Please Expalin SPEED DENSITY TUNING
Please Expalin SPEED DENSITY TUNING well i dont kno if the section im posting is right, but a MAF is somewhat a "bolt on" so im ask, whats the speed desity all about? any major benefits? reason im asking is due to having a 92mm fast and not wanting to pay for a100mm maf or 85 and not knowing that size and so on so im thinkng of sd tuning
Not to be off-topic but it'd be cheaper to buy the MAF than it will be for an SD tune from most places. I know the SD deletes the MAF but I'm sorry I can't explain the rest becaust I don't know myself! lol I'm interested too.
TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
MAF = PCM calculates the cylinder fill airmass using MAF and RPM.
SD = PCM calculates the cylinder fill airmass using VE, MAP, IAT, and RPM.
VE is the table telling the PCM how much mass/volume the cylinder fill is at any RPM vs MAP.
When running with MAF, the PCM uses both MAF and VE at various times.
When running SD, the PCM obviously ignores MAF.
With your non-stock intake manifold, either way (MAF or SD) requires correcting both MAF and VE tables (the intake manifold change will alter airflow thru the MAF sensor, the MAF sensor was previously calibrated for it's immediate surroundings).
Either way you have to pay for a tune; SD eliminates the [cost of] the MAF sensor.
Eliminating the MAF sensor protects the PCM's airmass calculation from incorrect intake plumbing (bends too close to MAF) and from reversion effects.
Running SD is a fail-over mode and so it has side-effects, for example: spark timing adapt now defaults to low octane spark table (you lose the sliding between the HO and LO tables), and transmission pressure adapt defaults to fault mode (max pressure, no shift feel adapts), and other things not fully known.
SD = PCM calculates the cylinder fill airmass using VE, MAP, IAT, and RPM.
VE is the table telling the PCM how much mass/volume the cylinder fill is at any RPM vs MAP.
When running with MAF, the PCM uses both MAF and VE at various times.
When running SD, the PCM obviously ignores MAF.
With your non-stock intake manifold, either way (MAF or SD) requires correcting both MAF and VE tables (the intake manifold change will alter airflow thru the MAF sensor, the MAF sensor was previously calibrated for it's immediate surroundings).
Either way you have to pay for a tune; SD eliminates the [cost of] the MAF sensor.
Eliminating the MAF sensor protects the PCM's airmass calculation from incorrect intake plumbing (bends too close to MAF) and from reversion effects.
Running SD is a fail-over mode and so it has side-effects, for example: spark timing adapt now defaults to low octane spark table (you lose the sliding between the HO and LO tables), and transmission pressure adapt defaults to fault mode (max pressure, no shift feel adapts), and other things not fully known.
Last edited by joecar; Nov 2, 2010 at 03:17 PM. Reason: typos...
MAF = PCM calculates the cylinder fill airmass using MAF and RPM.
SD = PCM calculates the cylinder fill airmass using MAP, IAT, VE and RPM.
VE is the table telling the PCM how much mass/volume the cylinder fill is at any RPM vs MAP.
When running with MAF, the PCM uses both MAF and VE at various times.
When running SD, the PCM obviously ignores MAF.
With your non-stock intake manifold, either way (MAF or SD) requires correcting both MAF and VE tables (the intake manifold change will alter airflow thru the MAF sensor, the MAF sensor was previously calibrated for it's immediate surroundings).
Either way you have to pay for a tune; SD eliminates the [cost of] the MAF sensor.
Eliminating the MAF sensor protects the PCM's airmass calculation from incorrect intake plumbing (bends too close to MAF) and from reversion effects.
Running SD is a fail-over mode and so it has side-effects, for example: spark timing adapt now defaults to low octane spark table (you lose the sliding between the HO and LO tables), and transmission pressure adapt defaults to fault mode (max pressure, no shift feel adapts), and other things not fully known.
SD = PCM calculates the cylinder fill airmass using MAP, IAT, VE and RPM.
VE is the table telling the PCM how much mass/volume the cylinder fill is at any RPM vs MAP.
When running with MAF, the PCM uses both MAF and VE at various times.
When running SD, the PCM obviously ignores MAF.
With your non-stock intake manifold, either way (MAF or SD) requires correcting both MAF and VE tables (the intake manifold change will alter airflow thru the MAF sensor, the MAF sensor was previously calibrated for it's immediate surroundings).
Either way you have to pay for a tune; SD eliminates the [cost of] the MAF sensor.
Eliminating the MAF sensor protects the PCM's airmass calculation from incorrect intake plumbing (bends too close to MAF) and from reversion effects.
Running SD is a fail-over mode and so it has side-effects, for example: spark timing adapt now defaults to low octane spark table (you lose the sliding between the HO and LO tables), and transmission pressure adapt defaults to fault mode (max pressure, no shift feel adapts), and other things not fully known.
Teching In
Joined: Sep 2010
Posts: 46
Likes: 0
From: Ft.Lauderdale, FL
MAF = PCM calculates the cylinder fill airmass using MAF and RPM.
SD = PCM calculates the cylinder fill airmass using MAP, IAT, VE and RPM.
VE is the table telling the PCM how much mass/volume the cylinder fill is at any RPM vs MAP.
When running with MAF, the PCM uses both MAF and VE at various times.
When running SD, the PCM obviously ignores MAF.
With your non-stock intake manifold, either way (MAF or SD) requires correcting both MAF and VE tables (the intake manifold change will alter airflow thru the MAF sensor, the MAF sensor was previously calibrated for it's immediate surroundings).
Either way you have to pay for a tune; SD eliminates the [cost of] the MAF sensor.
Eliminating the MAF sensor protects the PCM's airmass calculation from incorrect intake plumbing (bends too close to MAF) and from reversion effects.
Running SD is a fail-over mode and so it has side-effects, for example: spark timing adapt now defaults to low octane spark table (you lose the sliding between the HO and LO tables), and transmission pressure adapt defaults to fault mode (max pressure, no shift feel adapts), and other things not fully known.
SD = PCM calculates the cylinder fill airmass using MAP, IAT, VE and RPM.
VE is the table telling the PCM how much mass/volume the cylinder fill is at any RPM vs MAP.
When running with MAF, the PCM uses both MAF and VE at various times.
When running SD, the PCM obviously ignores MAF.
With your non-stock intake manifold, either way (MAF or SD) requires correcting both MAF and VE tables (the intake manifold change will alter airflow thru the MAF sensor, the MAF sensor was previously calibrated for it's immediate surroundings).
Either way you have to pay for a tune; SD eliminates the [cost of] the MAF sensor.
Eliminating the MAF sensor protects the PCM's airmass calculation from incorrect intake plumbing (bends too close to MAF) and from reversion effects.
Running SD is a fail-over mode and so it has side-effects, for example: spark timing adapt now defaults to low octane spark table (you lose the sliding between the HO and LO tables), and transmission pressure adapt defaults to fault mode (max pressure, no shift feel adapts), and other things not fully known.
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also has ANYONE RAN THE TSP 100mm MAF? I am interested in it but has that had tuning issues? i havent seen much of anything about it
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Staging Lane
Joined: Jan 2010
Posts: 85
Likes: 0
From: des moines, iowa
Im not using the factory box, I have a volant CAI and SLP smoothe bellows, and Im usin hose clamps to hold it all together. I dont ahve any pics on my computer ironically enough but I can get some on here and send you one
lol nope i dont deal with redline, if i could direct you to some 1 whos 20mins from redline in clifton park, Anthony Coppola, www.coppolamotorsports.com very good knowladgeable guy
Installing a larger MAF isn't really a bolt on, your tune should be looked at.
one thing I'd like to add is that with a MAF tune it still takes data from the map sensor and enters it into the calculation.
My advice do your research find a tuner your comfortable with and work with him to come up with what is best for your car.
one thing I'd like to add is that with a MAF tune it still takes data from the map sensor and enters it into the calculation.
My advice do your research find a tuner your comfortable with and work with him to come up with what is best for your car.
Installing a larger MAF isn't really a bolt on, your tune should be looked at.
one thing I'd like to add is that with a MAF tune it still takes data from the map sensor and enters it into the calculation.
My advice do your research find a tuner your comfortable with and work with him to come up with what is best for your car.
one thing I'd like to add is that with a MAF tune it still takes data from the map sensor and enters it into the calculation.
My advice do your research find a tuner your comfortable with and work with him to come up with what is best for your car.
Registered User
Joined: Jul 2010
Posts: 24
Likes: 0
From: Australia
Just about every car in Aus that gets tuned is tuned mafless or what you call speed density theirs no issues provided it is tuned properly without a maf in place at all.
All the things above mentioned spark tables, lines pressures etc can all be changed so i dont see the issue running mafless.
I assume the reason all you guys stay with the MAF is for emission reasons, but having said that the main reason its removed over here is because the standard MAF is a restriction if you had a 100mm MAF then it would make no difference also its not going to make any power difference unless your removing the stock MAF or a restrictive MAF, your also said to gain better throttle response.
So either get a big maf that flows alot of cfm's or just take it over and run mafless.
All the things above mentioned spark tables, lines pressures etc can all be changed so i dont see the issue running mafless.
I assume the reason all you guys stay with the MAF is for emission reasons, but having said that the main reason its removed over here is because the standard MAF is a restriction if you had a 100mm MAF then it would make no difference also its not going to make any power difference unless your removing the stock MAF or a restrictive MAF, your also said to gain better throttle response.
So either get a big maf that flows alot of cfm's or just take it over and run mafless.
