Grate Test - Airbox Entrance Strips

Snow Guard Water Test – Part 3

Background:

In the spirit of “My experience owning a Mk7 GTI”, this post starts with the motivation to conduct a test to determine if the “snow guard” helps to prevent water from reaching the air filter.

Like a number of tests, this one began as a discussion with some other GTI owners about a part on the car and it’s function.

Snow Grate Test Motivation
Snow Guard Test Motivation

The first step in the testing process is asking questions and gathering information. Finding out what experiments have previously been conducted can help to gain insight into the question of interest or make a test process better. It appeared that I might find some previous results to evaluate:

Snow Grate Evidence Search

After searching online and watching ten YouTube videos about “snow guard” installation I hadn’t found any information that proved or disproved the “snow guard” affecting the passage of water to the air filter. I went back to the discussion to see if I could get direction to the information.

  • Yes there is evidence look at tuners online recommending not do it and why. All of them I have seen advise against it.
  • You don’t want to believe me do your own research. I will warn you though on Reddit there are several people making the same claims as you, but the ones that are tuners, mechanics, or work for vw all seem to come to the same conclusion and that’s that it’s not worth it to remove it.
  • dude, just google it almost every tuner and mechanic advise against it. I don’t need to research anything for you because you’re too lazy or too stubborn.

Hooray for Social Media research!

Hooray!

I never found any evidence of the “snow guard” stopping water from reaching the air filter, but if you have a link to this information please use the comments section below to provide me with a link.


Test Process:

Previously I made two posts about this test. The first was with my installed aftermarket intake, and the other showed how I would setup the stock intake to test it with the snow guard removed.

After seeing some signs of water at the inlet to the Eventuri intake I decided to install the GTI stock airbox and add some water indicator tape to it to see if water could reach the air filter.

If water can reach the air filter then it is possible that the “snow guard” might also prevent water from reaching the air filter.

With the water indicator tape installed along the stock intake I waited for a rainy day to take the GTI out for a drive to see if water would reach the airbox.

Once I had a rainy day the GTI was driven at varying speeds up to 70 mph. It was occasionally driven behind other vehicles with the idea that water being sprayed up from tires might enter the air intake.

Note: There might be some unusual condition that could also potentially result in water making it into the intake that was not experienced during this test. I.e. During the discussion, it was suggested I could use a garden hose to spray water into the grill of the car.

Test Results:

Within the air duct, the tape that is behind the opening on the driver’s side shows there was water present because the color has changed from white to red. The other three strips do not show signs of water being present, the tape color has stayed white. This is consistent with the results that were seen with the Eventuri intake.

Grate Test - Air Duct Strip Results
Guard Test – Air Duct Strip Results

Looking down the intake duct into the bottom of the airbox there are no indications that water reached this location.

Grate Test - Airbox Entrance Strips
Guard Test – Airbox Entrance Strips

Another look from the air duct down into the airbox.

Grate Test - Airbox Entry Strips
Guard Test – Airbox Entry Strips

Looking inside the bottom of the airbox there is no indication that water has reached this area.

Grate Test - Airbox Lower Half Strips
Guard Test – Airbox Lower Half Strips

Checking the indicator tape that is attached to the bottom of the air filter there is no sign that water reached the air filter.

Grate Test - Air Filter Strip Results
Guard Test – Air Filter Strip Results

Conclusions:

Under normal driving conditions in the rain, there is no indication that water entry into the airbox is a problem.

Because water is not reaching the airbox, the presence or absence of the snow guard will not affect water getting to the stock air filter when the GTI is operated as described in this test.

References:

Holding place for links to similar tests.

7 thoughts on “Snow Guard Water Test – Part 3”

  1. I have been waiting for this follow-up after seeing water in test 2. Great to see the expected results here and I love your sentiment about social media research.. My curiosity, since it is referred to as snow and not rain guard, is if this test changes anything when driven over deep snow.

    Thank you again for making an attempt to provide factual information to the MK7 community. Your testing has directly influenced multiple of my modification decisions.

    1. Thanks for that feedback! In the VW Parts catalog, it is referred to as an air baffle. How it affects snow entry would be interesting to learn. With snowflakes being lighter than water droplets they might make it further into the intake.
      Air Baffle

  2. Jeff, great info.

    Mine’s removed but I’m indifferent as I can’t tell anything noticeable performance wise. I guess I’m not shooting myself in the foot leaving it out.

    Aside, I recently purchased an IC after reading your IC threads. Not your bench flow champ by any means but your data was helpful in narrowing it down. Thanks!

    1. I’m glad to know the information was helpful. The flow test needs to be weighed against cooling performance, in addition to considering that differences in CFM are in some cases not that significant in their effect on the turbo performance.

  3. Thank you for the diligence in testing this in addition to all the other tests you have conducted. You are a true benefit to the community helping us separate the wheat from the chaff and making informed purchase decisions.

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