mrlilguy157
Member
- :
- 07 mazdaspeed 3
I'd like to request this as a sticky item.
First off, don't even start reading this stuff unless you have a solid 30-45minutes to devote to it. Get ready to think.
Holy cow guys, piggybacks are obviously not an effective way of tuning these cars, but they are indeed the only options at this point.
Cobb for the win at the moment, hopefully that is proven beneficial. As theyve stated publically before, throttle control is not something that is NEEDED.
Any company that is looking into tuning these cars or squeezing more performance out of them needs to forget about throttle plate control, AFRs at this point, and injector timing, and go back to square 1, and figure the sole purpose of direct injection technology - other than the general facts of 'environmentally friendly', a 'cooler (temperature) combustion chamber', and 'higher compression ratios'.
A famous quote we all know, You dont know where youre going, unless you know where youve been. Tuning these DI cars like a port injection car is not possible. They dont function the same, they were not designed the same. They have different goals and drastically different technologies. All of the data and documents Ive scrounged up seem to be a pretty informative overall.
I'm no programmer, but as far as I can tell, the simplest changes need to be made once the ECU is able to be modified directly.
1. Boost Level (through factory boost solenoid)
2. Commanded AFR (12:1 when possible - not everywhere)
3. Timing Map changes (conservative, aggressive, and 100oct race mode, as well as custom tunability for dyno/custom tuning and extreme setups)
1) With these 3 changes being directly related to the ECU, without a damn piggyback, the ECU can utilize the full 2bar MAP sensor to read up to 29.4psi, and adjust boost accordingly with the solenoid controlling the wastegate. The ECU knows the real level of boost pressure, no tricking. Tricking the ECU doesnt work as effectively. The car freaks out and goes closed loop. By allowing the ECU to truly see everything, it can perform all of its changes NATIVELY.
2) The commanded AFR can be obtainable with the upgraded pump for sure, at most points. No person will run out of fuel above 4k, and below it, I'm not concerned with the AFR's whatsoever - in all honesty. Reading through these articles, youll see relatively new technology and terms, such as ultra-lean burn technology, or lean-burn engines. These terms and ideas are directly related to the direct injection motors. Even being lean in the bottom end, Paleriders graphs (most recent dynos, with the new pump) still could not obtain the 12:1 AFR that most port injection cars desire when upgrading.
Further looking at the graph, when wide open throttle is applied, he was seeing maybe 500rpms of dangerously lean conditions (16:1 dropping to 14.7:1 (stoich)), at a rather low RPM, which is expected with the cam driven fuel pump. Also, in the bottom end, I wouldnt consider this tiny lean spot too much of an issue there isnt enough air flowing nor is the motor working hard enough for something devastating to happen (IMHO). Those readings are also based off of the sniffer, which pushes the AFR UP in the power band. In actuality, the lean spot is even lower.
And Ill quote myself from another thread in responses to Jordan from CP-E, pertaining to this chart that I made as well:
Note: I edited a few things for clarity in that last section
3) The timing adjustments would allow to retard ignition timing for the big turbo guys, but the stock ECU has an INCREDIBLY conservative timing table. Thats why you're not even messing with it with the StandBack unit with the stock turbo users (majority of standback users). Laloosh didnt play with timing grids, and neither does/did dada a few months ago. He came out and said that increasing the timing by 2 additional degrees yielded about 3hp gain, and it wasnt worth it, for the risk factor.
Moving on:
Here are some excerpts from articles and patent documents I've been reading. I'm freaking excited. A lot of this stuff is nerd talk, some of it over my head at this point
My comments about the ECU using the throttle to regulate boost pressure are also mentioned in this stuff. What the hell? The current tuners have no idea what they're getting into as far as I'm concerned, or maybe they do, I don't know, but I feel as if the current progress being made is completely pointless. In my opinion, the Xede and Standback are heading down the wrong highway, Cobb is doing the right thing though, and I completely understand why they have no software out and they are only guaranteeing their tunes with their bolt-on mods. By tuning the ECU directly in relation to all of their mods on their test car, the algorithms modified and the maps created may not act well with different modifications. Sure, the ECU has its built in room for play in the tunes, but really how much play is there? How much correction can the ECU do given that there are literally dozens of variables which come in to play? Cobbs user tunable software is going to be pretty advanced, and need tons and tons of control over everything. A well qualified tuner is going to have to play with this stuff. For simple input fields, like a 30x30 grid of timing modifications, there is going to be A LOT of calculating behind the scenes in order for everything that relates to why the stock ECU would change timing, to still be functional.
As Jordan and I have been discussing in mazdas247, and further ProtegeGarages forum, (GT3071r Thread, pages 8,9, and 10 IIRC), the ECU goes into closed loop when injecting a ridiculous amount of fuel in the bottom. Sure, the upgraded fuel pump has ability to keep the fuel supply going at the right pressures, but does the ECU know that? Well, thats a loaded question. A piggyback for the ms3 isnt controlling the injector pulsewidth vs the pump solenoid together to keep parameters under spec, therefore the ECU goes closed loop. Someone hurry up and crack these ECUs, or come out with a true standalone. That would make this all the much easier.
This further goes back to my belief that piggybacking the ECU is not a good idea for more advanced tunes. With modifying some things, but leaving other things untouched, the ECU freaks and goes closed loop. Bad news. That means the ECU is resorting back to limp mode, being that its running a guaranteed map which will not cause harm to the car, yet the car is still functional 100%. The sensors are doing next to nothing its in its own safety zone, until the sensors feed the right voltages to the ECU, in which itll open back up and try again. No Atari 2600s here
= ken.
Anywho, check this out:
Abstract info about DI systems:
"A method and system for controlling the air charge in a direct injection spark ignition engine that provides proportional plus integral control in positioning an electronic throttle control valve and an exhaust gas recirculating (EGR) valve in order to compensate for uncertainties in the EGR valve flow area. An adaptation algorithm is used to improve the estimate of in-cylinder flow and throttle open-loop control. "
and claims, as well as other nerdy info:
"1. A method of controlling air charge in a direct-injection, spark-ignition engine having an exhaust gas recirculation (EGR) valve connecting the exhaust manifold and intake manifold of the engine, and an electronically controlled throttle (ETC) valve controlling air flow from the atmosphere to the intake manifold of said engine, comprising a sequence of the following steps:
generating an intake manifold pressure value [solenoid boost level sent] which is indicative of measured intake manifold pressure [MAP sensor]
determining a desired intake manifold pressure value;
determining a desired EGR valve position;
determining a desired ETC [electronic throttle control throttle body] valve position;
adjusting said ETC valve position in accordance with said desired ETC valve position; and
adjusting EGR valve position by an amount that is proportional to the error and the time integral of the error between said actual intake pressure value and said desired intake pressure value.
2. The method as set forth in claim 1 wherein said desired intake manifold pressure value is a function of engine speed, and demanded engine torque.
3. The method as set forth in claim 1 wherein said desired intake manifold pressure value is derived from the following equation:
p1,d =Wcyl,d *T1 /(k0 (N)*N)
where;
Wcyl,d is desired total mass flow rate into the cylinder,
N is engine speed, T1 is intake manifold temperature [note: weve seen how intake air temperature plays with the throttle and timing], and k0 is a calibratable function.
4. The method as set forth in claim 1 wherein the EGR and ETC valve positions are determined in accordance with the following equations:
uegr (k)=uegr,d (k)-kp (p1,d (k)-p1 (k))-ki Z(k)
Z(k+1)=Z(k)+(p1,d (k)-p1 (k))*ΔT"
source
So, really, there is some simple algebraic math equations there, and just by looking at them, and what each variable stands for, you can see how and why the throttle is constantly adjusting and I dont care! Now, if we would like to solve this equation, its not that easy. Weve got 2 variables were solving for. p1,d and k0. .k0 is the secret algorithm based on Fords programming, and the p1,d is the output based on all of the sensors coming into the ECU.
Ill let the ECU do its math like its trained to do.
Moving on to more readings, any person who has taken out the swirl control flapper system in the intake manifold is hurting the projected functions of the ECU.
More stuff: Toyota's GDI system:
The D-4 incorporates a highly optimized combustion chamber: The piston crowns are fitted with a lipped, cup-like formation that focuses the injected air/fuel mixture tightly around the spark plug for maximum burn.
Intake air is drawn through helical ports that create a high degree of horizontal swirl, which Toyota says combines with the lipped combustion chamber to not only maintain highly stable combustion -- a quintessential problem for lean-burners -- but also to stratify the air/fuel mixture.
Additional swirl is promoted with special swirl-inducing high-pressure injectors. The end result is a fuel-rich mixture in the direct vicinity of the spark plug, with extremely lean air/fuel ratios near the cylinder walls.
Now, youll see the mentioning of helical swirl ports, which cause the air going into the engine to sort of be tumbling and spinning around. When the air gets in the cylinder, it is moving around, and fuel is injected, to where there is proper and complete atomization. The DISI head doesnt feature helical ports, I know this because there is a new cylinder head sitting next to me on my dresser. Instead, we do have the swirl flappers built into the intake manifold. As these flappers open and close rather quickly, the swirling motion is created for optimum atomization between the air and fuel.
Source
Okay, so there is 2 nice things right? Well, look at the date of that article - 1996. That was wayy early in the game right? Right - and that technology has only become more complicated as technology has been able to take over, and costs have come down with higher demand from automotive manufactures all over the world. In looking up information for my research paper (over optimizing performance output of an internal combustion engine, of course (yes) ), I have found this article here:
DI Motor
Uh oh, Ford has been using these motors in Austrailian cars? XCORP was founded in 1991??? Its apparent that Ford has been working with these guys. So anyways, thats nice. The DI system has been licensed to Ford and GM, as well as Mercury ( a boat engine manufacturer). Wow, crazy to see that Ford and GM both released their high output turbocharged DI motors within a year of eachother (sarcasm)
And, look at this, too. The special piston designs from 1996-2003 were replaced with the flapper system in the intake manifolds, which cause the air to tumble into the cylinders, the swirl effect, exactly the reasoning for the goofy shaped pistons in the preliminary GDI designs. The usage of swirl valves causes a spinning air movement, like a tornado turned horizontally, rolling like a barrel, which causes atomization of the fuel and air together in the cylinder, instead of the goofy darth vader mask pistons which do the same thing at more $$$ to the manufacture, and more research and design.
Darth Vader
So, in essence, lets stay simple we can if thats even possible with the direct injection technology.
First off, don't even start reading this stuff unless you have a solid 30-45minutes to devote to it. Get ready to think.
Holy cow guys, piggybacks are obviously not an effective way of tuning these cars, but they are indeed the only options at this point.
Cobb for the win at the moment, hopefully that is proven beneficial. As theyve stated publically before, throttle control is not something that is NEEDED.
Any company that is looking into tuning these cars or squeezing more performance out of them needs to forget about throttle plate control, AFRs at this point, and injector timing, and go back to square 1, and figure the sole purpose of direct injection technology - other than the general facts of 'environmentally friendly', a 'cooler (temperature) combustion chamber', and 'higher compression ratios'.
A famous quote we all know, You dont know where youre going, unless you know where youve been. Tuning these DI cars like a port injection car is not possible. They dont function the same, they were not designed the same. They have different goals and drastically different technologies. All of the data and documents Ive scrounged up seem to be a pretty informative overall.
I'm no programmer, but as far as I can tell, the simplest changes need to be made once the ECU is able to be modified directly.
1. Boost Level (through factory boost solenoid)
2. Commanded AFR (12:1 when possible - not everywhere)
3. Timing Map changes (conservative, aggressive, and 100oct race mode, as well as custom tunability for dyno/custom tuning and extreme setups)
1) With these 3 changes being directly related to the ECU, without a damn piggyback, the ECU can utilize the full 2bar MAP sensor to read up to 29.4psi, and adjust boost accordingly with the solenoid controlling the wastegate. The ECU knows the real level of boost pressure, no tricking. Tricking the ECU doesnt work as effectively. The car freaks out and goes closed loop. By allowing the ECU to truly see everything, it can perform all of its changes NATIVELY.
2) The commanded AFR can be obtainable with the upgraded pump for sure, at most points. No person will run out of fuel above 4k, and below it, I'm not concerned with the AFR's whatsoever - in all honesty. Reading through these articles, youll see relatively new technology and terms, such as ultra-lean burn technology, or lean-burn engines. These terms and ideas are directly related to the direct injection motors. Even being lean in the bottom end, Paleriders graphs (most recent dynos, with the new pump) still could not obtain the 12:1 AFR that most port injection cars desire when upgrading.
Palerider said:This one is at 17 psi from today. It also has the upgraded pump.
Further looking at the graph, when wide open throttle is applied, he was seeing maybe 500rpms of dangerously lean conditions (16:1 dropping to 14.7:1 (stoich)), at a rather low RPM, which is expected with the cam driven fuel pump. Also, in the bottom end, I wouldnt consider this tiny lean spot too much of an issue there isnt enough air flowing nor is the motor working hard enough for something devastating to happen (IMHO). Those readings are also based off of the sniffer, which pushes the AFR UP in the power band. In actuality, the lean spot is even lower.
And Ill quote myself from another thread in responses to Jordan from CP-E, pertaining to this chart that I made as well:
mrlilguy157 said:
When it comes to producing power, we want the cars tuned for more fuel in the bottom end, and less fuel in the top end, something closer to stoich (12.8:1 is the highest AFR Ill go in the top end when the car is trucking along) , not 10.5:1 AFR. I also wonder the same question about running the car so lean before 3500rpms, or do I? Doing simple Google searches, GDI systems weren't all about power in the initial designs, before patents were issued. Back in 1997 when Hitachi introduced GDI systems, the main goal was to be more environmentally friendly, being able to run leaner mixtures safely, to make the trees greener and the ozone layer to stay together. Not suprisingly however, being the power-hungry enthusiasts that we are, we enjoy the torque and acceleration.
The graph which I composed was a mixture of data directly from APR and from Autotech. The numbers for the stock hitachi fuel pump were taken directly from APR's site, for they've got the 1 of 3 in the nation CDFP testers at $80,000, and I don't. I took the numbers they have on the chart and then compared the projected HP line of the APR FSI pump upgrade, which is advertised at 42% flow over stock, and verified this with the chart posted for all to see. Then, taking Autotech's data of 50% over stock flow, I created the graph which Jordan posted in his response. That is the only place those numbers have come from, directly from the manufactures, no where else. Yes, there is more flow up top, for its a linear 40% or 52% over stock flow levels, from the bottom to the top, linearly. The increased inner piston diameter across the stroke of the piston in and out of the pump is what allows more fuel in the pump per stroke, creating more pressure at more volume.
I don't know everything about the GDI systems, I'm leaning daily, more and more as I talk with more tuners, companies, testers, and drivers; I hope all of the input provided helps in some way....
Note: I edited a few things for clarity in that last section
3) The timing adjustments would allow to retard ignition timing for the big turbo guys, but the stock ECU has an INCREDIBLY conservative timing table. Thats why you're not even messing with it with the StandBack unit with the stock turbo users (majority of standback users). Laloosh didnt play with timing grids, and neither does/did dada a few months ago. He came out and said that increasing the timing by 2 additional degrees yielded about 3hp gain, and it wasnt worth it, for the risk factor.
Moving on:
Here are some excerpts from articles and patent documents I've been reading. I'm freaking excited. A lot of this stuff is nerd talk, some of it over my head at this point
My comments about the ECU using the throttle to regulate boost pressure are also mentioned in this stuff. What the hell? The current tuners have no idea what they're getting into as far as I'm concerned, or maybe they do, I don't know, but I feel as if the current progress being made is completely pointless. In my opinion, the Xede and Standback are heading down the wrong highway, Cobb is doing the right thing though, and I completely understand why they have no software out and they are only guaranteeing their tunes with their bolt-on mods. By tuning the ECU directly in relation to all of their mods on their test car, the algorithms modified and the maps created may not act well with different modifications. Sure, the ECU has its built in room for play in the tunes, but really how much play is there? How much correction can the ECU do given that there are literally dozens of variables which come in to play? Cobbs user tunable software is going to be pretty advanced, and need tons and tons of control over everything. A well qualified tuner is going to have to play with this stuff. For simple input fields, like a 30x30 grid of timing modifications, there is going to be A LOT of calculating behind the scenes in order for everything that relates to why the stock ECU would change timing, to still be functional.
As Jordan and I have been discussing in mazdas247, and further ProtegeGarages forum, (GT3071r Thread, pages 8,9, and 10 IIRC), the ECU goes into closed loop when injecting a ridiculous amount of fuel in the bottom. Sure, the upgraded fuel pump has ability to keep the fuel supply going at the right pressures, but does the ECU know that? Well, thats a loaded question. A piggyback for the ms3 isnt controlling the injector pulsewidth vs the pump solenoid together to keep parameters under spec, therefore the ECU goes closed loop. Someone hurry up and crack these ECUs, or come out with a true standalone. That would make this all the much easier.
This further goes back to my belief that piggybacking the ECU is not a good idea for more advanced tunes. With modifying some things, but leaving other things untouched, the ECU freaks and goes closed loop. Bad news. That means the ECU is resorting back to limp mode, being that its running a guaranteed map which will not cause harm to the car, yet the car is still functional 100%. The sensors are doing next to nothing its in its own safety zone, until the sensors feed the right voltages to the ECU, in which itll open back up and try again. No Atari 2600s here
= ken.Anywho, check this out:
Abstract info about DI systems:
"A method and system for controlling the air charge in a direct injection spark ignition engine that provides proportional plus integral control in positioning an electronic throttle control valve and an exhaust gas recirculating (EGR) valve in order to compensate for uncertainties in the EGR valve flow area. An adaptation algorithm is used to improve the estimate of in-cylinder flow and throttle open-loop control. "
and claims, as well as other nerdy info:
"1. A method of controlling air charge in a direct-injection, spark-ignition engine having an exhaust gas recirculation (EGR) valve connecting the exhaust manifold and intake manifold of the engine, and an electronically controlled throttle (ETC) valve controlling air flow from the atmosphere to the intake manifold of said engine, comprising a sequence of the following steps:
generating an intake manifold pressure value [solenoid boost level sent] which is indicative of measured intake manifold pressure [MAP sensor]
determining a desired intake manifold pressure value;
determining a desired EGR valve position;
determining a desired ETC [electronic throttle control throttle body] valve position;
adjusting said ETC valve position in accordance with said desired ETC valve position; and
adjusting EGR valve position by an amount that is proportional to the error and the time integral of the error between said actual intake pressure value and said desired intake pressure value.
2. The method as set forth in claim 1 wherein said desired intake manifold pressure value is a function of engine speed, and demanded engine torque.
3. The method as set forth in claim 1 wherein said desired intake manifold pressure value is derived from the following equation:
p1,d =Wcyl,d *T1 /(k0 (N)*N)
where;
Wcyl,d is desired total mass flow rate into the cylinder,
N is engine speed, T1 is intake manifold temperature [note: weve seen how intake air temperature plays with the throttle and timing], and k0 is a calibratable function.
4. The method as set forth in claim 1 wherein the EGR and ETC valve positions are determined in accordance with the following equations:
uegr (k)=uegr,d (k)-kp (p1,d (k)-p1 (k))-ki Z(k)
Z(k+1)=Z(k)+(p1,d (k)-p1 (k))*ΔT"
source
So, really, there is some simple algebraic math equations there, and just by looking at them, and what each variable stands for, you can see how and why the throttle is constantly adjusting and I dont care! Now, if we would like to solve this equation, its not that easy. Weve got 2 variables were solving for. p1,d and k0. .k0 is the secret algorithm based on Fords programming, and the p1,d is the output based on all of the sensors coming into the ECU.
Ill let the ECU do its math like its trained to do.
Moving on to more readings, any person who has taken out the swirl control flapper system in the intake manifold is hurting the projected functions of the ECU.
More stuff: Toyota's GDI system:
The D-4 incorporates a highly optimized combustion chamber: The piston crowns are fitted with a lipped, cup-like formation that focuses the injected air/fuel mixture tightly around the spark plug for maximum burn.
Intake air is drawn through helical ports that create a high degree of horizontal swirl, which Toyota says combines with the lipped combustion chamber to not only maintain highly stable combustion -- a quintessential problem for lean-burners -- but also to stratify the air/fuel mixture.
Additional swirl is promoted with special swirl-inducing high-pressure injectors. The end result is a fuel-rich mixture in the direct vicinity of the spark plug, with extremely lean air/fuel ratios near the cylinder walls.
Now, youll see the mentioning of helical swirl ports, which cause the air going into the engine to sort of be tumbling and spinning around. When the air gets in the cylinder, it is moving around, and fuel is injected, to where there is proper and complete atomization. The DISI head doesnt feature helical ports, I know this because there is a new cylinder head sitting next to me on my dresser. Instead, we do have the swirl flappers built into the intake manifold. As these flappers open and close rather quickly, the swirling motion is created for optimum atomization between the air and fuel.
Source
Okay, so there is 2 nice things right? Well, look at the date of that article - 1996. That was wayy early in the game right? Right - and that technology has only become more complicated as technology has been able to take over, and costs have come down with higher demand from automotive manufactures all over the world. In looking up information for my research paper (over optimizing performance output of an internal combustion engine, of course (yes) ), I have found this article here:
DI Motor
Uh oh, Ford has been using these motors in Austrailian cars? XCORP was founded in 1991??? Its apparent that Ford has been working with these guys. So anyways, thats nice. The DI system has been licensed to Ford and GM, as well as Mercury ( a boat engine manufacturer). Wow, crazy to see that Ford and GM both released their high output turbocharged DI motors within a year of eachother (sarcasm)
And, look at this, too. The special piston designs from 1996-2003 were replaced with the flapper system in the intake manifolds, which cause the air to tumble into the cylinders, the swirl effect, exactly the reasoning for the goofy shaped pistons in the preliminary GDI designs. The usage of swirl valves causes a spinning air movement, like a tornado turned horizontally, rolling like a barrel, which causes atomization of the fuel and air together in the cylinder, instead of the goofy darth vader mask pistons which do the same thing at more $$$ to the manufacture, and more research and design.
Darth Vader
So, in essence, lets stay simple we can if thats even possible with the direct injection technology.
