70mm MAF housing for $12 - with scaling

John M · **Joined:** Sun Jun 07, 2009 9:04 pm **Posts:** 12

I'm using a Spectre brand intake from AutoZone that costs a whopping $12 and wanted to share it. Their specified inside diameter is actually 73mm and the scaling shows it to be somewhere between the two.

Attachment:

intake2.jpg [ 82.98 KiB | Viewed 4952 times ]

The rubber coupling on the right side comes with the APS inlet pipe. It would be easy to duplicate from off-the-shelf parts also at the parts store if you needed to.

The housing is indeed plastic, but as long as you're not using a blow-through setup it should be more than adequate. It beats paying $100-200+ for 8 inches of pipe.

Scaling:

Code:

[Table2D]
0.90   0.94   0.98   1.02   1.05   1.09   1.13   1.17   1.21   1.25   1.29   1.33   1.37   1.41   1.48   1.56   1.64   1.72   1.80   1.88   1.95   2.03   2.11   2.19   2.23   2.34   2.42   2.54   2.66   2.77   2.89   3.01   3.12   3.24   3.36   3.48   3.59   3.71   3.83   3.95   4.06   4.18   4.30   4.41   4.49   4.57   4.61   4.65   4.69   4.73   4.80   4.88   4.96   5.00
1.56   1.80   2.05   2.30   2.57   2.88   3.23   3.62   4.05   4.49   5.00   5.67   5.94   6.57   7.95   9.44   10.51   12.24   14.09   16.19   18.53   21.16   24.06   27.24   29.00   34.56   38.65   46.49   54.22   62.62   71.79   81.79   92.34   103.77   116.19   129.69   144.28   159.94   176.70   194.69   214.03   234.95   257.49   281.73   298.89   317.11   326.62   336.36   346.35   356.56   377.37   399.03   421.57   433.31

The original scaling came from NSFW and I then modified it until the Learning View corrections were all within 1-2 grams. Note that I have NOT verified the top end with a wideband yet -- you'd want to do that yourself anyway. This is a safe beginning that should get you very close to the ideal scaling.

wrxsti-l · **Posted:** Sun Oct 25, 2009 4:17 am

I used one of these for almost a year and thought I'd post a little further info too.

They are NOT good for prolonged use on our cars in stock form. IMO they are more of a stop-gap solution (ie. if you have just installed a larger turbo and need a larger MAF housing to suit for the least amount of money until you can save some cash for a good one, then this is your solution) unless you improve their ability to withstand heat.

Basically, the plastic used to manufacture the housing is not very heat resistant, and after a short period of time, it will start to deform due to engine bay heat, and this will throw out your MAF Sensor Scaling. The first time I noticed it had started to deform was when I inspected the pod filter after about 6 weeks (ie. to see how clean it was). When I removed the pod, the ends of the Spectre MAF housing had deformed at each end (ie. where the clamp held the POD filter in place and where the housing was clamped to the turbo inlet coupler).

Anyhoo, what you need to do if you use it, is one of the following:

Wrap it in heat wrap (the stuff used on headers/exhausts)
Wrap it in heat reflective tape
Spray it with heatproof paint

I did option 3, and it held up ok for almost a year - and although it still deformed where the clamps were, it didn't deform too much more then it had already. If I had the time over, I would have sprayed it with heatproof paint and then wrapped it with reflective tape before the first use, but I have a KS Tech housing now, and it is the bees knees

Leslie

John M · **Joined:** Sun Jun 07, 2009 9:04 pm **Posts:** 12

Was yours mounted in a hotter area under the hood? I can see it overheating if it was closer to the turbo but that area doesn't seem to have much potential for high heat.

Mine has been in place for almost 1000 miles with no issues, in weather ranging from 40 to 100 degrees.

wrxsti-l · **Posted:** Tue Oct 27, 2009 7:33 am

Mine was mounted exactly the same as the one in your pic - I even have the APS inlet and coupler - and it still deformed due to heat - which is why I suggested insulating it as per my previous post

I have it out in the shed, so I'll go take a photo of it to show how much it deformed over the 12 months I had it installed (approx 10 of which I had it painted in heatproof paint).

Leslie

LittleBlueGT · **Joined:** Tue May 01, 2007 12:02 am **Posts:** 521

wrxsti-l wrote:

Mine was mounted exactly the same as the one in your pic - I even have the APS inlet and coupler - and it still deformed due to heat - which is why I suggested insulating it as per my previous post

I have it out in the shed, so I'll go take a photo of it to show how much it deformed over the 12 months I had it installed (approx 10 of which I had it painted in heatproof paint).

Leslie

As always, your info is appreciated.

John M · **Joined:** Sun Jun 07, 2009 9:04 pm **Posts:** 12

Just an update -- the intake has been on the car over a year now with no issues. It hasn't deformed or otherwise failed in any way. This was one of the hotter summers we've had too, with temps regularly at 100 or above throughout June, July, and August.

I'm slowly tweaking the higher MAF values and will post the final calibration when I'm done.

jon7009 · **Posted:** Thu May 14, 2015 2:26 am

When I first tried this, I was compensating in the maf area from an issue needing more tip-in. After figuring out I needed more tip-in I restarted with the original scale and quickly found it was close enough to be acceptable, but I wanted it more refined of course.

My adjusted table now is not that much different, some changes in closed loop area.

Code:

[Table2D]
0.89996337522   0.940017696345   0.979995723525   1.019973750705   1.0500335650350001   1.090011592215   1.129989619395   1.169967646575   1.2100219677   1.24999999488   1.2899780220600001   1.330032343185   1.370010370365   1.409988397545   1.480026239055   1.559982293415   1.64001464172   1.71997069608   1.8000030443850001   1.88003539269   1.949996940255   2.03002928856   2.10998534292   2.190017691225   2.229995718405   2.3400115870950002   2.419967641455   2.53997801694   2.659988392425   2.770004261115   2.8900146366   3.010025012085   3.11996458683   3.2399749623150003   3.3599853378   3.479995713285   3.5900115819750003   3.71002195746   3.830032332945   3.949966414485   4.059982283175   4.17999265866   4.300003034145   4.410018902835   4.489974957195   4.5700073055   4.60998533268   4.64996335986
1.556396484375   1.8035888671875   2.05078125   2.2979736328125   2.5726318359375   2.8839111328125   3.2318115234375   3.6163330078125   4.046630859375   4.486083984375   4.998779296875   5.6671142578125   5.9417724609375   6.573486328125   7.94677734375   9.48486328125   11.316247558593751   12.85400390625   14.794921875   16.9921875   18.9971923828125   21.6888427734375   24.664306640625   27.91786193847656   29.72900390625   35.425186157226555   39.61990356445312   47.652740478515625   55.57296752929687   64.18762207031249   73.58116149902344   83.83804321289061   94.64859008789062   106.36001586914061   119.09431457519531   132.93594360351562   147.88490295410156   163.94119262695312   181.11419677734375   199.5540618896484   219.38278198242185   240.82557678222653   263.92936706542963   288.7692260742187   306.364517211914   325.03898620605463   334.7891235351562   344.7644805908203

thatsbk · **Joined:** Fri Dec 02, 2016 8:42 pm **Posts:** 3

Did you ever end up adjusting your MAF scaling in open loop with this MAF housing?

jon7009 · **Posted:** Mon Feb 13, 2017 9:47 pm

I ended up going speed density and throwing this thing away, after some heat cycles you can see how weak the plastic is.

RomRaider

70mm MAF housing for $12 - with scaling

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