MAF swap/upgrade

[offroadrider12]

Looking at the intake on my 08 trailblazer 4.2L engine, it appears the OEM MAF housing appears to be the choke point on the factory intake.

The 5 pin connector on the MAF appears to be the same as the one on my 2003 sierra with a 5.3L. The 5.3 uses a 3" MAF housing.

Has anyone successfully swapped & tuned for a 5.3L MAF?

If I don't go this route I also considered getting Limequats MAF Flange and welding it to a piece of 3" aluminum intake pipe to use the 4.2 MAF in a bigger opening.

From the designs of the MAF it appears to my eyes that the 5.3 MAF would flow better than the 4.2 MAF in a 3" pipe.

Anyone have input?

 

[AtlWrk]

The shop schematics show the order of the pins in the MAF connector are different between the 4.2L and 5.3L (not a hard problem to correct). The real question is whether the 4.2L knows how to read/interpret the 5.3L MAF sensor? It probably can, even though they are slightly different styles but I dunno.

The easiest and fairly common route is to simply put the existing MAF into a larger tube and tune to adjust accordingly. Usually this is part of replacing the entire intake with a "performance" intake.

That being said, IMO, even that's not going to be worth it. I know it looks restrictive because of how the tube necks down around the sensor and the blockiness of the sensor itself. But, unless you're racing or otherwise spending a lot of time at WOT the stock system flows just fine. On the flip side, a larger tube around the MAF (even with a tune) necessarily reduces the resolution of the MAF making it harder for the PCM to get accurate information about relatively small variations in flow. I can easily imagine low end torque and fuel economy suffering.

Would be interesting to look at pressure drops at various points along the intake at idle and 4000rpm to quantitatively show where the restrictions are

 

[limequat]

Low load fueling is done by the map sensor.
I run a 4" maf tube, with no resolution problem. The only issue with 3" would be dialing it in.

 

[offroadrider12]

Low load fueling is done by the map sensor.
I run a 4" maf tube, with no resolution problem. The only issue with 3" would be dialing it in.

Which route would you suggest? You would likely be the one doing the tuning. It was me that spoke to you on the phone yesterday. Would the screened 5.3 MAF have better resolution?

 

[limequat]

Which route would you suggest? You would likely be the one doing the tuning. It was me that spoke to you on the phone yesterday. Would the screened 5.3 MAF have better resolution?

I don't think you'll have problem with resolution either way.
But I definitely think you'll get better results overall with the 5.3 maf tube (assuming it fits right).
With the 5.3 tube, I just copy the MAF table from a V8 and paste it into your tune. With a hand built tube, it takes 1-2 hours of driving, monitoring fuel trims, and recalibrating.

 

[offroadrider12]

The shop schematics show the order of the pins in the MAF connector are different between the 4.2L and 5.3L (not a hard problem to correct). The real question is whether the 4.2L knows how to read/interpret the 5.3L MAF sensor? It probably can, even though they are slightly different styles but I dunno.

The easiest and fairly common route is to simply put the existing MAF into a larger tube and tune to adjust accordingly. Usually this is part of replacing the entire intake with a "performance" intake.

That being said, IMO, even that's not going to be worth it. I know it looks restrictive because of how the tube necks down around the sensor and the blockiness of the sensor itself. But, unless you're racing or otherwise spending a lot of time at WOT the stock system flows just fine. On the flip side, a larger tube around the MAF (even with a tune) necessarily reduces the resolution of the MAF making it harder for the PCM to get accurate information about relatively small variations in flow. I can easily imagine low end torque and fuel economy suffering.

Would be interesting to look at pressure drops at various points along the intake at idle and 4000rpm to quantitatively show where the restrictions are

Can you post the difference in the order of the pins or send me a link to it please?