Do MAFs adjust richer as gears go up? Tuners & members please respond: Truth Squad
Dec 16, 2005, 07:02 PM
#91
[QUOTE=Ted B]
Perhaps that's because I was reprogramming both speed density and mass air systems back when you were still playing with your G.I. Joe? [QUOTE]
Or power rangers
...this almost reminds me of the old sequential vs batch fire chats I used to have
Altitude shifts and cam changes would require my Z to go through some PROM changes. Im using the stock speed density 7730 ECM. I would insert target VE values (VE's vs RPM vs MAP)
The lower VE table goes from 400rpm to 1600 rpm in 100 rpm increments while the upper VE table goes from 1600 to 5600 rpm in 400 increments.
Some one mentioned MAP signal is not engine load...it is. It is represented in my case in kPa. The higher the engine load, the higher the kPa. Think about it this way. When you car is idling it is pulling a vacuum inside the plenum. As you open the throttle blades you are providing an inlet that will decrease the effective vacuum. Here is the often tricky part … LESS vacuum is represented by a HIGHER kPa value. Keep that in mind. Lets say we are driving uphill. You would consider driving uphill to be more of a load on the engine.
If you are driving uphill you probably have your foot more on the gas. If you have the gas pedal depressed more then that means that the throttle blades are opened more. The throttle blades being opened more will result in LESS vacuum and HIGHER kPa value.
So, MAP equals load where increasing load is represented by higher kPa values. When put in context of the VE tables this represents increasing load on the engine.
When taken to the extreme we can view the highest kPa reading (100kPa) to be equal to Wide Open Throttle (WOT). WOT will put the highest load on the engine. 100kPa is atmospheric pressure ... no vacuum at all.
I could keep going :P but there are compensations for temp sensor readings and the such then deal with AIR pump and EGR arrrgggg lol ....bottom line is MAP is not as robust as the MAF but to me, its simple to work and it does work...proven I should say.
TedB is right...MAF shouldnt be a hinderance on 500hp 4g63's.
Perhaps that's because I was reprogramming both speed density and mass air systems back when you were still playing with your G.I. Joe? [QUOTE]
Or power rangers
...this almost reminds me of the old sequential vs batch fire chats I used to have Altitude shifts and cam changes would require my Z to go through some PROM changes. Im using the stock speed density 7730 ECM. I would insert target VE values (VE's vs RPM vs MAP)
The lower VE table goes from 400rpm to 1600 rpm in 100 rpm increments while the upper VE table goes from 1600 to 5600 rpm in 400 increments.
Some one mentioned MAP signal is not engine load...it is. It is represented in my case in kPa. The higher the engine load, the higher the kPa. Think about it this way. When you car is idling it is pulling a vacuum inside the plenum. As you open the throttle blades you are providing an inlet that will decrease the effective vacuum. Here is the often tricky part … LESS vacuum is represented by a HIGHER kPa value. Keep that in mind. Lets say we are driving uphill. You would consider driving uphill to be more of a load on the engine.
If you are driving uphill you probably have your foot more on the gas. If you have the gas pedal depressed more then that means that the throttle blades are opened more. The throttle blades being opened more will result in LESS vacuum and HIGHER kPa value.
So, MAP equals load where increasing load is represented by higher kPa values. When put in context of the VE tables this represents increasing load on the engine.
When taken to the extreme we can view the highest kPa reading (100kPa) to be equal to Wide Open Throttle (WOT). WOT will put the highest load on the engine. 100kPa is atmospheric pressure ... no vacuum at all.
I could keep going :P but there are compensations for temp sensor readings and the such then deal with AIR pump and EGR arrrgggg lol ....bottom line is MAP is not as robust as the MAF but to me, its simple to work and it does work...proven I should say.
TedB is right...MAF shouldnt be a hinderance on 500hp 4g63's.
Last edited by EVOla_VIRUS; Dec 16, 2005 at 07:07 PM.
Dec 16, 2005, 07:06 PM
#92
Well I read the article.... WOW it explained how much better the MAF is About as well as you did. It said it is more accurate and is adaptable... But didnt explain what it can adapt to. It also had a bunch of MAFs that were a resitriction. So... again, I am waiting and will continue to wait for someone to chime in that has an answer as to why a MAF is better in our cases.
Give me ONE credible reason that it CAN do that speed density cant. Just one would be enough but I would like to make it a better alternative you should probably make sure it outweighs the inherit advantages that speed density provides. Your car would need to be reprogrammed to use another MAF anyways, so dont say it is simpler. Dont say its cheaper because thats not the case. Its added accuracy is obviously not needed at all as it is proven with the thousands of cars that run perfectly using speed density.
About as well as you did. It said it is more accurate and is adaptable... But didnt explain what it can adapt to. It also had a bunch of MAFs that were a resitriction. So... again, I am waiting and will continue to wait for someone to chime in that has an answer as to why a MAF is better in our cases.Give me ONE credible reason that it CAN do that speed density cant. Just one would be enough but I would like to make it a better alternative you should probably make sure it outweighs the inherit advantages that speed density provides. Your car would need to be reprogrammed to use another MAF anyways, so dont say it is simpler. Dont say its cheaper because thats not the case. Its added accuracy is obviously not needed at all as it is proven with the thousands of cars that run perfectly using speed density.
Dec 16, 2005, 07:09 PM
#93
We are not saying it SP CANT do the job...cause SD cars does start up when you turn the key, right? lol but its adaptable like the Terminator is...
Edit: adaptable you say...think of it this way.....altitude. As you go up in the air you loose air pressure. Take a car to 4000ft and the computer might think your WOT or something yet your TPS is not even open....speed density says "WTF??" while MAF has the adaptability to over come.
Edit: adaptable you say...think of it this way.....altitude. As you go up in the air you loose air pressure. Take a car to 4000ft and the computer might think your WOT or something yet your TPS is not even open....speed density says "WTF??" while MAF has the adaptability to over come.
Last edited by EVOla_VIRUS; Dec 16, 2005 at 07:13 PM.
Dec 16, 2005, 07:11 PM
#94
Sorry Virus but i think I missed most of your point Im just saying there is not one advantage to the MAF for most of our needs (If not all of us). And personally I am quite confident the stock MAF is a restriction at the 500hp level and I am sure it is missing counts at that level (In which case it is not as accurate anyways). My whole thing with this debate was also aimed at the stock MAF considering anything else would require a decent amount of money and tuning and would not be worth any of it in the end.
And if you are curious to know how well the stock MAF holds up I will post you some pics of what my MAF is. Give you a hint... my turbo almost ate it
Im just saying there is not one advantage to the MAF for most of our needs (If not all of us). And personally I am quite confident the stock MAF is a restriction at the 500hp level and I am sure it is missing counts at that level (In which case it is not as accurate anyways). My whole thing with this debate was also aimed at the stock MAF considering anything else would require a decent amount of money and tuning and would not be worth any of it in the end. And if you are curious to know how well the stock MAF holds up I will post you some pics of what my MAF is. Give you a hint... my turbo almost ate it
Dec 16, 2005, 07:13 PM
#96
Originally Posted by EVOla_VIRUS
Were are not saying it CANT do it...cause the car does start right? lol but its adaptable like the Terminator is...
Edit: adaptable you say...think of it this way.....altitude. As you go up in the air you loose air pressure. Take a car to 4000ft and the computer might think your WOT or something yet your TPS is not even open....speed density says "WTF??" while MAF has the adaptability to over come.
Edit: adaptable you say...think of it this way.....altitude. As you go up in the air you loose air pressure. Take a car to 4000ft and the computer might think your WOT or something yet your TPS is not even open....speed density says "WTF??" while MAF has the adaptability to over come.
Dec 16, 2005, 07:16 PM
#97
Originally Posted by TrinaBabe
Dont know if I should tell you this or not but.... the Kavlico sensor measures PSIA.. altitude is already compensated.
Dec 16, 2005, 07:16 PM
#98
I have been trying to understand your reasoning, but what you are trying to convey as facts are examples of technology.
I feel Ted has given many reasons why the MAF system is superior to a Speed density.
For race car applications speed density is technology that is readily available and MAF system/technology is fairly new and state of the art.
To the question of why race cars do not use it, the answer has already been explained...race cars run in a very narrow operation range and the tuner can make corrections on the fly for any change in conditions, these being ambient or mechanical.
For example the new 1001 hp EB Veyron uses Bosch ME MAF system. VW/Audi have MAF based ECU technology that is very intricate that uses map, iat, and wb 02 for closed loop boost control and open loop AFR adaptation . If only source code was readily available to tune these systems like ecutek or techtom, these ECUs would rival any high $ standalone system available, unfortunately this is not the case.
In your case and based on your application, speed density may be the best solution for you. But that does not mean that speed density is superior to MAF system.
I feel Ted has given many reasons why the MAF system is superior to a Speed density.
For race car applications speed density is technology that is readily available and MAF system/technology is fairly new and state of the art.
To the question of why race cars do not use it, the answer has already been explained...race cars run in a very narrow operation range and the tuner can make corrections on the fly for any change in conditions, these being ambient or mechanical.
For example the new 1001 hp EB Veyron uses Bosch ME MAF system. VW/Audi have MAF based ECU technology that is very intricate that uses map, iat, and wb 02 for closed loop boost control and open loop AFR adaptation . If only source code was readily available to tune these systems like ecutek or techtom, these ECUs would rival any high $ standalone system available, unfortunately this is not the case.
In your case and based on your application, speed density may be the best solution for you. But that does not mean that speed density is superior to MAF system.
Originally Posted by TrinaBabe
I think it is incredibly great how I can explain very easily certain points that make a speed density car better and you cant find one real reason for a MAF.
Dec 16, 2005, 07:19 PM
#99
[QUOTE=Jorge T]I have been trying to understand your reasoning, but what you are trying to convey as facts are examples of technology.
I feel Ted has given many reasons why the MAF system is superior to a Speed density.
For race car applications speed density is technology that is readily available and MAF system/technology is fairly new and state of the art.[QUOTE]
MAF has been around for about 20 yrs...Heck even Rustangs had them with there old 5ooohhhs lol. They are almost concurent running technology
I feel Ted has given many reasons why the MAF system is superior to a Speed density.
For race car applications speed density is technology that is readily available and MAF system/technology is fairly new and state of the art.[QUOTE]
MAF has been around for about 20 yrs...Heck even Rustangs had them with there old 5ooohhhs lol. They are almost concurent running technology
Dec 16, 2005, 07:23 PM
#100
Well I will agree with some of your post and disagree with part as well.... As for these cars only driving in a narrow range that is incorrect... Look at an F1.. they are not full throttle at high RPM the whole race... they dip to extermely low RPMs, low throttle all the way to extremely high throttle and high RPM. They do not use a MAF.
I am not saying that speed density is a technological better way to measure airflow.. I AM stating that in our cases it is superior. There is nothing that makes a MAF better for our cars. Considering this is an Evo forum and we are talking specifically about our cars, the speed density has many advantages over the stock MAF. That is my only point... I never meant this all to become an engineering **** battle, yes I agree the MAF is more advanced and superior in measuring airflow. In our cases, speed density is a better approach. Thats my only point.
And why is it no one can summarize the great points of the MAF then? I didnt think I was too stupid to see them but apparently I am (I will never hide if I honestly missed something). I am not dead set on either system being superior but in everything I can see, the speed density approach is superior in our cases, with our cars for our uses.
I am not saying that speed density is a technological better way to measure airflow.. I AM stating that in our cases it is superior. There is nothing that makes a MAF better for our cars. Considering this is an Evo forum and we are talking specifically about our cars, the speed density has many advantages over the stock MAF. That is my only point... I never meant this all to become an engineering **** battle, yes I agree the MAF is more advanced and superior in measuring airflow. In our cases, speed density is a better approach. Thats my only point.
And why is it no one can summarize the great points of the MAF then? I didnt think I was too stupid to see them but apparently I am (I will never hide if I honestly missed something). I am not dead set on either system being superior but in everything I can see, the speed density approach is superior in our cases, with our cars for our uses.
Dec 16, 2005, 07:32 PM
#102
[QUOTE=EVOla_VIRUS][QUOTE=Jorge T]I have been trying to understand your reasoning, but what you are trying to convey as facts are examples of technology.
I feel Ted has given many reasons why the MAF system is superior to a Speed density.
For race car applications speed density is technology that is readily available and MAF system/technology is fairly new and state of the art.
MAF has been around for about 20 yrs...Heck even Rustangs had them with there old 5ooohhhs lol. They are almost concurent running technology
I though a 1985' rustang GT had a 4barrel carb, don't scare me lol time sure flies .
I feel Ted has given many reasons why the MAF system is superior to a Speed density.
For race car applications speed density is technology that is readily available and MAF system/technology is fairly new and state of the art.
MAF has been around for about 20 yrs...Heck even Rustangs had them with there old 5ooohhhs lol. They are almost concurent running technology
Dec 16, 2005, 07:33 PM
#103
Originally Posted by Jorge T
I though a 1985' rustang GT had a 4barrel carb, don't scare me lol time sure flies .
Dec 16, 2005, 07:41 PM
#104
Originally Posted by TrinaBabe
As for these cars only driving in a narrow range that is incorrect... Look at an F1.. they are not full throttle at high RPM the whole race... they dip to extermely low RPMs, low throttle all the way to extremely high throttle and high RPM. They do not use a MAF.
Originally Posted by TrinaBabe
And why is it no one can summarize the great points of the MAF then? I didnt think I was too stupid to see them but apparently I am (I will never hide if I honestly missed something).
Dec 16, 2005, 07:47 PM
#105
Geez...think of MAPed cars as auto's with engine simulations programmed in the PROM and MAF equiped cars as real time adapting cause of its ability to measure air flow....which MAP does NOT DO for the umpteenth time; it measures vaccum hence engine load. Sorry if that sounds way too simplified lol