How the ECU works and what needs to be overcome for NA gains
05-09-2005, 12:50 PM
#1
How the ECU works and what needs to be overcome for NA gains
The following is a theory about our ECU based on everything I've read about the 350Z and G35. I haven't confirmed my findings yet, but will post this anyway since there is an interest. Maybe if everyone puts their heads together we can totally solve the issues because I only know so much about this car.
Here's a thread I'm going to refer to which I think is a big key to the ECU puzzle:
a discussion with a Nissan engineer about the ECU
https://my350z.com/forum/showthread....engineer+phone
The ECU has 3 main issues with NA mods. FI Z's don't have these issues and my theory hopefully can explain why that is.
the 3 issues are:
- MAF sensor voltage
- controlling fuel injectors
- cat O2 sensors
starting with MAF, the ECU is expecting the MAF voltage to be within the stock specifications. When you start adding NA mods, the MAF will start approaching saturation until it does get saturated and beyond the stock range that the ECU wants to see.
So the ECU will do what it can to get the MAF voltage back within stock range. The way it does that is pulling timing. When it pulls enough timing to get the voltage back where it wants to see it, then everything is fine again in the ECU's eyes. But for those of us who have spent $ on wanting that extra air flow are getting frusturated because even though our new part is giving the car more power, the ECU is pulling power to keep the MAF within range because that reduces air flow.
Even if the ECU's MAF range was much greater than it is and knew exactly how much air was going into it, the stock ECU can only do so much to add more fuel. It can't add more fuel than it was programmed to add for a given air flow level (voltage)
This is where the TS or AAM ECU flash or a piggyback that controls the injectors like the Greddy E-manage come into play. They either program the ECU to run more fuel to match the air levels or in the case of the E-manage, adds more or less fuel at a given RPM based on the ECU's fuel mapping.
The nissan engineer in my first link refered to adjusting the MAF voltage to get any real NA gains
The last checkpoint is the O2 sensors. You can adjust the fuel levels, but the more fuel you add, the worse emissions are. The ECU likes to keep the car running lean because it is extremely emissions friendly. I won't be suprised if the ECU has different emissions settings for different RPM's and how far the gas pedal is pushed down. Meaning if you do nothing but WOT on a track day - of coarse emissions would be worse than if you were just cruising on the highway, but the ECU must have different acceptable emissions ranges based on that.
The ECU likes to run on 93 octane fuel. This in part explains why people on the middle and east coast dyno higher than west coast people. The car must start knocking a little with 91 octane and thus reduces timing a little. There's also altitude, but let's stay on subject...
If you do something to add more fuel, the O2 sensors report a richer mix (which is bad for emissions) and report it to the ECU. The ECU sees this and decides it needs to start cutting fuel to lean things out until it's within stock emissions specs again. It won't stop leaning things out until it's happy. Of course we know if you lean things out too much you get detonation or ping. The knock sensor detects the pinging and the ECU decides to pull timing to reduce pinging. If the ECU still isn't happy with the emissions levels, it'll keep reducing fuel. Over and over again with reducing fuel and retarding timing, until it reaches an equilibrium.
If it can't reach an equilibrium because the ECU was only programmed to go so far, it'll go into safe mode. You'll get a Service Engine Soon light. In a case where even safe mode isn't good enough to make the ECU happy, it'll go into Limp mode. This mode won't let you rev above 2500 rpm, and all the lights on the dash will light up to let you know you have a MAJOR problem.
The nissan engineer refered to sodering some wires, I think cheating the O2 sensors is what he meant.
Here's a thread I'm going to refer to which I think is a big key to the ECU puzzle:
a discussion with a Nissan engineer about the ECU
https://my350z.com/forum/showthread....engineer+phone
The ECU has 3 main issues with NA mods. FI Z's don't have these issues and my theory hopefully can explain why that is.
the 3 issues are:
- MAF sensor voltage
- controlling fuel injectors
- cat O2 sensors
starting with MAF, the ECU is expecting the MAF voltage to be within the stock specifications. When you start adding NA mods, the MAF will start approaching saturation until it does get saturated and beyond the stock range that the ECU wants to see.
So the ECU will do what it can to get the MAF voltage back within stock range. The way it does that is pulling timing. When it pulls enough timing to get the voltage back where it wants to see it, then everything is fine again in the ECU's eyes. But for those of us who have spent $ on wanting that extra air flow are getting frusturated because even though our new part is giving the car more power, the ECU is pulling power to keep the MAF within range because that reduces air flow.
Even if the ECU's MAF range was much greater than it is and knew exactly how much air was going into it, the stock ECU can only do so much to add more fuel. It can't add more fuel than it was programmed to add for a given air flow level (voltage)
This is where the TS or AAM ECU flash or a piggyback that controls the injectors like the Greddy E-manage come into play. They either program the ECU to run more fuel to match the air levels or in the case of the E-manage, adds more or less fuel at a given RPM based on the ECU's fuel mapping.
The nissan engineer in my first link refered to adjusting the MAF voltage to get any real NA gains
He said YOU CANNOT get performance gains with out either reprograming the ecu or faking it by cutting or sodering some wires/circuts and making it think it is running in normal specs. He said thats what aftermarket companies do when they "so called reprogram" the ecu and then charge $1300 bucks for it...(he laughed at that).... He said without faking it would do something about running in fail safe mode which makes it even crapper than stock specs....his example to my dumb *** was like windows 98 running in safe mode when there is a error.
He told me to save my money on the aftermarket mods until the air/fuel mapping info is released.
He said that a K&N won't make that much differences because of the way the 02 computers are run...It would just last longer than a normal airfilter.
He kept on saying the ECM needs to be reprogramed and released...OR cheaply faking out the computer by messing with the o2 sensors.
He told me that a easy way to prove that your aftermarket bolt ons aren't working would be to to run emmission tests before and after...if they are the same then your ECU compensated for the bolt on and just changed the mapping back to normal specs aka no gain OR defaulted to fail safe mode aka loss HP
He said that any mod would have to have the program retuned on the ECM to keep the computer from thinking its running too lean or rich. He said emissions are a big source for finding HP and mentions something about 320 hp total for a correctly tuned ecu.
Thats what he heard was capable of...
He said that he knows the specs/diagram of the ecu very well and what wire would need to be cut and resistors that need to be placed.
He told me to save my money on the aftermarket mods until the air/fuel mapping info is released.
He said that a K&N won't make that much differences because of the way the 02 computers are run...It would just last longer than a normal airfilter.
He kept on saying the ECM needs to be reprogramed and released...OR cheaply faking out the computer by messing with the o2 sensors.
He told me that a easy way to prove that your aftermarket bolt ons aren't working would be to to run emmission tests before and after...if they are the same then your ECU compensated for the bolt on and just changed the mapping back to normal specs aka no gain OR defaulted to fail safe mode aka loss HP
He said that any mod would have to have the program retuned on the ECM to keep the computer from thinking its running too lean or rich. He said emissions are a big source for finding HP and mentions something about 320 hp total for a correctly tuned ecu.
Thats what he heard was capable of...
He said that he knows the specs/diagram of the ecu very well and what wire would need to be cut and resistors that need to be placed.
He talked about that alot....something to do with the volts on each sensor...if they are changed the ECU realizes the volt change....lets say increased intake flow. The volts would increase...well if that increases it may make the car, he said " vibrate or idle weird" then the ecu will constantly correct itself to reduce the volts back to normal on that sensor. IF it cant it will go to fail safe mode...I still dont totally understand that. He said to properly make any mod work for a gain...Which most mods normally increase oxygen (more airflow). You need to know which sensors get effected by that mod directly and trick them to report to the ecu that they are maintaing the proper volt. He told me a cheap way was using a resistor and a screw...and screw it in till it reads the right volt.....does that make sense???????
The last checkpoint is the O2 sensors. You can adjust the fuel levels, but the more fuel you add, the worse emissions are. The ECU likes to keep the car running lean because it is extremely emissions friendly. I won't be suprised if the ECU has different emissions settings for different RPM's and how far the gas pedal is pushed down. Meaning if you do nothing but WOT on a track day - of coarse emissions would be worse than if you were just cruising on the highway, but the ECU must have different acceptable emissions ranges based on that.
The ECU likes to run on 93 octane fuel. This in part explains why people on the middle and east coast dyno higher than west coast people. The car must start knocking a little with 91 octane and thus reduces timing a little. There's also altitude, but let's stay on subject...
If you do something to add more fuel, the O2 sensors report a richer mix (which is bad for emissions) and report it to the ECU. The ECU sees this and decides it needs to start cutting fuel to lean things out until it's within stock emissions specs again. It won't stop leaning things out until it's happy. Of course we know if you lean things out too much you get detonation or ping. The knock sensor detects the pinging and the ECU decides to pull timing to reduce pinging. If the ECU still isn't happy with the emissions levels, it'll keep reducing fuel. Over and over again with reducing fuel and retarding timing, until it reaches an equilibrium.
If it can't reach an equilibrium because the ECU was only programmed to go so far, it'll go into safe mode. You'll get a Service Engine Soon light. In a case where even safe mode isn't good enough to make the ECU happy, it'll go into Limp mode. This mode won't let you rev above 2500 rpm, and all the lights on the dash will light up to let you know you have a MAJOR problem.
The nissan engineer refered to sodering some wires, I think cheating the O2 sensors is what he meant.
05-09-2005, 12:51 PM
#2
continued...
Ok, so let's go over some scenerios.
you do a ton of NA mods and add the Emanage piggyback or TS or AAM ECU flash which basically adjusts the injectors (not going to touch on the other stuff since it's a little off subject). Car runs great for awhile, then later stops running great and doesn't seem as fast anymore, but you're maybe not totally sure because it's been a kinda gradual transition. Chances are the MAF is oversaturated and the ECU is pulling timing. The more timing that's pulled, the richer the mix gets. The O2 sensor's pick that up and tell the ECU and the ECU decides that it's bad for emissions. So it starts cutting fuel. As it cuts more and more fuel, you eventually will ping. It pulls more timing to compensate for the pinging, etc until you reach equilibrum or the ECU gives up and puts you in save mode. It's a cycle that can take awhile to reach because for each adjustment, the ECU has to gather data about how well that change is working. So step by step it gradually makes you lose power to the point where you start wondering why the car feels slower.
Another example:
You do your ton of NA mods and add the Apexi AFCII which adjusts MAF voltage. You get it tuned, it runs great - nice flat A/F curve. Might note that you can't do MAJOR adjustments with the Apexi unit, because you're relying on the ECU to deliver maximum "stock" fuel levels. The ECU can't deliver more fuel on it's own that it was designed to give you. So if you have TONS of major NA mods, you might not do so well with JUST the apexi by itself because you need MORE than stock fuel levels. For minor mods, it'll probably be fine. What you're doing is preventing the MAF from oversaturating and thus eliminating the ECU from wanting to reduce timing (and fuel as that cycle would start).
So your car is running great and things are good for a bit....But assuming you have MAJOR NA mods and gotta make the Apexi work really hard to keep the MAF voltage within range you'll run into problems. All you're doing is fooling the ECU with the air level going in the engine. It thinks stock levels of air are going in the engine but there's really LOTS more air going thru the engine. Of course since the ECU thinks there's stock air levels in the engine, it adds stock fuel levels to the A/F mix. Actually it adds probably the most amount of fuel it can because it thinks things are great...
But since there's really more air than stock, you are running LEAN. Sooner or later, you'll probably hit that knock sensor and the ECU will start pulling timing because knocking is bad. It'll pull timing until it stops knocking - or actually I think it might pull lots of timing, then gradually work it's way back up until it detects knock again, then goes back down a level until you get maximum power without knocking. That's one good feature about the ECU - maximum power without knocking. The thing is, the other sensors are working against you making the ECU thinking things are bad when the reality is they aren't. So to reduce knocking, you need more fuel. With the Apexi unit, you're not adding more fuel. You're just fooling the ECU's MAF readings to give you the most fuel the stock fuel mappings can give you.
Another example:
you have tons of NA mods - especially in the case of test pipes will this example ring true. You throw a Service Engine Soon (SES) light because you removed your cats and replaced them with test pipes. By itself, no biggie, it just raises your A/F 1 bar or so. But combined with other NA breathing mods, you can throw a light because the polutants are just too great for the ECU to be comfortable. This seems to be true with many modern cars using test pipes. It's especially true with test pipes, because there's no cat to reduce emissions levels and the O2 sensors pick up on it. The ECU determines something is wrong with emissions and pops up that SES code. It might actually try reducing fuel and timing, but I'm not sure in this case - it might be so far off it just imediately throws the SES light and goes pretty much into safe mode.
So you read up on how you can solder a resister into the O2 sensor wiring or get the non fouler extender fix. You install it, it eliminates the SES light and keeps you from going into safe mode. Good deal. It works. Nothing else changes about the engine. Except the test pipes (or extreme NA mods ) are still running the engine lean. If you have major NA mods you're going to have multiple problems with the ECU, not just 1 or 2. Doing the O2 sensor mod isn't going to solve the other 2 issues with fuel and MAF voltage.
So what needs to be done?
get a standalone EMS. Only one currently on the market is the HKS Fcon V-pro. The unit, harness, and all sensors, install, and tuning will run you in the $3000-3500 range. Can also only be installed at an HKS dealer who has completed the Fcon training. It overides the ECU's settings and does exactly what you say. If you say I want 12.5 or 13 A/F ratio across the board, it'll make the adjustments to do so without pulling timing - unless your injectors are not strong enough.
AEM might come out with their for the Z, but who knows when. Their's might be superior to the HKS, more people are familiar with tuning the AEM units, and will probably be more widely available for tuning in different shops unlike HKS.
or
- the MAF voltage needs to report stock range voltages to the ECU - the APEXI AFCII does this
- the fuel injectors need to inject more fuel. Technosquare (TS) or Altered Atmosphere (AAM) ECU flashes do this as well as add more timing. Or a piggyback like the Greddy E-manage that controls the injectors based on the ECU mappings.
- do the O2 sensor non fouler mod for the sake of ensuring the ECU won't try to compensate for worse than stock emissions.
In theory, if you have a proper A/F ratio, the ECU should be fine with what the O2 sensors report. The problem with NA depends on a person's setup. Most people who have tried to tune their NA setup have done so with 1 tuning method. Either TS or AAM flash, E-manage, or the Apexi unit and get mixed or changing results probably depending on what octane fuel they use and just how many NA they really have. Some people with test pipes use the O2 sensor non-fouler mod, but that's more of a prevention thing.
Running the O2 sensor non-fouler mod is probably fine - so long as YOU know what your A/F is. It doesn't matter so much if the computer doesn't actually know what the real A/F or emissions are. It needs to believe it's running within stock specs. But YOU need to know what the A/F is if you're going to be doing major mods. If you just have bolt on mods and know the A/F is good, chances are the emissions will be fine - unless you're running test pipes in which case of coarse they won't be good - you have no cat!
I believe on FI kits, the two major things that are taken into consideration with the engine managment that comes with FI kits is the MAF voltage and fuel injection. I believe I read somewhere that when companies were designing FI kits, the MAF voltage was one of the things they had to find a way to overcome with their tuning software. This would explain why FI kits seem to gain horsepower and keep it and make it very tunable - because they keep a leash on the MAF voltage and you have control over fuel injection.
I might note that NA people approaching 300whp, you might need to consider upgrading the fuel system and injectors with a way to tune them. Even the stillen Stage 1 supercharger with 300-310 whp adds a 7th injector for more fuel. Or at least run really high octane fuel if you're going to be pushing the car to redline a lot to prevent detonation.
resetting the ECU helps people with a lot of NA mods to keep their power and fuel (and no it won't erase the TS or AAM ECU reflash programing) because it resets it back to the "normal" timing/fuel maps. It won't last though and will gradually degrade as the ECU tries to "fix" the situation that the mods are causing until it's back to stock specs.
I should also state, that as long as you have a working engine, and working cats on your Z, you'll probably pass emissions, though kinda depends on how strict your state is. Technically, doing the O2 cat sensor is illegal from emissions point of view because you're interfering with the gov't approved emissions control of your engine - but in reality they're not actually BAD emissions, just the ECU doesn't know what's raelly going on because it wasn't programmed to understand the much higher air flow levels that big NA mods can give you.
...again this is all theoretical based on my readings. Please add any info you have or explain the situation of your car and how it's reacting...
you do a ton of NA mods and add the Emanage piggyback or TS or AAM ECU flash which basically adjusts the injectors (not going to touch on the other stuff since it's a little off subject). Car runs great for awhile, then later stops running great and doesn't seem as fast anymore, but you're maybe not totally sure because it's been a kinda gradual transition. Chances are the MAF is oversaturated and the ECU is pulling timing. The more timing that's pulled, the richer the mix gets. The O2 sensor's pick that up and tell the ECU and the ECU decides that it's bad for emissions. So it starts cutting fuel. As it cuts more and more fuel, you eventually will ping. It pulls more timing to compensate for the pinging, etc until you reach equilibrum or the ECU gives up and puts you in save mode. It's a cycle that can take awhile to reach because for each adjustment, the ECU has to gather data about how well that change is working. So step by step it gradually makes you lose power to the point where you start wondering why the car feels slower.
Another example:
You do your ton of NA mods and add the Apexi AFCII which adjusts MAF voltage. You get it tuned, it runs great - nice flat A/F curve. Might note that you can't do MAJOR adjustments with the Apexi unit, because you're relying on the ECU to deliver maximum "stock" fuel levels. The ECU can't deliver more fuel on it's own that it was designed to give you. So if you have TONS of major NA mods, you might not do so well with JUST the apexi by itself because you need MORE than stock fuel levels. For minor mods, it'll probably be fine. What you're doing is preventing the MAF from oversaturating and thus eliminating the ECU from wanting to reduce timing (and fuel as that cycle would start).
So your car is running great and things are good for a bit....But assuming you have MAJOR NA mods and gotta make the Apexi work really hard to keep the MAF voltage within range you'll run into problems. All you're doing is fooling the ECU with the air level going in the engine. It thinks stock levels of air are going in the engine but there's really LOTS more air going thru the engine. Of course since the ECU thinks there's stock air levels in the engine, it adds stock fuel levels to the A/F mix. Actually it adds probably the most amount of fuel it can because it thinks things are great...
But since there's really more air than stock, you are running LEAN. Sooner or later, you'll probably hit that knock sensor and the ECU will start pulling timing because knocking is bad. It'll pull timing until it stops knocking - or actually I think it might pull lots of timing, then gradually work it's way back up until it detects knock again, then goes back down a level until you get maximum power without knocking. That's one good feature about the ECU - maximum power without knocking. The thing is, the other sensors are working against you making the ECU thinking things are bad when the reality is they aren't. So to reduce knocking, you need more fuel. With the Apexi unit, you're not adding more fuel. You're just fooling the ECU's MAF readings to give you the most fuel the stock fuel mappings can give you.
Another example:
you have tons of NA mods - especially in the case of test pipes will this example ring true. You throw a Service Engine Soon (SES) light because you removed your cats and replaced them with test pipes. By itself, no biggie, it just raises your A/F 1 bar or so. But combined with other NA breathing mods, you can throw a light because the polutants are just too great for the ECU to be comfortable. This seems to be true with many modern cars using test pipes. It's especially true with test pipes, because there's no cat to reduce emissions levels and the O2 sensors pick up on it. The ECU determines something is wrong with emissions and pops up that SES code. It might actually try reducing fuel and timing, but I'm not sure in this case - it might be so far off it just imediately throws the SES light and goes pretty much into safe mode.
So you read up on how you can solder a resister into the O2 sensor wiring or get the non fouler extender fix. You install it, it eliminates the SES light and keeps you from going into safe mode. Good deal. It works. Nothing else changes about the engine. Except the test pipes (or extreme NA mods ) are still running the engine lean. If you have major NA mods you're going to have multiple problems with the ECU, not just 1 or 2. Doing the O2 sensor mod isn't going to solve the other 2 issues with fuel and MAF voltage.
YOU CANNOT get performance gains with out either reprograming the ecu or faking it by cutting or sodering some wires/circuts and making it think it is running in normal specs.
get a standalone EMS. Only one currently on the market is the HKS Fcon V-pro. The unit, harness, and all sensors, install, and tuning will run you in the $3000-3500 range. Can also only be installed at an HKS dealer who has completed the Fcon training. It overides the ECU's settings and does exactly what you say. If you say I want 12.5 or 13 A/F ratio across the board, it'll make the adjustments to do so without pulling timing - unless your injectors are not strong enough.
AEM might come out with their for the Z, but who knows when. Their's might be superior to the HKS, more people are familiar with tuning the AEM units, and will probably be more widely available for tuning in different shops unlike HKS.
or
- the MAF voltage needs to report stock range voltages to the ECU - the APEXI AFCII does this
- the fuel injectors need to inject more fuel. Technosquare (TS) or Altered Atmosphere (AAM) ECU flashes do this as well as add more timing. Or a piggyback like the Greddy E-manage that controls the injectors based on the ECU mappings.
- do the O2 sensor non fouler mod for the sake of ensuring the ECU won't try to compensate for worse than stock emissions.
In theory, if you have a proper A/F ratio, the ECU should be fine with what the O2 sensors report. The problem with NA depends on a person's setup. Most people who have tried to tune their NA setup have done so with 1 tuning method. Either TS or AAM flash, E-manage, or the Apexi unit and get mixed or changing results probably depending on what octane fuel they use and just how many NA they really have. Some people with test pipes use the O2 sensor non-fouler mod, but that's more of a prevention thing.
Running the O2 sensor non-fouler mod is probably fine - so long as YOU know what your A/F is. It doesn't matter so much if the computer doesn't actually know what the real A/F or emissions are. It needs to believe it's running within stock specs. But YOU need to know what the A/F is if you're going to be doing major mods. If you just have bolt on mods and know the A/F is good, chances are the emissions will be fine - unless you're running test pipes in which case of coarse they won't be good - you have no cat!
I believe on FI kits, the two major things that are taken into consideration with the engine managment that comes with FI kits is the MAF voltage and fuel injection. I believe I read somewhere that when companies were designing FI kits, the MAF voltage was one of the things they had to find a way to overcome with their tuning software. This would explain why FI kits seem to gain horsepower and keep it and make it very tunable - because they keep a leash on the MAF voltage and you have control over fuel injection.
I might note that NA people approaching 300whp, you might need to consider upgrading the fuel system and injectors with a way to tune them. Even the stillen Stage 1 supercharger with 300-310 whp adds a 7th injector for more fuel. Or at least run really high octane fuel if you're going to be pushing the car to redline a lot to prevent detonation.
resetting the ECU helps people with a lot of NA mods to keep their power and fuel (and no it won't erase the TS or AAM ECU reflash programing) because it resets it back to the "normal" timing/fuel maps. It won't last though and will gradually degrade as the ECU tries to "fix" the situation that the mods are causing until it's back to stock specs.
I should also state, that as long as you have a working engine, and working cats on your Z, you'll probably pass emissions, though kinda depends on how strict your state is. Technically, doing the O2 cat sensor is illegal from emissions point of view because you're interfering with the gov't approved emissions control of your engine - but in reality they're not actually BAD emissions, just the ECU doesn't know what's raelly going on because it wasn't programmed to understand the much higher air flow levels that big NA mods can give you.
...again this is all theoretical based on my readings. Please add any info you have or explain the situation of your car and how it's reacting...
05-09-2005, 01:08 PM
#3
Sponsor
Forged Internals.com
Forged Internals.com
I'll just keep editing this post as I read. The ECU pulling timing from readings from the MAF sensor is kind of wrong, if it pulls timing, it's going to notice a difference in emissions at the narrowband (pre '05) (or wideband for '05's) O2 sensor. So IMO, it would retard the timing back because, to me, it would seem like emissions are more important to the ECU operating efficiently than increased air flow.
Good summary overall. Glad to see someone finally put everything together.
Also, there are two other standalone options, the MoTeC M600 or M800 and Autronic SM2.
Good summary overall. Glad to see someone finally put everything together.
Also, there are two other standalone options, the MoTeC M600 or M800 and Autronic SM2.
Last edited by nis350ztt; 05-09-2005 at 01:16 PM.
05-09-2005, 01:21 PM
#4
yeah forgot about the motec standalones, but never have heard of the autronic unit
Does anyone know if it would be beneficial at all to put wideband O2 sensors in place of the narrowband O2 sensors?
A standalone would need widebands right?
I thought I read that early 03's had narrowband, and later 03's and higher all had wideband?
you might be right about the MAF and pulling timing, but if you're running lean from mods and saturating the MAF, wouldn't emissions check out ok? lean is good for emissions, rich isn't right?
Does anyone know if it would be beneficial at all to put wideband O2 sensors in place of the narrowband O2 sensors?
A standalone would need widebands right?
I thought I read that early 03's had narrowband, and later 03's and higher all had wideband?
you might be right about the MAF and pulling timing, but if you're running lean from mods and saturating the MAF, wouldn't emissions check out ok? lean is good for emissions, rich isn't right?
Last edited by sentry65; 05-09-2005 at 01:37 PM.
05-09-2005, 01:41 PM
#5
Originally Posted by sentry65
yeah forgot about the motec standalones, but never have heard of the autronic unit
Does anyone know if it would be beneficial at all to put wideband O2 sensors in place of the narrowband O2 sensors?
A standalone would need widebands right?
I thought I read that early 03's had narrowband, and later 03's and higher all had wideband?
you might be right about the MAF and pulling timing, but if you're running lean from mods and saturating the MAF, wouldn't emissions check out ok? lean is good for emissions, rich isn't right?
Does anyone know if it would be beneficial at all to put wideband O2 sensors in place of the narrowband O2 sensors?
A standalone would need widebands right?
I thought I read that early 03's had narrowband, and later 03's and higher all had wideband?
you might be right about the MAF and pulling timing, but if you're running lean from mods and saturating the MAF, wouldn't emissions check out ok? lean is good for emissions, rich isn't right?
05-09-2005, 01:43 PM
#6
for those who have no idea what modding the O2 sensors is
you don't actually use the parts as they were originally intended with spark plugs
the alternative involves soldering some wires - note the nissan engineer said the same thing. This method can be undone easily and doesn't require soldering.
ONLY DO THIS IF YOU EITHER HAVE TEST PIPES OR TONS MORE AIR FLOW THAN STOCK - TO THE POINT WHERE YOUR CAR TRIPS SES OR CEL LIGHTS
otherwise who knows how the car will react. It might start running really rich - which could be good or bad depending on where you live and what gas you run. It's up to you at your own risk to try it
here's a compilation of all sorts of quotes I've saved about them from users from all sorts of websites.
they are called spark plug anti-foulers. i have them on my msp w/ corksport exhaust. use the 18mm ones and just drill out the bottom of one of them with a 1/2" drill bit (do not cut it off) and screw them into each other. it creates a chamber outside the main exhaust fow for the o2 to get a proper reading. suby guys have been doing this for a while with no cel/mil.
The heat will make the O2 active, but since it's out of the more laminar flow, that means less poloutants get to the O2 sensor, and thusly, it thinks the air is catalyzed.
i just went and got the HELP! Spark plug non fouler. Part 42002 for 3.99 from autozone.
Its a 2 pack, that you screw together, and then screw the open end into the o2, and the other into the bung.
This does require that you drill out the hole to allow for more flow to the o2, but thats pretty easy.
We datalogged the effects and it keeps it at the voltage where it thinks theres a cat there.
Never thrown a cel with this fix, proving once again it works
you don't actually use the parts as they were originally intended with spark plugs
the alternative involves soldering some wires - note the nissan engineer said the same thing. This method can be undone easily and doesn't require soldering.
ONLY DO THIS IF YOU EITHER HAVE TEST PIPES OR TONS MORE AIR FLOW THAN STOCK - TO THE POINT WHERE YOUR CAR TRIPS SES OR CEL LIGHTS
otherwise who knows how the car will react. It might start running really rich - which could be good or bad depending on where you live and what gas you run. It's up to you at your own risk to try it
here's a compilation of all sorts of quotes I've saved about them from users from all sorts of websites.
they are called spark plug anti-foulers. i have them on my msp w/ corksport exhaust. use the 18mm ones and just drill out the bottom of one of them with a 1/2" drill bit (do not cut it off) and screw them into each other. it creates a chamber outside the main exhaust fow for the o2 to get a proper reading. suby guys have been doing this for a while with no cel/mil.
The heat will make the O2 active, but since it's out of the more laminar flow, that means less poloutants get to the O2 sensor, and thusly, it thinks the air is catalyzed.
i just went and got the HELP! Spark plug non fouler. Part 42002 for 3.99 from autozone.
Its a 2 pack, that you screw together, and then screw the open end into the o2, and the other into the bung.
This does require that you drill out the hole to allow for more flow to the o2, but thats pretty easy.
We datalogged the effects and it keeps it at the voltage where it thinks theres a cat there.
Never thrown a cel with this fix, proving once again it works
Last edited by sentry65; 05-09-2005 at 01:49 PM.
05-09-2005, 02:00 PM
#7
Sponsor
Forged Internals.com
Forged Internals.com
Originally Posted by sentry65
yeah forgot about the motec standalones, but never have heard of the autronic unit
Does anyone know if it would be beneficial at all to put wideband O2 sensors in place of the narrowband O2 sensors?
A standalone would need widebands right?
I thought I read that early 03's had narrowband, and later 03's and higher all had wideband?
you might be right about the MAF and pulling timing, but if you're running lean from mods and saturating the MAF, wouldn't emissions check out ok? lean is good for emissions, rich isn't right?
Does anyone know if it would be beneficial at all to put wideband O2 sensors in place of the narrowband O2 sensors?
A standalone would need widebands right?
I thought I read that early 03's had narrowband, and later 03's and higher all had wideband?
you might be right about the MAF and pulling timing, but if you're running lean from mods and saturating the MAF, wouldn't emissions check out ok? lean is good for emissions, rich isn't right?
Putting wideband O2 sensors for the ECU to monitor would be a negative, it's going to be tougher to see gains because the ECU will have a more advanced method of detecting changes. (afterall, the only reason the ECU is doing all of this is because it thinks the atmosphere is changing)
No, but it makes tuning tons easier to tune.
Me and Peter discussed this, August of '04 was when 350Z's started getting wideband O2 sensors instead of narrowband that had been used before that. So you can determine the model year from that.
Lean is good for emissions, correct. However, if it leans too much it might go into limp mode, i'm not sure exactly what would happen. I'm not sure if the engine will start knocking/pinging and the ECU will use the knock sensor and adjust timing or what.
You should check out the Autronic SM2...it is simply awesome, and the automatic tuning feature is very cool.
Trending Topics
05-09-2005, 02:03 PM
#8
Sponsor
Forged Internals.com
Forged Internals.com
BTW, how can we be sure that this guy is really a Nissan engineer? Has he ever proved it? Even if he is legit, how do we know the information is true? (especially when results are showing different results)
05-09-2005, 02:12 PM
#9
yeah I know, we have no way to know for sure that guy really was a nissan engineer, but the interviewer used to own part of my350z.com so unless he was lying to us, or yeah if the engineer wasn't who he said he was.
I thought the info seemed pretty genuine though from how it was written. I'm not sure WHY a nissan engineer would discuss the ECU etc - maybe he's allowed to with no repurcussions? It's not like they're really trade secrets so much since the car is out on the market and people will eventually figure it all out anyway. Most modern cars work that way these days anyway
I'll look into the autronic SM2, don't know much about it. There's an authorized HKS dealer near my house though that says they can install and tune an Fcon V-pro though and lots of people, especially in europe say it's a really great EMS too. I want to explore all the options.
Motec I gathered was just too expensive and involved for a normal tuning shop to use. I want to use something people have experience with and know how to use, not guessing at.
I think that was one of the things that made the HKS EMS cost as much as it does was that you had to buy all new sensors for it.
I started another thread asking if you could use the apexi and Emanage at the same time, but I doubt anyone has tried it. It'd all be guesswork at best. And there's still that possiblility of it not working right. So to me, an EMS seems the best route
I'll keep tabs on Mazzoo's posts, but he is running FI and just has a monster car in general so he's going to have a drastically different car than an NA one with bolt on's
I thought the info seemed pretty genuine though from how it was written. I'm not sure WHY a nissan engineer would discuss the ECU etc - maybe he's allowed to with no repurcussions? It's not like they're really trade secrets so much since the car is out on the market and people will eventually figure it all out anyway. Most modern cars work that way these days anyway
I'll look into the autronic SM2, don't know much about it. There's an authorized HKS dealer near my house though that says they can install and tune an Fcon V-pro though and lots of people, especially in europe say it's a really great EMS too. I want to explore all the options.
Motec I gathered was just too expensive and involved for a normal tuning shop to use. I want to use something people have experience with and know how to use, not guessing at.
I think that was one of the things that made the HKS EMS cost as much as it does was that you had to buy all new sensors for it.
I started another thread asking if you could use the apexi and Emanage at the same time, but I doubt anyone has tried it. It'd all be guesswork at best. And there's still that possiblility of it not working right. So to me, an EMS seems the best route
I'll keep tabs on Mazzoo's posts, but he is running FI and just has a monster car in general so he's going to have a drastically different car than an NA one with bolt on's
Last edited by sentry65; 05-09-2005 at 02:20 PM.
05-09-2005, 02:31 PM
#10
So the ECU will do what it can to get the MAF voltage back within stock range. The way it does that is pulling timing. When it pulls enough timing to get the voltage back where it wants to see it, then everything is fine again in the ECU's eyes.
Initially, my concern with this was, at what voltage (i.e. signal level) does this system top out at? Because the flow rates of F/I systems are much higher than N/A, if you exceed the signal capability of the MAF system, you effectively exceed the ECU's ability to add fuel based on MAF voltage. I've been assured, however, that at the boost pressures achievable with stock internals, the MAF is a very accurate system, and by some judgements, the best way to manage the engine. When you max it out however, the ECU can only add fuel based on a single variable; RPM. At that point, it becomes impossible to further "tune" the engine.
As for the O2 sensors, you wouldn't add more fuel without adding more air (the reason for adding more fuel in the first place). The O2 sensors should see the same data whether you are pumping fuel into the car at 2 LPH or 200 LPH (not real numbers) because you're adding air accordingly such that the emissions, though greater in quantity are of the same ratio as a stock car.
Even if the ECU's MAF range was much greater than it is and knew exactly how much air was going into it, the stock ECU can only do so much to add more fuel. It can't add more fuel than it was programmed to add for a given air flow level (voltage)
You make some valid observations and points though, and the end result is that if you want total engine control, it's going to cost you.
Last edited by kcobean; 05-09-2005 at 02:33 PM.
05-09-2005, 02:45 PM
#11
I was assuming, if by pulling timing, the engine will draw less air into it since it won't be as powerful.
If it doesn't suck as much air in because it now has less suction power, it'll get the MAF to reduce it's voltage
I could be wrong though since I was making an assumption
your statement about the O2 sensors is confusing me a little. I was thinking like what you are saying in that as long as the A/F and MAF voltage is within stock specs, that the O2 sensors would be happy reguardless if you're making 287 crank hp or 2000 hp passing by the sensor.
and yeah, I don't know if the ECU actually has a limitation in itself, but I do think I read that the stock 290cc injectors are barely adequate for over 300 (or was it 320) crank hp for any use of time at WOT. Also the stock fuel pump is close to maxed out too.
thanks for your post, I don't know so much about FI tuning on the Z and all the details, I've kinda been making some assumptions and hoping others would correct me. Hopefully if we pool enough info together, we'll solve the puzzle.
Ultimatly, I think the only way to fix the ECU is to basically bypass it with an EMS. And the only way to get past the fuel system is to upgrade to a return system and upgrade the fuel pump and injectors, then tune...
If it doesn't suck as much air in because it now has less suction power, it'll get the MAF to reduce it's voltage
I could be wrong though since I was making an assumption
your statement about the O2 sensors is confusing me a little. I was thinking like what you are saying in that as long as the A/F and MAF voltage is within stock specs, that the O2 sensors would be happy reguardless if you're making 287 crank hp or 2000 hp passing by the sensor.
and yeah, I don't know if the ECU actually has a limitation in itself, but I do think I read that the stock 290cc injectors are barely adequate for over 300 (or was it 320) crank hp for any use of time at WOT. Also the stock fuel pump is close to maxed out too.
thanks for your post, I don't know so much about FI tuning on the Z and all the details, I've kinda been making some assumptions and hoping others would correct me. Hopefully if we pool enough info together, we'll solve the puzzle.
Ultimatly, I think the only way to fix the ECU is to basically bypass it with an EMS. And the only way to get past the fuel system is to upgrade to a return system and upgrade the fuel pump and injectors, then tune...
05-09-2005, 03:03 PM
#12
Registered User
iTrader: (13)
Join Date: Apr 2005
Location: B'ham Al
Posts: 1,949
Likes: 0
Received 0 Likes
on
0 Posts
I say we just drop a V10 Viper engine in all our cars and be done with it!
Or a good ole 327 from the 70's that had none of this weeny-whiny electronics, a set of burnt out glass packs, a stolen stereo from radio shack and a 8 track tape of Hank Williams Jr.
All this electronic emmissions stuff makes my lumpy head hurt.
Or a good ole 327 from the 70's that had none of this weeny-whiny electronics, a set of burnt out glass packs, a stolen stereo from radio shack and a 8 track tape of Hank Williams Jr.
All this electronic emmissions stuff makes my lumpy head hurt.
05-09-2005, 05:14 PM
#13
Registered User
Join Date: Feb 2005
Location: PLANET Z
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
what ever happend to the resistor mod,,,you know those small diodes from radio shack @ 25cent a pack of 5
the sensors in the Z reports back to the computer in electrical signals lets say after a cold air install the MAF reading is like 2 OHMs to the negative side cant we then just add a 2 OMS diode to the positive wire on the MAF side to trick the computer
the sensors in the Z reports back to the computer in electrical signals lets say after a cold air install the MAF reading is like 2 OHMs to the negative side cant we then just add a 2 OMS diode to the positive wire on the MAF side to trick the computer
05-09-2005, 05:33 PM
#14
Thank you Sentry65 for taking the time to put this thread together.
You have summarized and explained why modding the Z can be so difficult.
It is SAD that we must either figure out a hack to our ECU or bypass it if we are ever to reap the potential of this engine.
Since you have posted this, I have noticed (the usual) many newbies posting questions about how best to mod this car. I am so tempted to point them to your thread.....but I know they would never understand it. Not because you have not done a spectacular job, but because the problems and answers are so complex.
You have confirmed in my mind, that achieving that ellusive 50 to 75 in extra horsepower, is more expensive than anyone (especially newbies) would imagine.
Thanks again. Good write-up.
You have summarized and explained why modding the Z can be so difficult.
It is SAD that we must either figure out a hack to our ECU or bypass it if we are ever to reap the potential of this engine.
Since you have posted this, I have noticed (the usual) many newbies posting questions about how best to mod this car. I am so tempted to point them to your thread.....but I know they would never understand it. Not because you have not done a spectacular job, but because the problems and answers are so complex.
You have confirmed in my mind, that achieving that ellusive 50 to 75 in extra horsepower, is more expensive than anyone (especially newbies) would imagine.
Thanks again. Good write-up.
05-09-2005, 05:50 PM
#15
Registered User
Join Date: Feb 2003
Location: central ny
Posts: 1,703
Likes: 0
Received 0 Likes
on
0 Posts
Why would TS and other companies release products that only half work? They must realize that their programs are being negated...
I wonder how the stock ECU would react to bigger injectors and a new fuel pump, without any tuning at all?
Allow me to make an observation for the sake of understanding how this ECU works a little better. Please feel free to correct me, or add to what I say. I apologize if this strays OT slightly (it's still related though).
Alot of people claim that it is a learning ECU, that adapts to your driving habits. I think the problem with that is, regardless of how well it can adapt to your driving habits (like if you drove WOT all of the time), it has to fight the altitude, temperature, humidity, and airflow, which affects timing and fuel levels in order to provide clean emissions and engine safety. This is probably the reason why so many people find the 350Z inconsistent even in stock form. My car (which remains stock)can feel fast and slow within the same day. Where you live can be significant with regard to this.
There is a difference between weather and climate. I live by a lake where the temperature and humidity drastically change. We have "weather" here in general, whereas people in certain parts of Cali have "climate". Maybe it's possible that a vast majority of the people complaining about the Z feeling inconsistent, live in an area like myself.
I wonder how the stock ECU would react to bigger injectors and a new fuel pump, without any tuning at all?
Allow me to make an observation for the sake of understanding how this ECU works a little better. Please feel free to correct me, or add to what I say. I apologize if this strays OT slightly (it's still related though).
Alot of people claim that it is a learning ECU, that adapts to your driving habits. I think the problem with that is, regardless of how well it can adapt to your driving habits (like if you drove WOT all of the time), it has to fight the altitude, temperature, humidity, and airflow, which affects timing and fuel levels in order to provide clean emissions and engine safety. This is probably the reason why so many people find the 350Z inconsistent even in stock form. My car (which remains stock)can feel fast and slow within the same day. Where you live can be significant with regard to this.
There is a difference between weather and climate. I live by a lake where the temperature and humidity drastically change. We have "weather" here in general, whereas people in certain parts of Cali have "climate". Maybe it's possible that a vast majority of the people complaining about the Z feeling inconsistent, live in an area like myself.
Last edited by phile; 05-09-2005 at 05:52 PM.
05-09-2005, 05:53 PM
#16
thanks jcn30127,
i'm planning on getting an EMS and new fuel system for my Z in a couple months. For NA, we'll see how much power I do or don't make. I hope to gain some power, but if I can just tame the car from trying to constantly adjust everything and flatten out my A/F curve I'll be happy.
An EMS isn't money wasted. Even someday when I decide to dump tons of cash to go FI, I can still make use of it and probably have more control than the standard piggybacks/engine managment systems the FI kits come with.
For some reason I seem to recall that the nissan NA team's Z's have around 380 crank hp. They're limited in the things they can change for the class they race in, but they do have a Motec ECU - which is probalby the best, most expensive, and most involved EMS out there.
I have no idea how well it'll work out, but if the "nissan engineer" is right, maybe an EMS is not a bad 1st mod if you can gain 33 crank hp with it on a stock Z.
it's all speculation. This car is not user friendly in even the slightest for power mods - not even FI. The engine isn't made for FI. Problem is we all like the car and nissan isn't going to help us out on our quest to modding it.
I think TS and AAM flashes do exactly what they say they'll do. They add more power, and balance the A/F better. But we're misled by our own assumptions into thinking it'll solve all the issues. They're adjusting the ignition/fuel mappings, not all the sensor parameters - that I know of. Maybe one of them can jump in and say exactly what they modify when they do flashes.
i'm planning on getting an EMS and new fuel system for my Z in a couple months. For NA, we'll see how much power I do or don't make. I hope to gain some power, but if I can just tame the car from trying to constantly adjust everything and flatten out my A/F curve I'll be happy.
An EMS isn't money wasted. Even someday when I decide to dump tons of cash to go FI, I can still make use of it and probably have more control than the standard piggybacks/engine managment systems the FI kits come with.
For some reason I seem to recall that the nissan NA team's Z's have around 380 crank hp. They're limited in the things they can change for the class they race in, but they do have a Motec ECU - which is probalby the best, most expensive, and most involved EMS out there.
I have no idea how well it'll work out, but if the "nissan engineer" is right, maybe an EMS is not a bad 1st mod if you can gain 33 crank hp with it on a stock Z.
it's all speculation. This car is not user friendly in even the slightest for power mods - not even FI. The engine isn't made for FI. Problem is we all like the car and nissan isn't going to help us out on our quest to modding it.
I think TS and AAM flashes do exactly what they say they'll do. They add more power, and balance the A/F better. But we're misled by our own assumptions into thinking it'll solve all the issues. They're adjusting the ignition/fuel mappings, not all the sensor parameters - that I know of. Maybe one of them can jump in and say exactly what they modify when they do flashes.
Last edited by sentry65; 05-09-2005 at 05:55 PM.
05-09-2005, 06:09 PM
#17
Registered User
Join Date: Feb 2003
Location: central ny
Posts: 1,703
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by sentry65
I have no idea how well it'll work out, but if the "nissan engineer" is right, maybe an EMS is not a bad 1st mod if you can gain 33 crank hp with it on a stock Z.
05-09-2005, 06:57 PM
#18
Originally Posted by sentry65
I was assuming, if by pulling timing, the engine will draw less air into it since it won't be as powerful.
If it doesn't suck as much air in because it now has less suction power, it'll get the MAF to reduce it's voltage
If it doesn't suck as much air in because it now has less suction power, it'll get the MAF to reduce it's voltage
your statement about the O2 sensors is confusing me a little. I was thinking like what you are saying in that as long as the A/F and MAF voltage is within stock specs, that the O2 sensors would be happy reguardless if you're making 287 crank hp or 2000 hp passing by the sensor.
If you do something to add more fuel, the O2 sensors report a richer mix (which is bad for emissions) and report it to the ECU. The ECU sees this and decides it needs to start cutting fuel to lean things out until it's within stock emissions specs again.
and yeah, I don't know if the ECU actually has a limitation in itself, but I do think I read that the stock 290cc injectors are barely adequate for over 300 (or was it 320) crank hp for any use of time at WOT. Also the stock fuel pump is close to maxed out too.
thanks for your post, I don't know so much about FI tuning on the Z and all the details, I've kinda been making some assumptions and hoping others would correct me.
Ultimatly, I think the only way to fix the ECU is to basically bypass it with an EMS. And the only way to get past the fuel system is to upgrade to a return system and upgrade the fuel pump and injectors, then tune...
05-09-2005, 07:13 PM
#19
yeah, my car did 281 whp on my last dyno in AZ on 91 octane at around 1500 ft above sea level.
If I wasn't running 1 step colder plugs, I'd make a few hp more I'd guess.
Also my car is misfiring. It didn't start happening until after my TS flash. I've sent it back to them 3 or 4 times and they say there isn't anything they can do about it and that multi misfiring is in fact common on this car with their flash...
So I have to reset the computer all the time. It drives great when it's reset. But as soon as the SES light comes on, it SUCKS to drive - wants to stall, less power, more jittery throttle response, etc etc
TS told me to try 1 step colder plugs, but that didn't help anything other than make me lose some power. Apparently my engine is not misfiring when the ECU is reset, but does so after it gives the SES light. That's suspicious to me. The ECU is doing something to cause it and I bet it's cause I don't meet the expected emissions or MAF voltage and don't have enough fuel going into the engine. So I'm pretty sure I need to upgrade my fuel system, find a way to control my MAF voltage, and get the O2 sensors under control. Only simple way to do that is an EMS with the non-fouler O2 sensor tweak that I can see.
that's my experience...
If I wasn't running 1 step colder plugs, I'd make a few hp more I'd guess.
Also my car is misfiring. It didn't start happening until after my TS flash. I've sent it back to them 3 or 4 times and they say there isn't anything they can do about it and that multi misfiring is in fact common on this car with their flash...
So I have to reset the computer all the time. It drives great when it's reset. But as soon as the SES light comes on, it SUCKS to drive - wants to stall, less power, more jittery throttle response, etc etc
TS told me to try 1 step colder plugs, but that didn't help anything other than make me lose some power. Apparently my engine is not misfiring when the ECU is reset, but does so after it gives the SES light. That's suspicious to me. The ECU is doing something to cause it and I bet it's cause I don't meet the expected emissions or MAF voltage and don't have enough fuel going into the engine. So I'm pretty sure I need to upgrade my fuel system, find a way to control my MAF voltage, and get the O2 sensors under control. Only simple way to do that is an EMS with the non-fouler O2 sensor tweak that I can see.
that's my experience...
05-09-2005, 07:17 PM
#20
Registered User
Join Date: Feb 2003
Location: central ny
Posts: 1,703
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by kcobean
Well, the folks at Turbonetics have figured out how to reprogram the ECU in this car so that their S/T kit is delivering 380-ish WHP with no other form of EMS than the re-flash, so it is tuneable to realize gains. There are a few guys here on the boards who claim to be up in the 270 range with only N/A mods, and I don't know that any of them are running a full EMS.
For example the peak whp for my stock Z is 244@5600rpm (just making something up). Lets pick one rpm value to keep it simple. Power delivery in terms of whp on my Z on a given day may be between 228-244 just at that given rpm, due to the many factors that have been listed previously. The Turbonetics S/T might behave the same way just with higher whp numbers, since there is no engine management system. So the fuel maps are different, but the car might still retard timing...
Bah, I know nothing about enignes/ECUs/etc...who knows. One thing I do know is that this is very unnecessary and frustrating.
Last edited by phile; 05-09-2005 at 07:20 PM.