Background:
It’s been almost two years since I conducted a test with a prototype turbocharger that Shuenk had assembled, featuring a speed sensor to collect data on an IS38+ variant with a larger compressor wheel.
Recently, Shuenk introduced an IS48 turbocharger with a compressor wheel based on the Audi S4 3.0 TFSI compressor, which increases the inducer diameter by 3 mm over an IHI IS38 and the compressor exducer by 5 mm.
This turbocharger has the option of selecting an anti-surge ported shroud compressor housing.
Interested in seeing how this model performs, I coordinated with Shuenk to obtain a “super core” version for testing on my GTI.
Shuenk IS48 Turbocharger
As mentioned, the compressor wheel of the IS48 turbocharger is larger than that of an IHI IS38. The purpose of the larger compressor wheel is to allow for the swapping of this turbo for an IS38 or IS38+ and retain the IS38 tune, while operating the turbo at lower RPM, which should alleviate some stress on the bearings.
Additionally, the power levels of “tuned” IS38s are near the limit of what the turbocharger can support, and those power levels are where the Audi S4 3.0 turbo is intended to operate ‘efficiently.’
The IS48 retains the Mixed Flow turbine, a blade design that shifts peak turbine efficiency to a lower blade speed ratio compared to radial flow turbines.
I received a “super core” version of the turbocharger, which consists of the CHRA and cold side. The IS38 turbine housing can be reused in this case.
The assembled IS48 turbocharger is shown below, along with the silicone inlet hose to fit the larger compressor cover and a do88 turbo outlet hose to join the larger outlet of the Shuenk turbo to the OEM hotside charge pipe.
With all of the parts on hand, installation will begin shortly.