Background:
Recently, the temperature has been fairly cold, dipping down into the lower 40s (cold for central Florida).
I set out to log the GTI in the colder weather to see how the Shuenk IS48 would perform.
Procedure:
A full-throttle pull, starting around 2,000 RPM and concluding around 6,500 RPM, is made.
The fuel currently sits at E40, which I have a Russel Road & Racing ECU tune for. This tune pushes the wheel power to levels that prevent logging in third gear, and logging in fourth gear limits the amount of data that I can reasonably collect.
Vehicle Setup:
- Shuenk IS48 turbocharger with anti-surge compressor housing
- Russell Road & Racing ECU tune – E50
- Racingline R600 intake / Shuenk turbo inlet hose
- AMS Performance SMIC / Majesty FMIC – Bicooler
- PR Racing MPI / HPA HPFP / RS3 LPFP
- Trackslag catless DP / Baun Performance midpipe / AWE Tuning exhaust
- SSR Competition wheels
Results:
Outside air temperature at the time of logging was 44 degrees Fahrenheit. Intake air temperatures were in the mid-50s.
The boost pressure reaches 31 psi at 3000 RPM.
It’s unknown whether the “anti-surge” housing of the IS48 is addressing possible compressor surge, but the high boost pressure at low RPM shows no issues related to it.
Compared to a log made in warmer weather (83°F), the boost onset occurs sooner, and the wastegate duty cycle is reduced by approximately 10%.
Noise levels on the knock sensors are below the OEM stock thresholds.
Note: This tune was developed using E50, and the current ethanol content is lower than the tuned value at 40%.
Processing the acceleration data with the virtual dyno yields a peak wheel-horsepower estimate of 438 WHP.
This is consistent with previous results of the GTI configured similarly to the current setup.
Conclusions:
The Mk7 GTI equipped with a Shuenk IS48 turbocharger was logged in cold weather. Boost onset was shifted earlier by about 200 RPM compared to warmer weather, and the turbocharger wastegate duty cycle was reduced by approximately 10%.
The estimated peak wheel horsepower was 438, which is consistent with previous results for this setup.