Vargas Turbo Cold Side Charge Pipe Flow Test

Vargas Charge Pipe Test

Background:

Previously I have tested a few different charge pipe products from aftermarket vendors as well as the stock GTI parts. When I was contacted by Vargas Turbo about possibly testing their charge pipes I decided it would be interesting to see how a silicone charge pipe fared against the metal and plastic versions.

As a single piece silicone part the Vargas charge pipe connects the turbocharger to the intercooler, and intercooler to the throttle body, doing away with the hoses and one pair of hose clamps that the stock, and metal options, used.

Vargas Turbo Hot Side Charge Pipe Flow Test
Vargas Turbo Hot Side Charge Pipe Flow Test

Test Procedure:

Flow testing is performed on each charge pipe individually and then by joining the pipes with a small length of silicone hose. This short piece of hose is a substitution for the intercooler. The silicone joiner hose has less pressure drop than an intercooler, which should allow the test to better represent how well the charge pipes flow.

The charge pipes are attached directly to the flow bench using an adapter that is sized to fit inside of the charge pipe and the inlet of the charge pipe has a bell-mouth attached to help direct air smoothly into the pipe/hose.

The flow bench is operated at a depression of 28″ of H2O and the airflow through the pipe is measured at this depression.

Vargas Turbo Hot & Cold Side Charge Pipe Flow Test
Vargas Turbo Hot & Cold Side Charge Pipe Flow Test

Test Results:

Airflow for each pipe arrangement are listed below:

  • Hot side charge pipe: 392 CFM
  • Cold side charge pipe: 595 CFM *
  • Both charge pipes: 362 CFM

Note: The cold side pipe (*) was tested at 26″ of H2O and extrapolated to 28″

These measurements are compared with the stock GTI charge pipe in the chart:

Vargas & Stock GTI Charge Pipe Flow Test
Vargas & Stock GTI Charge Pipe Flow Test

A summary of all of the charge pipes that have been flow tested is shown in the next series of charts:

Charge Pipe Summary – Hot Side Pipe Flow
Charge Pipe Summary – Cold Side Flow
Charge Pipe Summary – Combined Pipe Flow

Conclusions:

The Vargas Turbo silicone charge pipes for the Mk7 GTI were flow tested using a flow bench. Compared to the stock GTI charge pipes the Vargas Turbo product produced gains of 43% on the hot side, 30% on the cold side, and 34% with joined charge pipes.

Vargas Turbo Cold Side Charge Pipe Flow Test
Vargas Turbo Cold Side Charge Pipe Flow Test

References:

Vargas Turbo Technologies product page


Airflow Sensitivity Investigation

While testing the charge pipes a couple of different arrangements of bell mouth to charge pipe were tried and the results demonstrate the ability of the flow bench to differentiate subtle changes.

Bellmouth over hose
Bellmouth over hose
Bellmouth flush with hose
Bellmouth flush with hose
Bellmouth inside hose
Bellmouth inside hose

The Vargas hot side charge pipe was tested with each configuration of the bell mouth to the hose and shown above and the results are summarized in the chart.

Bellmouth Airflow Investigation

A couple of points to make about the results as they apply to optimizing and testing of these parts:

The improvement in airflow in the “flush” and “inside” cases were 5.5% and 13.6% versus the “over” setup. Relatively subtle changes to the arrangement of the parts can result in decent airflow gains.

Looking at the images of the “over” and “flush” cases does not give the impression that there would be an ~ 20 CFM difference in airflow. This is an example of the type of small changes that the flow bench is able to pick out.

This is very handy when performing detailed work, such as porting an intake manifold or cylinder head, but can give an impression that there is a large change in performance if care is not taken to consider how the resolution of the flow bench differs from other measurement tools that one may be more familiar with.

5 thoughts on “Vargas Charge Pipe Test”

    1. For the test you’ve linked, I had the aFe turbo outlet hose that is sized to work with the stock TMD. That was not what I had ordered, I had ordered the larger TMD and hose option. They made a mistake when I placed the order and then there was a backorder that took a couple of months to fulfill. So in the interim, I tested what I had. Since that time I have done another test with the aFe Bladerunner pipes, using the larger inlet hose, which produced different results. I have not gotten around to writing a post to describe the test, but on this page, I have used the most recent aFe test results in the charts.

  1. Hi Jeff,
    Would there be value in testing the total flow of an intercooler (standard or otherwise) with both pipes attached, and comparing standard vs Vargas? I have always wondered how much potential airflow gain there can be with aftermarket charge pipes, considering the somewhat larger airflow restriction of the intercooler? Regards, Craig

      1. I went away from using the intercooler mostly because it is easier to test without it. I also had a concern that the intercooler would lower the overall airflow and make differences less apparent. I think it is valid to test it with the IC, I just didn’t see a benefit to doing so.

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