Higher HP cars with MAF still come in
04-08-2012, 08:53 PM
#1
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Higher HP cars with MAF still come in http://texas-speed.com/p-1196-gm-mas...-2006-z06.aspx
I have a 585 rwhp 99 SS with D1 procharger on 10#. The GM 85mm MAF I have on there now is pegged around 4300 rpm. I want to run a MAF on my car because I don't really trust the car in speed density. Could I run this on my car? I don't think C6 zo6's have problems pegging their MAF around 600 HP do they? Any idea how to hook this up to a ls1 camaro harness?
I have a 585 rwhp 99 SS with D1 procharger on 10#. The GM 85mm MAF I have on there now is pegged around 4300 rpm. I want to run a MAF on my car because I don't really trust the car in speed density. Could I run this on my car? I don't think C6 zo6's have problems pegging their MAF around 600 HP do they? Any idea how to hook this up to a ls1 camaro harness?
04-09-2012, 08:57 AM
#4
http://texas-speed.com/p-1196-gm-mas...-2006-z06.aspx
I have a 585 rwhp 99 SS with D1 procharger on 10#. The GM 85mm MAF I have on there now is pegged around 4300 rpm. I want to run a MAF on my car because I don't really trust the car in speed density. Could I run this on my car? I don't think C6 zo6's have problems pegging their MAF around 600 HP do they? Any idea how to hook this up to a ls1 camaro harness?
I have a 585 rwhp 99 SS with D1 procharger on 10#. The GM 85mm MAF I have on there now is pegged around 4300 rpm. I want to run a MAF on my car because I don't really trust the car in speed density. Could I run this on my car? I don't think C6 zo6's have problems pegging their MAF around 600 HP do they? Any idea how to hook this up to a ls1 camaro harness?
04-09-2012, 01:42 PM
#5
http://texas-speed.com/p-660-texas-s...ow-sensor.aspx
I am running this 100mm MAF, but my car is normally aspirated. I am making around 520 rwhp, and I havent had a problem with it. If I was going forced induction I would definately run a speed density tune though.
I am running this 100mm MAF, but my car is normally aspirated. I am making around 520 rwhp, and I havent had a problem with it. If I was going forced induction I would definately run a speed density tune though.
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04-20-2012, 03:47 PM
#10
If you want to run a MAF at higher HP in a car with a Gen 3 PCM, you need to "scale" the tune...essentially you tell the PCM the injectors are flowing half as much fuel as they really are, and then you calibrate the MAF to read half the air...then on any and all airflow referenced tables...you have to do the same thing so that you command the correct spark and fuel at any given time. You have to do this because the LS1 PCM is going to limit it's airflow measurement to 512 grams/second...regardless of frequency...you can get around the frequency issue by running the MAF in a larger diameter tube, but you can't get around the 512 grams/second problem unless you scale the tune.
Check out something like the HPTuners forum, and search for scaling.
Check out something like the HPTuners forum, and search for scaling.
04-20-2012, 08:08 PM
#11
That is only if you max the maf out as far as fueling though. With the LS7 maf conversion, there is no need to scale the tune, it will automatically read in the lower hz range and on a 600 rwhp NA car it is not maxing it out, so I would say you are ok with going to that.
04-21-2012, 08:08 AM
#13
How much power did you make? Some people always scale by 50%, but if you were only pegging it for a tiny bit, you can scale it by a higher %, like 80 or something, and maintain more resolution in the tables in the PCM when tuning the car.
04-21-2012, 02:48 PM
#14
Depending on the drivetrain setup, RWHP and g/sec on a well calibrated MAF are sometimes not as far away from each other as you'd think...600 rwhp NA or boosted is very possibly, if not very likely, exceeding 512 grams/second of actual airflow...if you didn't tune it yourself, and you can't look inside the PCM, don't be so sure that your 600 rwhp NA doesn't have the end of the PE table hacked where the PCM can't register any more airflow in order to try to keep AFR where you want it. It might not be, but it could be.
The larger diameter tube is the same as what you're saying by LS7 MAF conversion...the newer style card MAF sensors that slide into a tube...any diameter tube you want to put the MAF in...the larger it is, the lower the frequency will be for any given amount of airflow in the tube...up to the 12,000 hz that the Gen 3 PCM's can measure...and if you're registering 512 grams/second significantly below 12,000 hz, you're running it in too large a tube for your application and sacrificing resolution of the sensor. If it's in a Gen 4 PCM car, depending on the application and in some cases if you apply the proper OS enhancement, it will work up to 15,000 hz, and in some cases, like the 2010 Camaro SS, 4000 grams/second.
How much power did you make? Some people always scale by 50%, but if you were only pegging it for a tiny bit, you can scale it by a higher %, like 80 or something, and maintain more resolution in the tables in the PCM when tuning the car.
The larger diameter tube is the same as what you're saying by LS7 MAF conversion...the newer style card MAF sensors that slide into a tube...any diameter tube you want to put the MAF in...the larger it is, the lower the frequency will be for any given amount of airflow in the tube...up to the 12,000 hz that the Gen 3 PCM's can measure...and if you're registering 512 grams/second significantly below 12,000 hz, you're running it in too large a tube for your application and sacrificing resolution of the sensor. If it's in a Gen 4 PCM car, depending on the application and in some cases if you apply the proper OS enhancement, it will work up to 15,000 hz, and in some cases, like the 2010 Camaro SS, 4000 grams/second.
How much power did you make? Some people always scale by 50%, but if you were only pegging it for a tiny bit, you can scale it by a higher %, like 80 or something, and maintain more resolution in the tables in the PCM when tuning the car.
04-22-2012, 07:54 AM
#16
I don't think anyone said a specific way of tuning is wrong...we're pointing out that what you posted as "fact" about how an LS7 MAF sensor works...that's wrong. If the MAF is calibrated accurately for the actual air flow number into your engine, your gen 3 PCM is limited to 512 grams/second of airflow, it doesn't matter what sensor it is, or what frequency it's reading or how large the tube is that it's installed in. If it's reading any number other than the actual correct airflow, then the tune is scaled, either scaled properly as I have described, or some hacked up disaster...but nonetheless scaled, and as you've said scaling is unnecessary, so you're contradicting your own argument. If you think when I say your car fueling on raped PE only up top is wrong is wrong...then you just don't understand why it's unsafe, and I hope for your sake that your engine doesn't blow up.
04-22-2012, 03:56 PM
#17
I posted a fact because I have tuned with them. Is that fact enough?
When you use a diff maf sensor, the tune is not scaled itself. You are looking at it from the wrong angle. Just because the sensor starts to read in the lower HZ does not mean it is scaled as there is no other table you have to touch in reference to it to make sure it functions right. Scaling the tune and running a diff maf are 2 different things.
And I do not rape the PE table either. But, if a tuner targets a lower AFR in the PE, then you would not have to add as much in the maf table....and you would not have to worry about hitting the limit of fuel adding in the maf table.
Assuming that I was talking about me when I said that was not correct.
When you use a diff maf sensor, the tune is not scaled itself. You are looking at it from the wrong angle. Just because the sensor starts to read in the lower HZ does not mean it is scaled as there is no other table you have to touch in reference to it to make sure it functions right. Scaling the tune and running a diff maf are 2 different things.
And I do not rape the PE table either. But, if a tuner targets a lower AFR in the PE, then you would not have to add as much in the maf table....and you would not have to worry about hitting the limit of fuel adding in the maf table.
Assuming that I was talking about me when I said that was not correct.
04-22-2012, 09:39 PM
#18
I posted a fact because I have tuned with them. Is that fact enough?
When you use a diff maf sensor, the tune is not scaled itself. You are looking at it from the wrong angle. Just because the sensor starts to read in the lower HZ does not mean it is scaled as there is no other table you have to touch in reference to it to make sure it functions right. Scaling the tune and running a diff maf are 2 different things.
And I do not rape the PE table either. But, if a tuner targets a lower AFR in the PE, then you would not have to add as much in the maf table....and you would not have to worry about hitting the limit of fuel adding in the maf table.
Assuming that I was talking about me when I said that was not correct.
When you use a diff maf sensor, the tune is not scaled itself. You are looking at it from the wrong angle. Just because the sensor starts to read in the lower HZ does not mean it is scaled as there is no other table you have to touch in reference to it to make sure it functions right. Scaling the tune and running a diff maf are 2 different things.
And I do not rape the PE table either. But, if a tuner targets a lower AFR in the PE, then you would not have to add as much in the maf table....and you would not have to worry about hitting the limit of fuel adding in the maf table.
Assuming that I was talking about me when I said that was not correct.
If you run a different MAF sensor in a larger tube and read a lower frequency, you need to re-calibrate the MAF table, if you don't you're going to have ridiculous part throttle fuel trims, and you're going to have a PE table where you're targeting some AFR that is completely different than the actual AFR you want the wideband to see in the exhaust...and if a tuner is doing that to the PE table (commanding an AFR that is not actually the one they want to achieve), then yes, they are raping the PE table, and they have no business charging people money for their hackjob tuning.
Spark advance is also referenced to airflow, and fuel trims will not correct that, which results in incorrect/undesired spark advance when the MAF isn't calibrated properly. If you scale the tune properly you ARE misleading the PCM about how much airflow it's seeing, but you're misleading it by an exact known amount so that you can get everything else to behave correctly, you don't need to lie to the PE table, your fuel trims will function normally, and your spark advance will be the actual desired advance.
04-23-2012, 07:37 PM
#19
No, it's not fact enough to know that you've tuned them yourself...that just means you've either never actually calibrated the MAF sensor based on target AFR, and actual AFR measured with a wideband given accurate fuel injector calibration data, OR you've never tuned a car making enough power to exceed 512 grams per second of airflow, so you don't understand the limitation of the PCM that I'm explaining...grams per second is grams per second, at ANY hz, it does not matter. Gen 3 PCM's are limited to 512 grams/second in the MAF calibration.
If you run a different MAF sensor in a larger tube and read a lower frequency, you need to re-calibrate the MAF table, if you don't you're going to have ridiculous part throttle fuel trims, and you're going to have a PE table where you're targeting some AFR that is completely different than the actual AFR you want the wideband to see in the exhaust...and if a tuner is doing that to the PE table (commanding an AFR that is not actually the one they want to achieve), then yes, they are raping the PE table, and they have no business charging people money for their hackjob tuning.
Spark advance is also referenced to airflow, and fuel trims will not correct that, which results in incorrect/undesired spark advance when the MAF isn't calibrated properly. If you scale the tune properly you ARE misleading the PCM about how much airflow it's seeing, but you're misleading it by an exact known amount so that you can get everything else to behave correctly, you don't need to lie to the PE table, your fuel trims will function normally, and your spark advance will be the actual desired advance.
If you run a different MAF sensor in a larger tube and read a lower frequency, you need to re-calibrate the MAF table, if you don't you're going to have ridiculous part throttle fuel trims, and you're going to have a PE table where you're targeting some AFR that is completely different than the actual AFR you want the wideband to see in the exhaust...and if a tuner is doing that to the PE table (commanding an AFR that is not actually the one they want to achieve), then yes, they are raping the PE table, and they have no business charging people money for their hackjob tuning.
Spark advance is also referenced to airflow, and fuel trims will not correct that, which results in incorrect/undesired spark advance when the MAF isn't calibrated properly. If you scale the tune properly you ARE misleading the PCM about how much airflow it's seeing, but you're misleading it by an exact known amount so that you can get everything else to behave correctly, you don't need to lie to the PE table, your fuel trims will function normally, and your spark advance will be the actual desired advance.
04-24-2012, 12:36 AM
#20
Oh yah, he so totally put me in my place. I just put ls7 mafs in cars, do not tune them, and let them run. I also do not adjust the IAT tables, because they have to be revamped too. Wow, gee, thanks for that!