New Project - Tuning my 3.4L for POWER

[insite]

here are a few notes from others as i went through the intake design process:

tholyoak

Keep in mind that the positioning of the MAF sensor in the intake track relative to the throttle body and the air filter is as important for MAF voltage to air mass calibration as the the diameter of the housing the sensor is placed in. The 5.2.2 DME cars are extremely sensitive to this.

blue2000s

Flow speed is irregular through a tube, fastest at the center fully developed, 0 at the walls. If the sensor is near a bend, diameter change or near a filter, it will be irregular (not the nice, parabolic velocity profile) and need to be tuned.

......it has to match the 996. If they dialed it in near a bend or filter, you have to do the same thing. And be in the same relative location to the bend with regards to the circumference of the tube. So it's not a matter of you picking a good spot to start from, it's you having to pick the same spot that the ECU expects.

[The Radium King]

i think the wideband 02 and afc initiative is fantastic and am really excited for the results, but in the interim perhaps look at revising your intake to see if any power gains result (with your wideband 02 you would be able to definitively determine what, if any, changes to maf readings this would effect). if the 996 maf housing is indeed +/- 3.25" ID then it is a direct match to a bmc 85; you could couple the maf housing direct to the end of the filter then elbow towards the throttle body. room is tight in there, however, and such a config may not fit (didn't for me) but i've since found that some room can be gained by pulling the insulation off the inside of the engine bay.

i'm in that process right now; my intake design is similar to yours (copied in fact) and i am looking to use the 987 airbox instead (3.25" ID) as it gets my maf housing closer to the filter as per oem. i also worry about vibration affecting readings from a maf that is hung out there instead of tied to the air box.

[insite]

not messing w/ the intake anymore. i think it's reasonable. the bigger issue IMO is calibration of the MAF w/ respect to the ECU's AFR maps. for me, i think getting rid of the giant airbox all together was a smart move. the BMC is slick & flows well; it also allows me to elbow over to cold air easily.

Originally Posted by The Radium King

i think the wideband 02 and afc initiative is fantastic and am really excited for the results, but in the interim perhaps look at revising your intake to see if any power gains result (with your wideband 02 you would be able to definitively determine what, if any, changes to maf readings this would effect). if the 996 maf housing is indeed +/- 3.25" ID then it is a direct match to a bmc 85; you could couple the maf housing direct to the end of the filter then elbow towards the throttle body. room is tight in there, however, and such a config may not fit (didn't for me) but i've since found that some room can be gained by pulling the insulation off the inside of the engine bay.

i'm in that process right now; my intake design is similar to yours (copied in fact) and i am looking to use the 987 airbox instead (3.25" ID) as it gets my maf housing closer to the filter as per oem. i also worry about vibration affecting readings from a maf that is hung out there instead of tied to the air box.

[jaykay]

Originally Posted by insite

here are a few notes from others as i went through the intake design process:

tholyoak



blue2000s

Yes so I have been wondering what will come about with the 987 air box in a 986 with a 986ish tune. The 987 MAF sensor is right around a bend and convergent section where as the 986 is not