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Making my own custom intake and it has all gone according to plan, i test fit it and it all fits in the small space you have to work with, surprisingly does fit over the battery and hood will close. With stock piping being 2.5" at the MAF sample tube, and throttle body being 2.75, i have a feeling this engine starves for air at WOT. It seems it was designed for common city driving (no long periods at cruise, infrequent WOT, low speeds, starts and stops), emphasizing as much low end torque as possible for good driveability, especially in automatic flavor.
As such, i went with 3" ID, 3.5" OD ABS pipe, ABS is desirable for an intake because it is light, will not hold heat, can be cut and "machined" or manipulated easily, and is also cheap to boot. With intakes the largest size pipe that fits within the confines of engine bay is the best, provided the transition to throttle diameter is smooth and relatively gradual, and bends are avoided as much as possible. Since plastic has poor radiant heat reflection characteristics i will be wrapping piping with reflective insulation when i finalize it. Getting the MAF to seal and secure to the pipe was easy, sensor dimension is about 1 3/8" x 3/8", i marked it out and used small drill bits to "machine" it out, the rubber seal on the flange of MAF will seal any small imperfections. Fastening was easy too, i slid the MAF into the pipe where it would sit, then drilled shallow holes using the MAF as a guide, making the pilot holes with a bit that is slightly smaller than the original MAF bolts. Then i just started the bolts into the plastic by hand and once they started making their own threads, used a ratchet to go right down into the plastic till they bottomed out, ABS is soft enough that the bolts are self tapping in a fashion and will create their own threads.
Now that's what i did. Now i need a cheap way of calibrating the MAF to match the increased diameter and lower sample velocity. It runs dangerously lean with this new intake due to this, enough that it will not idle. Still, i HAD to hear this thing, so i unplugged the MAF. The computer will then revert to predefined fuel tables that are known to be safe ( ie, really rich across the board). Sounds like a Subie at low RPM and high load! Loud as hell. It was addictive just driving around, so many people looked! Though i was running with no filter so it will probably quiet down once i get one.
Any ideas about calibrating an MAF WITHOUT any software? I want to get Osiris for this but i have to wait for that, my 87 Porsche 928 S4 project is taking priority right now. Anything to at least get the AFR at least roughly close to target, to make this driveable?
As such, i went with 3" ID, 3.5" OD ABS pipe, ABS is desirable for an intake because it is light, will not hold heat, can be cut and "machined" or manipulated easily, and is also cheap to boot. With intakes the largest size pipe that fits within the confines of engine bay is the best, provided the transition to throttle diameter is smooth and relatively gradual, and bends are avoided as much as possible. Since plastic has poor radiant heat reflection characteristics i will be wrapping piping with reflective insulation when i finalize it. Getting the MAF to seal and secure to the pipe was easy, sensor dimension is about 1 3/8" x 3/8", i marked it out and used small drill bits to "machine" it out, the rubber seal on the flange of MAF will seal any small imperfections. Fastening was easy too, i slid the MAF into the pipe where it would sit, then drilled shallow holes using the MAF as a guide, making the pilot holes with a bit that is slightly smaller than the original MAF bolts. Then i just started the bolts into the plastic by hand and once they started making their own threads, used a ratchet to go right down into the plastic till they bottomed out, ABS is soft enough that the bolts are self tapping in a fashion and will create their own threads.
Now that's what i did. Now i need a cheap way of calibrating the MAF to match the increased diameter and lower sample velocity. It runs dangerously lean with this new intake due to this, enough that it will not idle. Still, i HAD to hear this thing, so i unplugged the MAF. The computer will then revert to predefined fuel tables that are known to be safe ( ie, really rich across the board). Sounds like a Subie at low RPM and high load! Loud as hell. It was addictive just driving around, so many people looked! Though i was running with no filter so it will probably quiet down once i get one.
Any ideas about calibrating an MAF WITHOUT any software? I want to get Osiris for this but i have to wait for that, my 87 Porsche 928 S4 project is taking priority right now. Anything to at least get the AFR at least roughly close to target, to make this driveable?