MAF Vs. Speed density
09-26-2011, 09:12 PM
#1
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MAF Vs. Speed density I have a 2000 6 speed SS with stage 2 MTI heads, cam, and full exhaust. I have a speed Inc mail order tune. I need to send the computer back in to correct for a gear change and I am wondering if I should go to a speed density tune... WHat are the pros and cons to both? Obviously the mpg might not be as good but will it really be that much worse? Also roughly how much HP will I gain? Any info would be greatly appreciated! THanks!
09-28-2011, 08:25 AM
#2
Keep the MAF... what most don't realize is unless the tuner disables SD by setting dynamic airflow calculations below a sane point the factory setup runs in a hybrid of SD/MAF. Properly calibrated the SD/MAF will run superior to SD only. Whoever say's SD will make more power doesn't know how to calibrate a MAF properly. The ONLY way SD will make more power is if the MAF itself is a restriction. With the big housing card style MAF available today I don't see them being a restriction.
09-28-2011, 03:20 PM
#3
I run SD on my Z06. There is no power gain or mileage differences if both are tuned properly in the first place. The MAF is not a restriction.
The only reason to ditch the MAF is if your cam is so huge that you are getting reversion into your MAF and it's messing up your idle and low speed driveability.
I run MAF only, in fact, on my 2011 Silverado.....just the opposite.
The only reason to ditch the MAF is if your cam is so huge that you are getting reversion into your MAF and it's messing up your idle and low speed driveability.
I run MAF only, in fact, on my 2011 Silverado.....just the opposite.
09-28-2011, 04:19 PM
#4
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i bought my car previously tuned and it runs way 2 rich... 02 z06 G5x3.. i cant get ahold of the tuner to see how he tuned it.. the previous owner said the tuner that tuned it couldnt keep it at idle without it running rich... can i hook it up to HP and will it tell me if it was MAF or SD tuned? LG Motorsports told me that it deff needs a MAF tune if it is running that rich. Whats funny is my gas mileage is awsome but at idle in closed loop is when i notice the richness... So MAF or SD for my cammed car?
09-29-2011, 07:16 AM
#5
i bought my car previously tuned and it runs way 2 rich... 02 z06 G5x3.. i cant get ahold of the tuner to see how he tuned it.. the previous owner said the tuner that tuned it couldnt keep it at idle without it running rich... can i hook it up to HP and will it tell me if it was MAF or SD tuned? LG Motorsports told me that it deff needs a MAF tune if it is running that rich. Whats funny is my gas mileage is awsome but at idle in closed loop is when i notice the richness... So MAF or SD for my cammed car?
Force open loop idle through PE table
or
run open loop full time (what I do)
or
spend a LOT of time trying to tune your closed loop tables to get the O2 sensors to read right and stop overfueling idle (good luck)
09-29-2011, 09:07 AM
#6
maf will work fine on your car, but the idle is off because the O2 sensors in the long tubes are confused. you have three options.
Force open loop idle through PE table
or
run open loop full time (what I do)
or
spend a LOT of time trying to tune your closed loop tables to get the O2 sensors to read right and stop overfueling idle (good luck)
Force open loop idle through PE table
or
run open loop full time (what I do)
or
spend a LOT of time trying to tune your closed loop tables to get the O2 sensors to read right and stop overfueling idle (good luck)
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09-30-2011, 07:40 AM
#10
No, also don't mix open/closed loop with MAF/SD. Two TOTALLY different things. The only control the Gen3 pcm has on MAF/SD is when the mix of MAF/SD disables and then run's purely on MAF. And that is rpm based. Most all factory LS1/6 tune's I've seen is set to go purely MAF based above 4000rpm.
09-30-2011, 08:28 AM
#12
No, also don't mix open/closed loop with MAF/SD. Two TOTALLY different things. The only control the Gen3 pcm has on MAF/SD is when the mix of MAF/SD disables and then run's purely on MAF. And that is rpm based. Most all factory LS1/6 tune's I've seen is set to go purely MAF based above 4000rpm.
09-30-2011, 10:40 AM
#13
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The MAF is a good instrument with only a few ways to
go bad, which you can easily avoid. It makes for a
much steadier low end fueling in my experience (MAP
surge, gone when enabled) and is pretty accurate
right out of the box unless you have no screen and
a really bent inlet tract.
SD puts you at the mercy of environment (IAT) and
needs redone for minor mods because pushing reality
updates into the VE table is all on you.
The only good reason for ditching the MAF is when
your setup grows a third nut and you pull more air
than it can meter. Until then its consistency is your
daily driver friend.
go bad, which you can easily avoid. It makes for a
much steadier low end fueling in my experience (MAP
surge, gone when enabled) and is pretty accurate
right out of the box unless you have no screen and
a really bent inlet tract.
SD puts you at the mercy of environment (IAT) and
needs redone for minor mods because pushing reality
updates into the VE table is all on you.
The only good reason for ditching the MAF is when
your setup grows a third nut and you pull more air
than it can meter. Until then its consistency is your
daily driver friend.
09-30-2011, 12:25 PM
#15
Yes you can set the MAF to fail however it will not re-enable (on the OS's I've messed with) once failed until the key is cycled. So setting the MAF fail frequency to ~5500hz would fault the MAF out if it read above that frequency however when you got back down below that point it would not re-enable.
There is nothing wrong with SD, I ran my stroker setup SD because I was maxing out the flow limits of the PCM NA and didn't want to scale the injectors to make it work, so I ditched it to run SD. However on setups that are more mild it's no benefit really to delete it. My Formula which is a cam only car has an OE 85mm truck MAF on it and does no different with it on or off.
There is nothing wrong with SD, I ran my stroker setup SD because I was maxing out the flow limits of the PCM NA and didn't want to scale the injectors to make it work, so I ditched it to run SD. However on setups that are more mild it's no benefit really to delete it. My Formula which is a cam only car has an OE 85mm truck MAF on it and does no different with it on or off.
