Using Maf
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From: Conway, AR
Yeah man stay with the MAF, if you are staying N/A it is much easier to tune. Get that VE dialed in as close as you can then go back and do the MAF. It's much easier to tune that way. Have you bought a wideband yet or are you still tuning with trims? As long as you tune the VE right the MAF will be super easy to dial in and will yield the same power gains after tuning.
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From: Sunny London, UK
Originally Posted by tblu92
--also when it's 60* outside and when it's 100* outside you wil need to tune it again---It doesn't cpmpinsate for weather or altitude--
Can you tell me what the IAT sensor does?
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From: Conway, AR
He was talking about VE, but even with speed density, if you have a good enough tune you wont have to tune it for weather changes. In trucks, the IAT is in the MAF and it measure the intake temps for SD fueling calculations.
Also, MAF is a blend with VE off idle all the way to 4000, not just 3k up. Any transition state till 4k rpms is blended.
Also, MAF is a blend with VE off idle all the way to 4000, not just 3k up. Any transition state till 4k rpms is blended.
Originally Posted by chrisj6
Yeah man stay with the MAF, if you are staying N/A it is much easier to tune. Get that VE dialed in as close as you can then go back and do the MAF. It's much easier to tune that way. Have you bought a wideband yet or are you still tuning with trims? As long as you tune the VE right the MAF will be super easy to dial in and will yield the same power gains after tuning.
Originally Posted by yobabiesdaddy2001
Ok I am going to stay with the maf Chris. Yes I am dialing in the Ve the narrow band way. Until my Wideband gets here after Christmas. You mentioned dialing in the MaF after I finsh with the VE table, what do you mean or where can I find out how to do it?
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tblue92, since you know so much, would you please explain to us (prefferably in mathematical form to avoid ambiguities) the idea behind Speed Density? How would one go about calculating airflow?
The MAP sensor measures pressure. Hmm, that takes care of altitude or density. The IAT sensor measures temperature. Well, that should just be self-explanatory. So yes, an SD tune does account for altitude, pressure, and temperature changes.
displacement and VE determines effective volume
MAP, Temp and gas constant for air determine density
airmass is effective volume times density
airflow is airmass times RPM
so MAP and Temp affect density, accounting for weather/altitude/pressure changes.
VE is displacement and conditions independent, so you dont have to retune it for weather.
happy holidays
MAP, Temp and gas constant for air determine density
airmass is effective volume times density
airflow is airmass times RPM
so MAP and Temp affect density, accounting for weather/altitude/pressure changes.
VE is displacement and conditions independent, so you dont have to retune it for weather.
happy holidays
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From: Sunny London, UK
Chill dude, its christmas.
Im not sure how I miss quoted you considering I used in the inline quote feature to quote your exact words.
g/cyl = VE*MAP/charge temperature
Thats the calc the pcm uses to figure out air and from that the commanded fuel to use.
As you can see Temp and Pressure are in there. So open your mind and realize every day is a learning day.
Seeing as you have read my blog page, Im sure you have read that Im learning all the time too. Hell reading Marcin's pages (RedHardSupra) you will see he is too. Thats why we use this forum.
The fueling changes you speak of for temperature variations are determined by the "Charge Temperature Blending" Table in efilive, B4901 This table has nothing to do with MAF and SD, but is solely related to ECT and IAT, as seen above its part of the g/cyl formula.
Im not sure how I miss quoted you considering I used in the inline quote feature to quote your exact words.
g/cyl = VE*MAP/charge temperature
Thats the calc the pcm uses to figure out air and from that the commanded fuel to use.
As you can see Temp and Pressure are in there. So open your mind and realize every day is a learning day.
Seeing as you have read my blog page, Im sure you have read that Im learning all the time too. Hell reading Marcin's pages (RedHardSupra) you will see he is too. Thats why we use this forum.
The fueling changes you speak of for temperature variations are determined by the "Charge Temperature Blending" Table in efilive, B4901 This table has nothing to do with MAF and SD, but is solely related to ECT and IAT, as seen above its part of the g/cyl formula.
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From: Conway, AR
Originally Posted by tblu92
gametech---I know the MAP measues pressure and the IAT measures air temps---BUT what you don't understand is that the information they gather uses the MAF to adjust fueling---they don't have the ability to make fuel changes on their own !!!!!---they read information only---sent it to the MAF and the MAF corrects the fueling-----IF you take the MAF out of the equation---HOW will the information they gather adjust anything ??????? they can't---
My point exactly why taking the MAF out of the equation leaves you 100% with the fueling you programmed into the VE table. And for the street--that sucks.
My point exactly why taking the MAF out of the equation leaves you 100% with the fueling you programmed into the VE table. And for the street--that sucks.
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From: Sunny London, UK
Originally Posted by tblu92
gametech---I know the MAP measues pressure and the IAT measures air temps---BUT what you don't understand is that the information they gather uses the MAF to adjust fueling---they don't have the ability to make fuel changes on their own !!!!!---they read information only---sent it to the MAF and the MAF corrects the fueling-----IF you take the MAF out of the equation---HOW will the information they gather adjust anything ??????? they can't---
My point exactly why taking the MAF out of the equation leaves you 100% with the fueling you programmed into the VE table. And for the street--that sucks.
My point exactly why taking the MAF out of the equation leaves you 100% with the fueling you programmed into the VE table. And for the street--that sucks.
Also a FYI, gametech is a developer from HPTuners so I think he has a fair idea what he is talking about.
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From: Conway, AR
Originally Posted by ringram
Dude I suggest you go and re-read all your notes. I think you missed something basic.
Also a FYI, gametech is a developer from HPTuners so I think he has a fair idea what he is talking about.
Also a FYI, gametech is a developer from HPTuners so I think he has a fair idea what he is talking about.
