Background:
A previous post addressed collecting boost onset data with the Mabotech M600 turbocharger. This post presents the boost onset after removing a GESi catalytic converter from the exhaust system.
Test Setup:
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″ catless downpipe
- CC Design 3.5″ catback exhaust
Boost onset data is logged in third gear, varying the starting engine speed from around 1,500 to 3,000 RPM.
Test Results:
Removing the catalytic converter correlated with a left shift of the boost onset curve.
Next, the boost onset data is compared with the previously logged Mabotech M520 turbo.
The M600 takes 200-500 RPM longer to reach 20 psi than the smaller M520, depending on the starting engine speed.
Conclusions:
The Mabotech M600 turbocharger was tested to measure boost onset in third gear, and the data was compared with the same vehicle setup with the addition of a catalytic converter.
The RPM range for boost to build from 1 to 20 psi was reduced by approximately 100 RPM with the removal of the catalytic converter.