More Modified Stock Airbox Testing


Over the weekend I came across a not-so-uncommon exchange. A Mk7 owner has an intake product in mind that they’re considering purchasing and a representative from vendor EQT suggests that instead of what they’re thinking about buying, the owner should spend “a small bit more” and buy a product EQT is selling instead.

I asked the EQT representative what benefit the consumer would get from the extra cost.

The response was a “ha-ha” emoji and no answer to the question.

The exchange has some interesting insights into how people at EQT conduct business, which I may come back to with a future post, but it made me think about the recent flow test I had done with a modified stock airbox.

The stock airbox had fared well against a number of aftermarket intakes using a hybrid turbo adapter, and I left that post considering a future test where I would use similar modifications to the stock airbox and compare the results to aftermarket intakes using an IHI-size turbo adapter.

Before you know it, along comes somebody from EQT that piques my interest in putting the stock airbox back up for testing.

For this comparison, I decided to leverage the 034 Motorsports Insuction bundle. 034 supplied me with this setup for testing a while back and it has proven useful to have around.

Since the idea originated with a Mk7 owner interested in intake options I decided to keep the system under test aligned with a package kit, and the fact that 034’s panel filter flows very well, as does their Turbo Inlet Elbow (with a stock size turbo) it was a good fit for this test.

An added dimension of the comparison, as James at EQT brought up, is the cost differential of the products.

The 034 Motorsport Insuction bundle rings up at $237.54

034 Motorsport Insuction Bundle
034 Motorsport Insuction Bundle Price

This compares to the EQT / Blaze ATOM V2 at $606.13

EQT Blaze ATOM V2 Price
EQT Blaze ATOM V2 Price

Test Procedure:

Previously the Blaze ATOM V2 was flow tested with a stock turbo adapter using the Blaze stock turbo insert that fits into the turbo flange.

Blaze Performance ATOM V2 Intake Insert Test
Blaze Performance ATOM V2 Intake Insert Test

The Blaze ATOM V2 flowed 393 CFM @ 28″ of H2O.

The 034 Motorsport parts are installed with a modified Mk7 stock airbox and duct. The stock system has the following modifications in addition to the 034 Motorsport parts:

  1. Driver’s side of air duct cut open.
  2. Back side of the passenger side of air duct covered.
  3. Snow guard / air baffle grate removed from airbox lower half.
  4. Slots cut into the lower half of the stock airbox side.
Mod Stk Cutout - 034 Insuction parts
Mod Stk Cutout – 034 Insuction parts

Noteworthy changes with this modified stock setup compared to a previous test I conducted with a modified stock airbox are the 034 Motorsport panel filter, which flows slightly more than my aFe panel filter, and some cuts to the side of the stock airbox, which were found to increase airflow slightly.

George E. Stock Airbox Modification
George E. Stock Airbox Modification

The flow bench calibration is checked and the stock intake is assembled and attached to the bench using an adapter that simulates the compressor housing inlet of the stock IHI turbochargers.

This is the same adapter used when testing the Blaze intake.

The airflow through the stock intake is measured at a depression of 28″ of H2O.

Test Results:

The modified stock intake with 034 Motorsport Insuction bundle flowed 393 CFM @ 28″ of H2O.

This result is shown on the chart below along with other intake setups that have been tested using the stock IHI adapter.

Intake Airflow - Stock Turbo Inlet
Intake Airflow – Stock Turbo Compressor Inlet


A modified stock Mk7 GTI airbox is equipped with parts from the 034 Motorsport Insuction bundle and the intake is flow tested using a simulated IHI-size turbo compressor inlet resulting in a flow rate of 393 CFM @ 28″ of H2O.

This result compares well with aftermarket intakes that have been flow tested using the simulated IHI compressor inlet.

As to the question of what benefits a person gets for the additional cost of the full aftermarket setup, if the system is paired with a stock turbocharger there is no apparent improvement in pressure losses across the intake compared to the stock airbox modified as described above.


2 thoughts on “More Modified Stock Airbox Testing”

  1. Appreciate your work! I like how you are always trying to eliminate variables and produce accurate results. It’s not about being right it’s about getting it right.

    I saw a video recently that mentioned a flow bench isn’t an accurate way to measure a products effectiveness in our vehicles. Here’s the video below, if you have some time tonight check it out!

    1. Thanks Nick!

      I have seen the video. Without touching on the technical aspects of what they claim, consider these things. 1) The title “Everyone is measuring airflow WRONG” Everyone is wrong? Click-bait anyone. 2) Everyone includes OEM manufacturers, Race Teams with a lot of money on the line, organizations that can hire smart people, does it make sense that they would all be measuring airflow wrong and it took Banks Power to figure this out? 3) Towards the end they provide a link to the product they sell that will help you measure airflow “right“. — Infomercial.

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