive. I am using it now to tune my BBSC. The kit consists of a 5-wire (expensive) O2 sensor and a black-box brain/controller. Once installed, it will let you display instantaneous a/f ratios (accurate to 1/100) and, more importantly, it will let you datalog for virtually any period of time. You can then playback the datalog or, using the supplied software, you can generate a/f graphs. There is a provision for a RPM-in (mandatory) and an auxilary in (0-5v) for a Map-in voltage, for example.
All values are datalogged.
My testing has consisted of modifying the fuel maps and then doing 4 or 5 2000-6000 full-throttle acceleration runs. (6K-8k can be tuned in after you get the hang of it.) I use 3rd gear and will use 4th gear for final tuning. It is almost essential to have a passenger with you. Have the passenger watch instantaneous a/f to make sure no values over 13:1... while datalogging the whole sequence. Next, return home and view the graphs. Make changes to the table and repeat the process.
If you are careful and methodical, I believe that this method with the right tools is the BEST way to tune a forced induction car like the BBSC. In my mind, many advantages over the Dyno.
I hope I haven't over-reacted to your O2 question, but please be careful regarding the expectations you may have on what the stock O2 can do for you.
What you are doing is TOTALLY useless... there is virtually nothing you will discern from a stock O2 sensor. You see a lot of these gauges and such for a/f and it is likely the biggest scam going. How a stock O2 sensors works is the following: when a/f is below 14.7:1 there is one voltage and when above 14.7:1 there is a higher voltage. Your stock ECU, similar to ECUs in other cars, simply uses the stock O2 to "hunt in" on the desired (ideal) a/f which is 14.7:1. In other words, there is really no way, for example, that these O2's can tell the difference between 10.0:1 and 14.0:1.
If you are trying to use the stock O2 for tuning forced induction motor, you likely want to target an ideal (under bosst) a/f of 12.5:1. If you are running under 11:1 you're too rich and if you get North of 13:1 you may be in trouble. The stock O2 or even the available aftermarket gauges CANNOT discern the difference.
The good news (sort of) is that there is a solution. In fact it is a very good one, albeit expensive. I am using it now to tune my BBSC. The kit consists of a 5-wire (expensive) O2 sensor and a black-box brain/controller. Once installed, it will let you display instantaneous a/f ratios (accurate to 1/100) and, more importantly, it will let you datalog for virtually any period of time. You can then playback the datalog or, using the supplied software, you can generate a/f graphs. There is a provision for a RPM-in (mandatory) and an auxilary in (0-5v) for a Map-in voltage, for example.
All values are datalogged.
My testing has consisted of modifying the fuel maps and then doing 4 or 5 2000-6000 full-throttle acceleration runs. (6K-8k can be tuned in after you get the hang of it.) I use 3rd gear and will use 4th gear for final tuning. It is almost essential to have a passenger with you. Have the passenger watch instantaneous a/f to make sure no values over 13:1... while datalogging the whole sequence. Next, return home and view the graphs. Make changes to the table and repeat the process.
If you are careful and methodical, I believe that this method with the right tools is the BEST way to tune a forced induction car like the BBSC. In my mind, many advantages over the Dyno.
I hope I haven't over-reacted to your O2 question, but please be careful regarding the expectations you may have on what the stock O2 can do for you.
He didn't really say what he was doing, hence my brief warning to the same effect as yours.
However, I appreciate your post because it sounds like you are already ahead of me with the portable wide band A/F logging. The process you are doing is even more important on a turbo because there is not a direct correlation between RPM and boost. But more on that one of these nights when I have time for a long write up on the subject.
Meanwhile, I have been shopping around for the "right" meter so I'm curious to know what you have and how you like it. Do you really believe it is good to .01? I don't think I've found one claiming to be that accurate. So far the one I like has both digital and analog readout on the main box as well as logging. I think this would be much simpler for the passenger to see sudden swings. Does yours have an alarm that can be set at a given level? Do you have at least one sensor in each bank and a simple way to switch between them?
Sorry for all the questions, but this is my #1 priority right now for the NSX.
BTW, someone recently found a way to get wide-band type readings from OEM sensors by using a special circuit to read their impedance (as I recall). I recently saw an article on it but would much rather stick to more proven methods even if they are costly. Just thought it was interesting though, perhaps someone out there will know more about it.
sjs,
DO you still have the url to the article you are refering to?
Thankx,
Mich
DO you still have the url to the article you are refering to?
Thankx,
Mich
I'll dig, but I doubt it. I can't even swear it was on the web, it may have been in a magazine.
sjs,
For simplicity, I have been trying to keep answers in the "a/f tuning" thread under the "Forced Induction" discussion area.
Sounds like you may have been looking at the wideband I bought (FJO), but I put more info on the other thread. I hope it's OK to continue there...
For simplicity, I have been trying to keep answers in the "a/f tuning" thread under the "Forced Induction" discussion area.
Sounds like you may have been looking at the wideband I bought (FJO), but I put more info on the other thread. I hope it's OK to continue there...
I just want to have FYI A/F readings and not to much for accurate tuning. I run 80 wet shot NOS and just went to 40 shot. And as I play with the jets I want to just have an read out on WOT only.
You guys are apsolutly right about the chip $60 meaters but for me it is untill I get Supercharger or Turbo then Fuel MAP is very important. I had custom DRAG turbo kit in 97 prelude and I went throught hell working on a 3D Fuel map.
AEM EMS replacment computer is a MUST I think with supercharged or turbo NSX. That way you can log everything on your laptop and compare DATA and tune you car the way you want it
and I think AEM has hookup to read A/F readings
Yea, I would be intrested in that article too. How they can make OE sensor to read out and wider readings ?
Thanks for you help guys.
You guys are apsolutly right about the chip $60 meaters but for me it is untill I get Supercharger or Turbo then Fuel MAP is very important. I had custom DRAG turbo kit in 97 prelude and I went throught hell working on a 3D Fuel map.
AEM EMS replacment computer is a MUST I think with supercharged or turbo NSX. That way you can log everything on your laptop and compare DATA and tune you car the way you want it
Yea, I would be intrested in that article too. How they can make OE sensor to read out and wider readings ?
Thanks for you help guys.
I don't think these gauges are totally useless. Saved my engine once. I had a supercharged Integra. The stock fuel pressure regulator was going bad. Sometimes it worked sometimes it ran the car lean. When you have your foot into it and you see the red light say lean, all I can say thank you a/f gauge.
I would not use it for tunning though.
I would not use it for tunning though.
nsxxtreme,
Cool that the meter saved you... but as I said when the meter says lean, it means REAL lean. If you're at 13.5:1 or 14.0:1, these meters will stay "rich", (south of 14.7:1) but you are really lean for boosting conditions. As you said, for gross measurement - and recognizing complete system failures, I suppose they have their purpose. Just recognize their limitations. The fewer damaged motors we have the happier we will be!
Cool that the meter saved you... but as I said when the meter says lean, it means REAL lean. If you're at 13.5:1 or 14.0:1, these meters will stay "rich", (south of 14.7:1) but you are really lean for boosting conditions. As you said, for gross measurement - and recognizing complete system failures, I suppose they have their purpose. Just recognize their limitations. The fewer damaged motors we have the happier we will be!
Hi Guys,
I have ome bad experience with running lean. It costed me 6 pistons on several occasions, before I found out, that I had a bad fuel filter. The A/F ratio was north of 13.
At this moment my A/F ratio starts below 13 from 2,3k rpm and stays between 11 and 12 from 2,5k and 7,4k and stays then between a A/F ratio of 12 and 13 untill the rev limiter.
I now feel more secured with this ratio then before. My tech says it's very important that you always stay way below 13 under boost.
I have ome bad experience with running lean. It costed me 6 pistons on several occasions, before I found out, that I had a bad fuel filter. The A/F ratio was north of 13.
At this moment my A/F ratio starts below 13 from 2,3k rpm and stays between 11 and 12 from 2,5k and 7,4k and stays then between a A/F ratio of 12 and 13 untill the rev limiter.
I now feel more secured with this ratio then before. My tech says it's very important that you always stay way below 13 under boost.
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