Grate Test - Air Duct Strips

Snow Grate Water Barrier Test – Part 2

Background:

A hypothesis is that the snow grate inside the Mk7 airbox can help to keep water droplets from reaching the air filter.

A previous post addressed a preliminary check to see if this hypothesis warranted a closer look, which I decided it did.

The next step is to install water contact tape at several locations within the stock air intake to check if water enters the intake.

Grate Test - Air Duct Strips
Grate Test – Air Duct Strips

The strips on the lower half of the airbox.

Grate Test - Airbox Strips
Grate Test – Airbox Strips

A strip is placed at the bottom of each side of the inlet to the airbox.

Grate Test - Airbox Strips
Grate Test – Airbox Strips

Looking down into the airbox from the air duct.

Grate Test - Airbox Front Strips
Grate Test – Airbox Front Strips

Water indicator tape locations along the underside of the air filter.

Grate Test - Air Filter Strips
Grate Test – Air Filter Strips

Now I will wait for a rainy day.

4 thoughts on “Snow Grate Water Barrier Test – Part 2”

  1. Hi Jeff, quick question. Are you going to repeat the test with the snow grate installed with new tape on the air filter? Will help prove that even with the grate that water does/doesn’t get through.

    Love your research by the way, keep up the good work.

    1. Thanks!

      It depends on the outcome of this next step. If there isn’t any sign that water is getting to the air filter without having the grate installed I don’t plan to conduct the test again with the grate installed.

    1. Thanks for pointing that out.

      I commented on their Facebook page about the lack of a detectable difference on the dyno with back-to-back pulls. That’s not a surprising result using that measurement device in the manner they conducted the comparison. Removal of the air baffle has a very slight effect on the pre-turbocharger pressure drop. The first measurement I made of the baffle was without the turbo inlet elbow in place. I performed a follow-up with a more typical “aftermarket” setup and included the turbo inlet elbow. You can see that the difference goes down with the addition of the TIP. There is still an improvement, but it is small, only 6 CFM during the test.
      For reference, a 6 CFM change at the test condition I chose equates to 0.03 psi – I wouldn’t expect a dynamometer to be capable of detecting such a subtle change.

      Oddly though, they attributed the 4000 RPM range 8 HP/14 NM dip to the baffle, which is exceedingly unlikely, for the very reason that it has such a minimal effect on the airflow.

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