Turbo Inlet Pipe Testing

1. Background

This project was started to evaluate the performance of a selection of Turbocharger Inlet Pipe (TIP) products.  Presently the only known source of performance data for some of these products is manufacturer supplied data and user accounts that typically consist of perceived performance changes.

MQB Turbo Inlet Pipe Flow Test
MQB Turbo Inlet Pipe Flow Test

2. Purpose

This test program will consist of taking measurements of the airflow passing through each test item to enable the evaluation of relative performance among the test items and absolute performance under the test conditions.  The results will show which Turbo Inlet Pipe allows the highest airflow under the test conditions.

3. Description of Equipment

3.1 Test Items

The TIP is a component located along the Mk7 GTI/R engine intake and connects the airbox to the turbocharger allowing filtered air to enter the turbocharger compressor housing.  All test items that are part of this program are built to function at a minimum with the IS20 or IS38 style compressor housing and stock size inlet hoses.  None of the test items have been modified from how they were delivered from the vendor.

A stock hose and top half of the airbox will be utilized to create a pathway for intake air to travel along to the TIP.  Note: The lower half of the airbox and filter will not be attached for the purpose of eliminating potential resistance along the pathway to the turbo inlet pipe.

An adapter made of a three inch silicone hose will be used to join the TIP to a flowbench adapter plate.

3.2 Test Instrumentation

A PTS flowbench will be used to generate airflow through the test items.  A PTS digital manometer capable of reading up to 36” of H2O will be used to measure the airflow through the flowbench.

PTS Flowbench
PTS Flowbench – Maximum airflow 600 CFM @ 28″ of H2O

4. Scope of Test

4.1 Test Envelope

Airflow testing by means of a flowbench is commonly performed at test depressions in the range of 10” to 28” of H2O.  For this test program all measurements will be recorded at a depression of 28” of H2O.

4.2 Tests and Test Conditions

Testing will take place in an enclosed garage with air temperature between 70 to 78 degrees fahrenheit.

4.3 Test Configuration

The turbo inlet pipe will be attached to an OEM inlet hose and to the flowbench by means of a straight silicone coupler and flowbench adapter plate.

4.4 Test Criteria

For a successful test there will be no leakage among the articles being subjected to airflow.  The test depression of 28” must be maintained within +/- 3 CFM while measurements are recorded.  A minimum of 10 measurements will be recorded for each test case to be successful.

4.5 Limitations to Scope

In operation it is expected that the MQB will generate intake airflow that ranges from 10 CFM up to 600 CFM (redline at 27 psi of manifold boost pressure).  The maximum airflow capacity of the PTS flowbench is approximately 600 CFM at 28”.

It is anticipated that several vendor test items that are available for use with the MQB will not be obtained for this test.

5. Method of Test

5.1 Preparation

Flowbench accuracy will be checked prior to collecting measurements by using a PTS calibration plate.  The flowbench will be operated in a draw-through configuration.  The flowbench will be operated before taking readings to perform a leak check.

The Mk7 intake will be assembled to replicate the arrangement found in service on the vehicle and clamps used to join the parts will be checked for integrity.  Orientation of test items and accessories will be checked and adjusted to maintain standardization between test cases.

5.2 Operational Procedure

Airflow through the test item will be increased until the test condition depression of 28” of H2O is attained and once airflow readings from the digital manometer stabilize ten (10) readings will be made.  The flowbench will then be shut off and the test article removed.  The ten readings will be averaged and the standard deviation will be determined.  The median value will also be determined and compared with the average to check for consistency.  If consistency is found among the data the average value will be used for reporting purposes.

6. Project Management

Availability of test items poses the most significant challenge to collecting comprehensive data. The following table summarizes candidate test items, vendor, vendor response to request, owner contribution, and links to each test case.

Test ItemVendorVendor ResponseOwner DonatedTest Status
Stock GTIVWn/aYesComplete
APRAudi Performance & Racingn/aYesComplete
UnitronicUnitronicn/aGolfMk7 Forum Member - GolfRRRRComplete
BMSBurger MotorsportsDeliveredn/aComplete
MSTMST PerformanceDeliveredn/aComplete
CTSCTSn/aGolfMk7 Forum Member - CracknessComplete
VWRDid not reply to requestTBDIncomplete
SpulenDid not reply to requestTBDIncomplete
DFG TuningDid not reply to requestTBDIncomplete
RamairDid not reply to requestTBDIncomplete

Note: Test Item column links to product description page if available.

7. Results

The following links are to pages detailing the progress of the testing effort:

The compiled results are presented below:

Note: In cases where an inlet hose is not identified the stock accordion hose is being used.  In general an aftermarket inlet hose results in 8-10 CFM gains over the stock accordion hose.

Results are broken into four groupings:

  1. Stock Accordion Hose with IS20/IS38 Adapter
  2. Aftermarket Accordion Hose with IS20/IS38 Adapter
  3. Stock Accordion Hose with Large Adapter
  4. Aftermarket Accordion Hose with Large Adapter
Mk7 TIP Airflow using Stock Accordion Hose
Mk7 TIP Airflow using Stock Accordion Hose

Mishimoto TIP Flow Test with Aftermarket Turbo Hose
TIP Flow Test with Aftermarket Turbo Hose

Stock Accordion Hose with Large Adapter
Stock Accordion Hose with Large Adapter

Flow Test – Large Adapter

Inlet Elbow Collection Airflow Uniformity Chart
Inlet Elbow Collection Airflow Uniformity Chart