Background:
Previous posts have discussed comparing the APR PEX intake with the Blaze ATOM Race and the Racingline R600 intake with the Blaze ATOM Race.
Both the APR and Racingline intakes performed similarly to the Blaze ATOM Race, a decidedly different result from conclusions presented in the Equilibrium Tuning (North America exclusive seller of the Blaze intake) Facebook group, where both the APR and Racingline intakes were mismatched to a stock-size inlet elbow when compared to the Blaze ATOM using a hybrid turbocharger.
The subsequent logical comparison is of the modified stock GTI intake with the Blaze ATOM Race. This post compares the boost curve and wastegate duty cycle of a Mabotech M520h hybrid turbocharger when the Mk7 GTI is equipped with a modified stock airbox and the Blaze ATOM Race V2 aftermarket intake.
Test Process:
The Mk7 GTI stock airbox is modified by removing the snow guard/air baffle in the lower half, adding an opening in the lower half, opening the front driver side of the air duct, and covering the rear passenger side opening. An MST inlet hose replaces the stock accordion hose, and the MST V2 hybrid turbo inlet elbow replaces the stock turbo inlet elbow.
Notably, the stock Mann air filter is retained. I presently do not have an aftermarket panel air filter to test with. In the past, it has been shown that an aftermarket panel filter increases airflow compared to the stock air filter. The airflow increased by 5% in the test with the aftermarket air filter, a percentage increase that is also found when using the hybrid adapter (See flow bench data section below).
The modified stock airbox is installed on the GTI to record performance data on the street during a series of full-throttle third gear pulls.
Other components remain the same as the tests of the APR, Blaze, and Racingline intakes:
- Russell Road & Racing E30 Tune
- Mabotech M520h hybrid turbocharger
- aFe Power Charge Pipes
- Mabotech Stock Mount IC
- MPI / RS3 LPFP / HPA HPFP
- Baun Performance 4″ GESi Cat DP / 3.5 ” mid-pipe
- AWE track exhaust
Test Results:
An overview of the test session is shown below.
The data previously recorded using the Blaze ATOM Race V2 intake will be used to compare it with the modified stock airbox.
The outside air temperature during the modified stock test is similar to that during the Blaze test.
The intake air temperature during the modified stock test is similar to that during the Blaze test.
The boost curves are similar for both intakes, with a small (0.4 psi @ 6600 rpm) drop occurring with the modified stock intake.
The turbocharger wastegate duty cycle is similar until approximately 6000 rpm, where the higher airflow reveals a difference in the pressure drop. The modified stock intake causes the wastegate duty cycle to increase, correlating with the decrease in boost pressure.
Flow Bench Data:
To estimate what will happen if the Mann air filter is replaced with an aftermarket panel filter, the modified stock airbox with Mann filter is flow tested. Previously, the modified stock intake was flow tested using the 034 Motorsport panel filter, a product I no longer have.
Note: The image above is of a variation of this test, where the Racingline inlet hose and Epman elbow replaced the MST inlet hose and MST V2 elbow. I did not take a picture of the intake when the MST parts were tested.
The chart below shows how the flow rates of the variations of the modified stock airbox compare with that of the Blaze ATOM Race.
The Blaze ATOM Race has the highest airflow rate but is within the measurement margin of error with the modified stock intake when fit with the 034 Motorsport panel filter.
The modified stock intake with Mann filter flows 24 CFM less than the 034 fitted configuration. This equates to a 5% gain in airflow from the aftermarket filter, a change consistent with the previously referenced test.
These results suggest that the modified stock intake, when equipped with a high-flow aftermarket panel filter, will support boost and wastegate duty cycles similar to those measured using the Blaze ATOM Race intake.
Conclusions:
The tested intake’s impact on boost pressure was approximately 0.4 psi @ 6,600 rpm between the modified stock GTI airbox and the baseline Blaze ATOM Race V2 intake.
An aftermarket panel filter allows further modification of the stock airbox but was not part of this test. Previous tests of the performance gain from an aftermarket filter showed that a 5% increase in airflow is possible. Bench tests of the modified stock airbox with an aftermarket filter showed flow rates equal to the Blaze ATOM Race, within the measurement margin of error, when utilizing a hybrid turbocharger adapter.
Based on the bench test results, the slight difference in WGDC detected between the modified stock and Blaze intakes during the street testing would likely be eliminated by using an aftermarket air filter in the modified stock airbox.
Equilibrium Tuning claims that the Blaze ATOM Race is “one of the best-performing and flowing options on the market as verified by independent testing,” but this is dubious given that the Mk7 GTI stock airbox can be easily and relatively inexpensively modified to equal the performance of the Blaze ATOM Race.
I’m running a BMC filter with standard airbox , 450kw. Bang for your buck I’d stay away from expensive intakes.