Im thinking about changing my mind about fuel management for what must be the 5th time.
This round: Greddy E-Manage
So yeah, I've been doing a lot of reading about it, and I have a few things Id like to clarify if I could about the tuning process.
1. Its my understanding that the e-manage changes ONLY the MAFS voltage (or I suppose the combined mafs + pressure sensor settings) for the stock ECU. It is through this (and a translation with injector sizes) that it is able to "trim" injector pulsewidth.
Doesnt this lead to a kinda funky way of tuning? In order to add fuel, you have to effectively "add air" (or at least tell the stock ECU that more air is coming in), then the STOCK ECU performs its own calculations and figures out how much fuel you need based on some algorithm or another.
I suppose it might not be that complicated-- probably something you get used to -- but I just dont understand how you're supposed to do this with no base map besides the stock one in the stock ECU. Are you supposed to just rev it up slowly, making what boost you may, and add fuel as you go? Is that how tuning usually works?
If that's so, how do you deal with timing? Can you pretty much just do everything by RPM? So you're ALWAYS boosting the same amount at the same RPM? That doesnt sound right...
Sigh... the e-manage sounds like it does everything I want it to, but I'm a little bit turned around with the way this works (if you cant tell already). I'd really appreciate it if some of you more experienced guys could either lay this out for me or at least point me in the direction of something to read.
greddy e-manage tuning
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TrunkMonkey
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Checkered-Member
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The E-Manage combined with the supporting tool the ignition harness and the injectors harness, you will be able to control fuel delivery with individual injectors, create fuel maps and control ignition timing.
That said, The e-manage works like a S-AFC, it taps into the wires going in to your stock ECU from the various sensors in your engine (Not just the MAF), and alters the signal, making your ECU do certain things, like retard timing adjust fuel delivery, air to fuel ratio and so on. You are basically controlling your ECU.
That said, by actually tuning your car you will need either a dyno or a Wide Band O2 sensor, personally I’m going with the second option.
That said, The e-manage works like a S-AFC, it taps into the wires going in to your stock ECU from the various sensors in your engine (Not just the MAF), and alters the signal, making your ECU do certain things, like retard timing adjust fuel delivery, air to fuel ratio and so on. You are basically controlling your ECU.
That said, by actually tuning your car you will need either a dyno or a Wide Band O2 sensor, personally I’m going with the second option.
yeah Checkered-Member, I got all that... Just finished reading both owners manuals.. that cleared up a lot of stuff.
So the 16 x 16 map, the peramaters are throttle position and RPM? That way, you can assign a pulsewidth and timing value for WOT (or whatever % throttle position) at any RPM?
I'm just a little confused as to how the actual tuning process works.. it doesnt seem like you're ever going to be able to maintain a specific cell on the tuning chart long enough to get a A/F value to interpret. I mean, say you want to test 37% throttle at 3500 RPM. Thats going to be a hard spot to find, since the RPMS will always be climbing, etc, etc...
Although I guess thats where the benefit of a wideband that datalogs comes in. You can do WOT runs say per 500 rpm, and graph out the A/F ratios... then fine tune from that. It seems like it'd take a long time, but interesting nonetheless.
<does all this sound correct so far?>
next is figuring out the timing curve..
So the 16 x 16 map, the peramaters are throttle position and RPM? That way, you can assign a pulsewidth and timing value for WOT (or whatever % throttle position) at any RPM?
I'm just a little confused as to how the actual tuning process works.. it doesnt seem like you're ever going to be able to maintain a specific cell on the tuning chart long enough to get a A/F value to interpret. I mean, say you want to test 37% throttle at 3500 RPM. Thats going to be a hard spot to find, since the RPMS will always be climbing, etc, etc...
Although I guess thats where the benefit of a wideband that datalogs comes in. You can do WOT runs say per 500 rpm, and graph out the A/F ratios... then fine tune from that. It seems like it'd take a long time, but interesting nonetheless.
<does all this sound correct so far?>
next is figuring out the timing curve..
fiznat wrote:True enough, but the SMT6 also costs 3 times as much. Thats like comparing a S-AFC to a full Haltech system... its just not fair.
The SMT6 is the piggyback system offered by Perfect Power. Their standalone ecu is called the PRS.I am running an SMT6, that's why i recommend it so much.If you get it from the canadian dealer, it won't be as expensive as the e manage.
And FYI, an S-AFC II here in australia retails for around the $650AUD mark. The SMT6 retails around the $600AUD mark.One particular dealer however wanted nearly $1k AUD!!!
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C-Kwik
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Re: greddy e-manage tuning
The E-Manage is does mostly nothing more than fool the ECU. It alters the MAF voltage in the same way those that hack their MAF change the voltage for the actual airflow present. If you run larger injectors, it will make the ECU think the motor is getting less air and therefore the ECU will provide a shorter injector pulsewidth.
As far as tuning, a dyno with a wideband is probably best. Most tuning outside of WOT will almost be useless from altering the MAF signal alone. The ECU will use the closed-loop feedback and adjust the injector signal to provide the set ratio given the TPS, MAF and RPM signals. At WOT, the ECU goes into open-loop and ignores the O2 sensor so no corrections will be made by the ECU at WOT. With the injector harness, it's supposed to be able to add additional injector pulse by providing a ground for the injector. I'm not sure how well this works, but should be good for tuning in closed-loop if it runs too lean. I'm not sure if it causes any issues with the ECU. I speculate that Greddy added this feature for this specific purpose so I'm guessing it will work.
For any proper tuning across the entire mapping, you should typically add an adjustable throttle stop to allow you to hold the throttle against the stop and varying throttle positions and tune at each position. This would give you the most optimal results at all TPS and RPMs. Unfortunately, this can add up to a lot of dyno time. And you usually start out tuning a little rich and lean out as opposed to trying to start lean and richen the mixture as you tune. For low to moderate boost, you can probably get away with some less than perfect tuning. I only used the injector correction factor and also backed off timing at higher airflow rates. No other fuel tuning was done. I run 6.5 psi.
Timing is adjusted in degrees based on airflow meter signal and RPM. It does not tune the actual timing, but rather changes the base timing by the input timing. So if you put -5 degrees timing, then it will back timing off by -5 degrees.
As far as tuning, a dyno with a wideband is probably best. Most tuning outside of WOT will almost be useless from altering the MAF signal alone. The ECU will use the closed-loop feedback and adjust the injector signal to provide the set ratio given the TPS, MAF and RPM signals. At WOT, the ECU goes into open-loop and ignores the O2 sensor so no corrections will be made by the ECU at WOT. With the injector harness, it's supposed to be able to add additional injector pulse by providing a ground for the injector. I'm not sure how well this works, but should be good for tuning in closed-loop if it runs too lean. I'm not sure if it causes any issues with the ECU. I speculate that Greddy added this feature for this specific purpose so I'm guessing it will work.
For any proper tuning across the entire mapping, you should typically add an adjustable throttle stop to allow you to hold the throttle against the stop and varying throttle positions and tune at each position. This would give you the most optimal results at all TPS and RPMs. Unfortunately, this can add up to a lot of dyno time. And you usually start out tuning a little rich and lean out as opposed to trying to start lean and richen the mixture as you tune. For low to moderate boost, you can probably get away with some less than perfect tuning. I only used the injector correction factor and also backed off timing at higher airflow rates. No other fuel tuning was done. I run 6.5 psi.
Timing is adjusted in degrees based on airflow meter signal and RPM. It does not tune the actual timing, but rather changes the base timing by the input timing. So if you put -5 degrees timing, then it will back timing off by -5 degrees.
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C-Kwik
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fiznat wrote:yeah Checkered-Member, I got all that... Just finished reading both owners manuals.. that cleared up a lot of stuff.
So the 16 x 16 map, the peramaters are throttle position and RPM? That way, you can assign a pulsewidth and timing value for WOT (or whatever % throttle position) at any RPM?
I'm just a little confused as to how the actual tuning process works.. it doesnt seem like you're ever going to be able to maintain a specific cell on the tuning chart long enough to get a A/F value to interpret. I mean, say you want to test 37% throttle at 3500 RPM. Thats going to be a hard spot to find, since the RPMS will always be climbing, etc, etc...
Although I guess thats where the benefit of a wideband that datalogs comes in. You can do WOT runs say per 500 rpm, and graph out the A/F ratios... then fine tune from that. It seems like it'd take a long time, but interesting nonetheless.
<does all this sound correct so far?>
next is figuring out the timing curve..
The three most basic maps are the Airflow adjustment, Timing adjustment and the Additional injection maps. The Airflow Adjustment maps are altered based on the TPS and RPM signals. The Timing and additional injection maps are based on Airflow meter voltage and RPM.
The adjustable throttle stop is what you would use as I've mentioned before. Essentially this allows you to maintain the motor at say 30% throttle and tune at each RPM increment on a dyno consistently until you are happy with the results. Then you change the throttle stop to say 35% and do it over again. Properly tuning the entire mapping can be tedious.
From my understanding, tuning the timing curve is like tuning anything else, except the best way is to use a 4-gas analyzer. Not sure how exactly that works and what to look for, but I've heard it in various tuning circles. Kind of a wide-band O2 equivalent for timing.
c-kwik, thanks for the info
hm, that's alot to think about. lemmie try to break it up.
1. the idea of tuning only at WOT to keep the ECU in open loop mode: isnt this going to really limit our ability to tune this setup? I mean, I suppose we could hit most cells by simply opening up the throttle starting at each RPM (or by 500 rpm increments or whatever), but there are bound to be points we miss... although I suppose at that point you can always fill in the holes with averaged numbers... still, it seems less than ideal.
2. grounding out the injector to provide extra pulsewidth seems like it might be a valid technique, but what about times when you want to reduce the amount of fuel sprayed? I dont know if this ever comes up, but how does the e-manage deal with this situation? ...reducing the MAF voltage?
3. Not sure whatcha mean about the timing. I admit this is my first real experience with this kinda stuff, so bear with me.. whats the difference between "tuning the acutal timing" and "changing the base timing?
hm, that's alot to think about. lemmie try to break it up.
1. the idea of tuning only at WOT to keep the ECU in open loop mode: isnt this going to really limit our ability to tune this setup? I mean, I suppose we could hit most cells by simply opening up the throttle starting at each RPM (or by 500 rpm increments or whatever), but there are bound to be points we miss... although I suppose at that point you can always fill in the holes with averaged numbers... still, it seems less than ideal.
2. grounding out the injector to provide extra pulsewidth seems like it might be a valid technique, but what about times when you want to reduce the amount of fuel sprayed? I dont know if this ever comes up, but how does the e-manage deal with this situation? ...reducing the MAF voltage?
3. Not sure whatcha mean about the timing. I admit this is my first real experience with this kinda stuff, so bear with me.. whats the difference between "tuning the acutal timing" and "changing the base timing?
SSS wrote:The SMT6 is the piggyback system offered by Perfect Power. Their standalone ecu is called the PRS.
lol whoops! my fault! haha. Ive been lookin at this for the past couple minutes - downloaded the software like you suggested also. This looks pretty similar to the greddy deal- although I noticed the tuning maps dont have as high of a resolution. I donno, I'm still figuring out the basics for these wanna-be standalone piggyback dealeys. good call though!
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C-Kwik
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Just looked up the SMT6. Appears to be pretty good, but there are trade-offs just as there is with the E-Manage. The SMT6 has only half the resolution the E-Manage does. In direct comparison the E-Manage, the E-Manage has several advantages for supported applications of the E-Manage. The E-Manage allows one to swap MAF's of a supported application with one from another supported application without having to re-tune the map. It will automatically adjust all the maps once you choose the correct MAF. It doesn't look like the SMT6 has an injector correction feature either. I didn't read through the manual though so feel free to correct me if I'm wrong.
The SMT6 has a very distinct advantage though. The ability to alter the Lamda(O2) signal. This would make tuning part throttle much easier as the ECU will not be fighting the stand-alone.
Either should be pretty good as a piggy-back. There's only so much a piggy-back can do anyways.
The SMT6 has a very distinct advantage though. The ability to alter the Lamda(O2) signal. This would make tuning part throttle much easier as the ECU will not be fighting the stand-alone.
Either should be pretty good as a piggy-back. There's only so much a piggy-back can do anyways.
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C-Kwik
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fiznat wrote:c-kwik, thanks for the info
hm, that's alot to think about. lemmie try to break it up.
1. the idea of tuning only at WOT to keep the ECU in open loop mode: isnt this going to really limit our ability to tune this setup? I mean, I suppose we could hit most cells by simply opening up the throttle starting at each RPM (or by 500 rpm increments or whatever), but there are bound to be points we miss... although I suppose at that point you can always fill in the holes with averaged numbers... still, it seems less than ideal.
2. grounding out the injector to provide extra pulsewidth seems like it might be a valid technique, but what about times when you want to reduce the amount of fuel sprayed? I dont know if this ever comes up, but how does the e-manage deal with this situation? ...reducing the MAF voltage?
3. Not sure whatcha mean about the timing. I admit this is my first real experience with this kinda stuff, so bear with me.. whats the difference between "tuning the acutal timing" and "changing the base timing?
1. You can tune at part throttle, but my point was actually that the ECU will want to adjust it according to the O2 sensor feedback. This will be most detrimental in high boost applications where part throttle can still boost fairly high and the feedback may cause a condition that might be somewhat leaner than safe or optimal. But this is where the additional injection map might be able to help. I'm not sure the ECU can fight this since the E-Manage provides the ground to hold the injector open longer. As far as between increments, the E-Manage autmotically calculates the tuning between one increment to the next in a straight line between them. So if you were to plot each point on a graph, then connect each point with a line(connect the dots) you'll end up with your tuning map. And with the E-Manage, you can set your increments manually. So you can actually use a higher resolution mapping at higher RPMs and use a lower resolution at lower RPMs. In other words, you can space tuning increments at every 1000 RPM's up to 3000 RPM, and then maybe every 250 RPM beyond that. Just as an example.
2. To lean it out, you would have to adjust the airflow signal to make the ECU think it's not getting as much air. But as with above, the O2 feedback may cause it to run the ECU's A/F ratio at the given inputs. But I'd be more concerned with running to lean than too rich.
3. Tuning the actual timing would mean that if you set the timing at 20 degrees at WOT at 5000 RPM, then it would be at 20 degrees. Tuning against the base map means that if the ECU puts the motor at 20 degrees at WOT at 5000 RPM and you input 5 degrees into the tuning map, it increases it to a total of 25 degrees.
C-Kwik: Tuning a new MAF can be done with the SMT6, it just isn't as 'point and click' as the e-manage is. What it loses in resolution it makes up for in the ability to select which areas you want the highest resolution to be when you calibrate the TPS position/RPM set points in the calibration menu.For my setup, i will be utilizing the injector map for increased fuelling via 4 auxillary injectors tapped into each runner, and keeping with the stock injectors for idle/low throttle off boost driving. I also can tune for 2 different boost levels and flick between the 2 maps on the go.
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C-Kwik
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Yeah, the E-Manage can support other MAF's the same way too, but it's just a very nice feature to be able to upgrade with relative ease. And as I said, you can choose the tuning points on the map on the E-Manage as well.
As far as tuning for different boost levels, any stand-alone or piggy-back should be able to do that. Just make sure the scale is high enough. If you can support two maps though, it could be used to map out yuor everyday fuel and have a separate map for race gas. That could be far more effective than to try and tune for two different boost levels on the same fuel. Though, with the E-01, I believe you can store a few maps with easy access. The E-01 can vary boost based on RPM when used with an E-Manage as well.
Not trying to make this an E-Manage vs SMT6 pissing match. Both have certain advantages over the other. Each person will need to decide what is best for them. Good stuff.
As far as tuning for different boost levels, any stand-alone or piggy-back should be able to do that. Just make sure the scale is high enough. If you can support two maps though, it could be used to map out yuor everyday fuel and have a separate map for race gas. That could be far more effective than to try and tune for two different boost levels on the same fuel. Though, with the E-01, I believe you can store a few maps with easy access. The E-01 can vary boost based on RPM when used with an E-Manage as well.
Not trying to make this an E-Manage vs SMT6 pissing match. Both have certain advantages over the other. Each person will need to decide what is best for them. Good stuff.
I guess this is more of a general tuning question than e-manage specific, but:
When youre tuning based off of RPM and not a MAP sensor, how are you supposed to be able to account for different boost pressures at different RPM ranges? I assume that youre never going to make exactly the same boost at exactly the same RPM (like when you shift at say 5500 and you're making 10psi, but then you're at a different RPM still pushing close to the same pressure...) it just doesnt seem like boost will always be exactly corrliated with RPM... get what Im sayin? If that's true, how does it help to add fuel at say 4300 RPM and 50% throttle when you dont really know how much fuel you're going to need at that point exactly.
Maybe I'm just thinking of this wrong - if so then please correct me - but otherwise how do you account for this?
When youre tuning based off of RPM and not a MAP sensor, how are you supposed to be able to account for different boost pressures at different RPM ranges? I assume that youre never going to make exactly the same boost at exactly the same RPM (like when you shift at say 5500 and you're making 10psi, but then you're at a different RPM still pushing close to the same pressure...) it just doesnt seem like boost will always be exactly corrliated with RPM... get what Im sayin? If that's true, how does it help to add fuel at say 4300 RPM and 50% throttle when you dont really know how much fuel you're going to need at that point exactly.
Maybe I'm just thinking of this wrong - if so then please correct me - but otherwise how do you account for this?
Thats what the MAF is for, it reads the exact amount of air coming into the engine and calculates the fuel needed from that. To a degree, thats now JWT gets away with doing tunes just for specific components (ie: turbocharged, 72# injectors, and Z32 MAF). It just plain doesn't matter what the boost pressure is because the ECU can figure out the rest. At least, this is how I understand it.
but isnt the intake of the engine affected by both volume AND pressure? I mean, I guess the MAF will see air being sucked in faster cause the turbo is taking it in like that, but it still has no way of calculating the density of the air that is taken in per stroke... I think that's whats gonna count, when you need to decide how much fuel you need. I guess I must be wrong somewhere, because this system DOES work for some people... I just cant seem to figure how tuning with these peramaters enables you to know how much fuel you need at any instant in time. If boost isnt directly coorliated with RPM, or MAF voltage isnt directly coorlated with the volume (and density) of the actual intake charge, I dont see how this system can be effective across the RPM range and through different gears and loads.
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C-Kwik
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Actually the MAF does account for density. The key to this is Mass. A larger amount of mass can always absorb more heat more quickly than a smaller amount of mass of the same material. That being said, if a denser charge of air moves across the hotwire at the same speed, it is exposing more mass if air to the hot wire. This heavier mass will take away more heat. The ECU must compensate by increasing the voltage to the wire to maintain the hotwire temp. The ECU uses this required voltage to calculate how much air is going into the motor.
Consequently, a MAF is much easier to use to determine the actual airflow. Given the same MAF on two different motors, the same voltage reading would correspond fairly close to the same fuel requirements, regardless of displacement, the number of cylinders, RPM, etc. To reach a particular A/F ratio, given a certain intake of air, you inject the the same amount of fuel(volume).
So based on this fact, it is quite easy to calculate the injector pulses needed to provide a sufficient amount of fuel for the given amount of airflow. The various other sensors are used to make adjustsments based on load. As an example, you can run a leaner mixture during cruising, but at WOT, you would want to run a bit richer.
MAP sensors measure pressure, both positive and negative. Then using the TPS, temp and RPM, it calculates what the mass airflow. The VE and of the motor at it's various TPS and RPM's must be known along with the displacement for the motor in order to calculate the mass flow of air. In other words, you can not tell how much air is going into the motor by only knowing the manifold pressure.
As far as boosting, in order for the intake between the Motor and the turbo to have a certain pressure and airflow, it has to pull a certain amount of air through the MAF. The higher pressure and/or higher airflow, the more air has to be drawn through the turbo and consequently the MAF.
Consequently, a MAF is much easier to use to determine the actual airflow. Given the same MAF on two different motors, the same voltage reading would correspond fairly close to the same fuel requirements, regardless of displacement, the number of cylinders, RPM, etc. To reach a particular A/F ratio, given a certain intake of air, you inject the the same amount of fuel(volume).
So based on this fact, it is quite easy to calculate the injector pulses needed to provide a sufficient amount of fuel for the given amount of airflow. The various other sensors are used to make adjustsments based on load. As an example, you can run a leaner mixture during cruising, but at WOT, you would want to run a bit richer.
MAP sensors measure pressure, both positive and negative. Then using the TPS, temp and RPM, it calculates what the mass airflow. The VE and of the motor at it's various TPS and RPM's must be known along with the displacement for the motor in order to calculate the mass flow of air. In other words, you can not tell how much air is going into the motor by only knowing the manifold pressure.
As far as boosting, in order for the intake between the Motor and the turbo to have a certain pressure and airflow, it has to pull a certain amount of air through the MAF. The higher pressure and/or higher airflow, the more air has to be drawn through the turbo and consequently the MAF.
fiznat wrote:but isnt the intake of the engine affected by both volume AND pressure? I mean, I guess the MAF will see air being sucked in faster cause the turbo is taking it in like that, but it still has no way of calculating the density of the air that is taken in per stroke... I think that's whats gonna count, when you need to decide how much fuel you need. I guess I must be wrong somewhere, because this system DOES work for some people... I just cant seem to figure how tuning with these peramaters enables you to know how much fuel you need at any instant in time. If boost isnt directly coorliated with RPM, or MAF voltage isnt directly coorlated with the volume (and density) of the actual intake charge, I dont see how this system can be effective across the RPM range and through different gears and loads.
thats a common misconception. no matter the boost pressure, the engine is only moving a specific VOLUME of air at a given RPM.
the pressure may be different, as will mass, but the volume is always constant at a given rpm.
also, the maf is reading MASS, not volume. mass is what is important, because the fuel is rationed according to mass.
12-14 parts air to 1 part fuel by MASS.
the MAF [hotwire in particular] accounts for density changes due to temperature or pressure. it tells the ecu what the MASS of air entering the system is.
the mass of air entering the motor is directly proportional to the amount of fuel that needs to be burned. that why altering the maf signal is so effective.
also, the throttle opening is just telling the e-manage [and ECU] what kind of load the engine is under. weither its cruising or hard acceleration.
12-14 parts air to 1 part fuel by MASS.
the MAF [hotwire in particular] accounts for density changes due to temperature or pressure. it tells the ecu what the MASS of air entering the system is.
the mass of air entering the motor is directly proportional to the amount of fuel that needs to be burned. that why altering the maf signal is so effective.
also, the throttle opening is just telling the e-manage [and ECU] what kind of load the engine is under. weither its cruising or hard acceleration.