Nerd’s Eye View: SEMA 2014 Part II


The tricky part of the new 2.3L Ecoboost engine is the exhaust port shape coming off the cylinder head. The engine in stock form comes with a twin-scroll turbocharger. The engine also has the exhaust manifold integrated into the head of the engine. The resulting exhaust port shape is quite unique. The unique shape means there is no simple rectangular flange shape to work with. Full-Race was able to fabricate this adapter to match the unique port shape. Let me tell you, that’s not an easy feat, so much props to Full-Race for that.
Perhaps one of the most interesting products in all the SEMA show is this new turbine housing from Borg Warner for the EFR series. Yup, those are two wastegate actuators on it. In aftermarket speak, the turbine housing has a quick-spool valve integrated for very quick spool-up at low engine speeds. One actuator is for the internal wastegate and the other for the quick-spool valve. In OEM speak, this would be considered a variable A/R turbine housing. The old FC generation RX-7 and more recent (2007) Acura RDX with the 2.3L 4-banger have somewhat similar variable A/R turbine housing designs.
Here you can see the flapper valve that closes off one half of the twin-scroll turbine housing effectively reducing the A/R of the turbine housing by half. With all the exhaust gas going through half the turbine housing, the turbo is spooled up much more quickly at low engine speeds. As the engine speed and exhaust flow comes up, the valve opens allowing more flow though the turbine with reduced back pressure for greater power.
The EFR lineup is getting a host of performance improvements. I think the most important one is the aluminum center housing in place of the old cast iron piece. By switching to aluminum, the weight of the turbo is greatly reduced. From a packaging standpoint, the new compressor housing with the 90 degree outlet can make a fabricator’s job much easier.
The company Road Rage Gages makes this nifty display to work with the optional turbo speed sensor for the EFR turbos. It also shows boost and temperature of a thermocouple which you can use to keep tabs on exhaust temperature. To show it reading boost pressure, this little hand pump commonly seen on the arm bands for measuring blood pressure was used. FYI, I maxed it out at 23psi at which point I think air was leaking past the hoses of the hand pump setup.

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