What is the most HP tuned on stock MAF?
Sep 14, 2007, 04:37 PM
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What is the most HP tuned on stock MAF?
My tuner told me 500awhp is the limit and after that the MAF isn't acurate enough to tune through so I need to go to a stand alone and speed density.
Is this true?
Is this true?
Sep 14, 2007, 04:42 PM
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I made 582. Added buschur 272's. Hopefully with more boost and the additional airflow from the cams, I will get to 650. Ill be on the dyno at Brothers in Tampa tomorrow...
Sep 15, 2007, 05:03 AM
#7
Yep, the limitation of the stock maf is its ability to properly meter the air at such high flow rates.. Big numbers are possible, but its nearly impossible to tune for variations at that point. 500whp is about the limit to where the stock maf can still meter air. Unfortunately over that, the MAF itself starts to suffer from the effects of the airflow (collapsed maf screens, etc..) Any defect in that screen will have aerodynamic affects on itself, or cause additional turbulence in the sensor or other anomolies.
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Sep 15, 2007, 08:34 AM
#8
The yes part:
There are plenty of people now with Evos and plenty of people years ago with DSMs using Evo Mafs that have gone well beyond this mark with a smooth signal.
I remember reading threads on the DSMLink boards with a few people well into the 60lbs/min range and ever one near the 70 lbs/min mark (IIRC) with the Evo MAF. That's roughly 700HP.
By the years of research and testing of the 2G MAF and the known points at which that MAF begin to read erractically and the known compensation values from the 2G to Evo MAF (roughly +25%), the DSMLink crowd knew roughly what the MAF was good to. There calculations figured roughly 62-65 lbs/min (~620-650 HP). As mentioned this has been backed up by a few people on those boards years ago and even past that mark.
The no part:
Even though the sensor itself may be able to read airflows that high, the physical attributes of the part itself may not be structurally sound enough to handle it. There has been a lot of evidence on these boards where the screen has been damaged, being sucked toward the compressor. Some people have reinforced the screens and have good luck.
So, your tuner is right and wrong. The 500 whp mark is a good mark to be safe and ditch the stock MAF. But, the stock MAF sensor can read past that mark and still perform well, given that it will physically hold up.
With Bez's speed density patch, that may be an option soon for a lot of people that want to ditch the stock, once the patch gets ported over to other ROMs.
Eric
Last edited by l2r99gst; Sep 15, 2007 at 08:37 AM.
Sep 15, 2007, 09:09 AM
#10
Ivey is right, but you can see the whp/wtq I made in my signature. I'm thinking of switching to an AEM standalone, but am having trouble finding a bargain. Also, I love the stock drivability of my car, and am really nervous about making compromises on the drivability of my car. That is something that I've always prided myself on maintaining.
Sep 16, 2007, 07:24 AM
#11
Having a standalone always offers more "easier to access and adjust" features than the stock ECU, though that is changing as time passes. The problems running the stock ECU are the limitations imposed by stock sensors, and that is definitely no longer a problem with the alternatives availabled.
Everyone should keep in mind that you have to seperate the capabilities of the stock ECU, from the capabilities of the MAF. Without the stock MAF, the ECU is capable of producing the same power results as a standalone with much better drivability. It takes a long time and weather changes, to reproduce that level of drivability with a standalone.
Those two paragraphs are clearly off-topic for this thread. But I wanted to illustrate that the limitations we're dealing with are really MAF related. It in itself is not really a huge restriction for most applications, but it is a problem when you deal with high airflow rates that are well beyond what it was designed for. Its design is alot like dealing with an airplane wing. You can't expect a propeller engined high performance plane's wings to hold together very long at well beyond the speeds of a jet engined fighter.
The insides of the MAF use several aerodynamic principals to function properly. There is the honeycomb, the sample region (Where the location where the air goes through to be metered) the tube itself..
The honeycomb itself is used to guide the air more precisely through the body, this gives an accurate sample through the meter, which is in proper relation to the total airflow through the entire unit. The honeycomb itself has aerodynamic properties, so defects in the fins will produce turbulence or lift which will of course, deform it. Enough airflow through it, and it will perminently deform (you see that as the crushed screens you periodically see)
The tube has a slight different in size between the inlet and outlet, this will produce a venturi effect where airflow through the sensor is accelerated, the faster the airflow, the more the difference in speed from the outer region to the center region. Imagine the image you get with an hourglass, the center portion of the sand sinks first before the outer. So you have basically a different measurement of airflow through the metered portion in relation to the unmetered portion, and this changes all the time as things change the aerodynamic properties of the honeycomb, intake tube, etc..
Trying to keep this as simple to visualize as possible, but explain why the sensor itself is great for drivability, but not great for engine performance and tuning because it becomes less predictable.
But the short clear answer is the more air you have to move through it, the more of a problem it becomes. The amount of airflow does correlate to some extent to engine horsepower, so 500 whp seems to correlate to that magic level of airflow where things begin to become unpredictable.
Everyone should keep in mind that you have to seperate the capabilities of the stock ECU, from the capabilities of the MAF. Without the stock MAF, the ECU is capable of producing the same power results as a standalone with much better drivability. It takes a long time and weather changes, to reproduce that level of drivability with a standalone.
Those two paragraphs are clearly off-topic for this thread. But I wanted to illustrate that the limitations we're dealing with are really MAF related. It in itself is not really a huge restriction for most applications, but it is a problem when you deal with high airflow rates that are well beyond what it was designed for. Its design is alot like dealing with an airplane wing. You can't expect a propeller engined high performance plane's wings to hold together very long at well beyond the speeds of a jet engined fighter.
The insides of the MAF use several aerodynamic principals to function properly. There is the honeycomb, the sample region (Where the location where the air goes through to be metered) the tube itself..
The honeycomb itself is used to guide the air more precisely through the body, this gives an accurate sample through the meter, which is in proper relation to the total airflow through the entire unit. The honeycomb itself has aerodynamic properties, so defects in the fins will produce turbulence or lift which will of course, deform it. Enough airflow through it, and it will perminently deform (you see that as the crushed screens you periodically see)
The tube has a slight different in size between the inlet and outlet, this will produce a venturi effect where airflow through the sensor is accelerated, the faster the airflow, the more the difference in speed from the outer region to the center region. Imagine the image you get with an hourglass, the center portion of the sand sinks first before the outer. So you have basically a different measurement of airflow through the metered portion in relation to the unmetered portion, and this changes all the time as things change the aerodynamic properties of the honeycomb, intake tube, etc..
Trying to keep this as simple to visualize as possible, but explain why the sensor itself is great for drivability, but not great for engine performance and tuning because it becomes less predictable.
But the short clear answer is the more air you have to move through it, the more of a problem it becomes. The amount of airflow does correlate to some extent to engine horsepower, so 500 whp seems to correlate to that magic level of airflow where things begin to become unpredictable.
Sep 16, 2007, 07:59 AM
#12
^^ Welcome back malibu, you dont post much anymore lol, anyways i think someone said they removed the honey comb and tuned the car to idle and run normal. Smog you should just wait until the map patch is complete for your rom and then you will be able to switch over to map sensor like others are already doing. So far I think 2 or 3 roms have the capability, but I am sure it wont be long until others are able as well.
Sep 16, 2007, 09:50 AM
#13
Very limited resolution, RPM and load wise.
Having to add other ecus to take care of speed density or larger mas air units.
Driveability on the Fcon Pro or AEM or even the Motec system I have done are as good or better than stock ecu, and I can tell you the driveability with the bigger cams sucks on a stock ecu and is way better with speed density.
Tuning a standalone is not a $50 flash tune where you put a block of 7 and call it "tuning", it takes time and a person who knows the system, but there are no limitations and alot more functionality.
The internet is a dangerous thing, and being cheap is another.
I just did an evo 8 with 530 wheel HP yesterday on the dyno with stock maf, did another evo 9 with 568 wheel, and plenty others, but cost is always the factor why they still keep the stock ecu, after a certain point there is no resolution with the stock system and you are using one line of load to set fuel and timing once on boost, it isn't the right way to do it, but you can make hp just very very crude.
Sean
Having to add other ecus to take care of speed density or larger mas air units.
Driveability on the Fcon Pro or AEM or even the Motec system I have done are as good or better than stock ecu, and I can tell you the driveability with the bigger cams sucks on a stock ecu and is way better with speed density.
Tuning a standalone is not a $50 flash tune where you put a block of 7 and call it "tuning", it takes time and a person who knows the system, but there are no limitations and alot more functionality.
The internet is a dangerous thing, and being cheap is another.
I just did an evo 8 with 530 wheel HP yesterday on the dyno with stock maf, did another evo 9 with 568 wheel, and plenty others, but cost is always the factor why they still keep the stock ecu, after a certain point there is no resolution with the stock system and you are using one line of load to set fuel and timing once on boost, it isn't the right way to do it, but you can make hp just very very crude.
Sean
Having a standalone always offers more "easier to access and adjust" features than the stock ECU, though that is changing as time passes. The problems running the stock ECU are the limitations imposed by stock sensors, and that is definitely no longer a problem with the alternatives availabled.
Everyone should keep in mind that you have to seperate the capabilities of the stock ECU, from the capabilities of the MAF. Without the stock MAF, the ECU is capable of producing the same power results as a standalone with much better drivability. It takes a long time and weather changes, to reproduce that level of drivability with a standalone.
Those two paragraphs are clearly off-topic for this thread. But I wanted to illustrate that the limitations we're dealing with are really MAF related. It in itself is not really a huge restriction for most applications, but it is a problem when you deal with high airflow rates that are well beyond what it was designed for. Its design is alot like dealing with an airplane wing. You can't expect a propeller engined high performance plane's wings to hold together very long at well beyond the speeds of a jet engined fighter.
The insides of the MAF use several aerodynamic principals to function properly. There is the honeycomb, the sample region (Where the location where the air goes through to be metered) the tube itself..
The honeycomb itself is used to guide the air more precisely through the body, this gives an accurate sample through the meter, which is in proper relation to the total airflow through the entire unit. The honeycomb itself has aerodynamic properties, so defects in the fins will produce turbulence or lift which will of course, deform it. Enough airflow through it, and it will perminently deform (you see that as the crushed screens you periodically see)
The tube has a slight different in size between the inlet and outlet, this will produce a venturi effect where airflow through the sensor is accelerated, the faster the airflow, the more the difference in speed from the outer region to the center region. Imagine the image you get with an hourglass, the center portion of the sand sinks first before the outer. So you have basically a different measurement of airflow through the metered portion in relation to the unmetered portion, and this changes all the time as things change the aerodynamic properties of the honeycomb, intake tube, etc..
Trying to keep this as simple to visualize as possible, but explain why the sensor itself is great for drivability, but not great for engine performance and tuning because it becomes less predictable.
But the short clear answer is the more air you have to move through it, the more of a problem it becomes. The amount of airflow does correlate to some extent to engine horsepower, so 500 whp seems to correlate to that magic level of airflow where things begin to become unpredictable.
Everyone should keep in mind that you have to seperate the capabilities of the stock ECU, from the capabilities of the MAF. Without the stock MAF, the ECU is capable of producing the same power results as a standalone with much better drivability. It takes a long time and weather changes, to reproduce that level of drivability with a standalone.
Those two paragraphs are clearly off-topic for this thread. But I wanted to illustrate that the limitations we're dealing with are really MAF related. It in itself is not really a huge restriction for most applications, but it is a problem when you deal with high airflow rates that are well beyond what it was designed for. Its design is alot like dealing with an airplane wing. You can't expect a propeller engined high performance plane's wings to hold together very long at well beyond the speeds of a jet engined fighter.
The insides of the MAF use several aerodynamic principals to function properly. There is the honeycomb, the sample region (Where the location where the air goes through to be metered) the tube itself..
The honeycomb itself is used to guide the air more precisely through the body, this gives an accurate sample through the meter, which is in proper relation to the total airflow through the entire unit. The honeycomb itself has aerodynamic properties, so defects in the fins will produce turbulence or lift which will of course, deform it. Enough airflow through it, and it will perminently deform (you see that as the crushed screens you periodically see)
The tube has a slight different in size between the inlet and outlet, this will produce a venturi effect where airflow through the sensor is accelerated, the faster the airflow, the more the difference in speed from the outer region to the center region. Imagine the image you get with an hourglass, the center portion of the sand sinks first before the outer. So you have basically a different measurement of airflow through the metered portion in relation to the unmetered portion, and this changes all the time as things change the aerodynamic properties of the honeycomb, intake tube, etc..
Trying to keep this as simple to visualize as possible, but explain why the sensor itself is great for drivability, but not great for engine performance and tuning because it becomes less predictable.
But the short clear answer is the more air you have to move through it, the more of a problem it becomes. The amount of airflow does correlate to some extent to engine horsepower, so 500 whp seems to correlate to that magic level of airflow where things begin to become unpredictable.
Sep 16, 2007, 09:57 AM
#14
Very limited resolution, RPM and load wise.
Having to add other ecus to take care of speed density or larger mas air units.
Driveability on the Fcon Pro or AEM or even the Motec system I have done are as good or better than stock ecu, and I can tell you the driveability with the bigger cams sucks on a stock ecu and is way better with speed density.
Tuning a standalone is not a $50 flash tune where you put a block of 7 and call it "tuning", it takes time and a person who knows the system, but there are no limitations and alot more functionality.
The internet is a dangerous thing, and being cheap is another.
I just did an evo 8 with 530 wheel HP yesterday on the dyno with stock maf, did another evo 9 with 568 wheel, and plenty others, but cost is always the factor why they still keep the stock ecu, after a certain point there is no resolution with the stock system and you are using one line of load to set fuel and timing once on boost, it isn't the right way to do it, but you can make hp just very very crude.
Sean
Having to add other ecus to take care of speed density or larger mas air units.
Driveability on the Fcon Pro or AEM or even the Motec system I have done are as good or better than stock ecu, and I can tell you the driveability with the bigger cams sucks on a stock ecu and is way better with speed density.
Tuning a standalone is not a $50 flash tune where you put a block of 7 and call it "tuning", it takes time and a person who knows the system, but there are no limitations and alot more functionality.
The internet is a dangerous thing, and being cheap is another.
I just did an evo 8 with 530 wheel HP yesterday on the dyno with stock maf, did another evo 9 with 568 wheel, and plenty others, but cost is always the factor why they still keep the stock ecu, after a certain point there is no resolution with the stock system and you are using one line of load to set fuel and timing once on boost, it isn't the right way to do it, but you can make hp just very very crude.
Sean
With new code and patches being written for the stock ECU, this isn't an issue anymore. There are already a few people running speed density on the stock ECU and there has been live map switching for a while.
New maps can be added to provide whatever resolution you want. Granted this isn't something everyone can do, but new devleopments like this is why the stock ECU is so great. This is basically turning the stock ECU into a standalone, and even better than a standalone, since we can develop new code for the stock ECU to do whatever we wish. With a standalone, you're limited to what their developers give you.
However, the stock ECU development is still in it's infancy at the moment and I agree that a stand-alone may be for some people. But, don't discredit the stock ECU just yet. It's capabilities are endless in the right hands.
Eric
Sep 16, 2007, 09:59 AM
#15
When it's ready and sold in a package that I can transfer to my customers let me know. What is the name of your company by the way? Like I said, functional not experimental.
I need a system that is reliable, tested and functional before I can institute it on my customers cars, the technology is out there right now to do that with the standalone sytems so I see no reason at this point in time to do anything else.
Sean
I need a system that is reliable, tested and functional before I can institute it on my customers cars, the technology is out there right now to do that with the standalone sytems so I see no reason at this point in time to do anything else.
Sean