Background:
Recently, I installed the Mabotech M600 turbocharger in my Mk7 GTI to collect boost onset data.
In this post, I present the initial data and compare it with two other Mabotech turbochargers that were previously installed in the GTI.
Test setup:
The turbocharger assembly consists of the M600 CHRA, the small compressor housing, and the small A/R turbine housing (0.58) – a combination that represents the production version of the turbocharger.
The GTI is set up as follows:
- Mabotech M600 (0.58 A/R turbine) turbocharger
- Russell Road and Racing IS48 E40 ECU tune
- Eventuri Intake
- MST Performance turbo inlet hose
- DBV2 turbo inlet elbow
- 034 Motorsport TMD
- aFe Power charge pipes
- Majesty Competition IC & FMIC
- Stock “Euro” intake manifold
- CC Design 4″ GESi cat downpipe
- CC Design 3.5″ catback exhaust
Test results:
The overview below shows the test session, including four full-throttle partial pulls.
The build-up of boost pressure at varying engine speeds is shown below.
The M600 data is analyzed, and the engine RPM range required for boost pressure to increase from 1 psi to 20 psi is calculated. This is called the Engine RPM Delta in the chart below (Y-axis). The engine speed when the boost pressure reaches one psi is recorded as the independent variable for plotting on the scatter plot. This value is used because engine speed relates to the amount of exhaust gas passing through the turbine, which affects how quickly boost pressure builds.
The chart below compares the M600 with the previously tested M520 (smaller turbo) and M720 (larger turbo).
Note: The M720 turbo was only operated catless, and the M600 is being tested with a GESi cat. This configuration difference does affect the results. Also, the ambient air temperature during the M720 test was 70F, whereas the M600 was tested at an ambient temperature of 88°F. This will also affect the results. Both factors slow the M600 turbo’s boost onset rate.
Conclusion:
I installed the Mabotech M600 turbocharger in my Mk7 GTI to record boost onset data. I compared an initial series of pulls with the Mabotech M520 and M720 turbochargers.
The M600 spools slower than the smaller M520 as expected. The M600 spools slightly faster than the larger M720, but two factors- the presence of a GESI cat and warmer ambient temperature conditions- negatively impact the M600 boost onset rate.
Next Step:
The GESi catalytic converter will be removed from the CC Design mid-pipe and swapped with a straight pipe for retesting in a catless configuration.
