Full-Race Twin EFR Turbo Kit
Part 4: The Heart of FReak-O-Boost
BorgWarner Turbo Systems in Asheville, NC designs and manufactures high performance Turbos for Ford’s EcoBoost F150. BW’s K-series turbochargers have long proven themselves to generate dependable boost and great value for automakers such as Porsche, Audi, VW, Volvo, Mazda, Mini, Ford, Mercedes, GM, BMW and more. Ford’s Longitudinal EcoBoost 3.5L engines use BW’s latest generation KOCG turbine wheel aerodynamics with CFD-optimized housings. F150 turbos are conservatively detuned to have a max combined flow rate of ~50lb/min at full tilt. They work well for daily duty and respond nicely to bolt-on mods, but won’t allow this truck to really stretch it’s legs with our lofty future goals.
In order to generate a true 500+hp the airflow rate required is ~60-65lb/min. However we unanimously agreed the most important characteristics for a high performance V6 turbo system is early spool, strong boost response and abundant low-end/mid-range torque. Working with BorgWarner and Ford on the engine analysis, the groundwork was laid out for 2 uniquely different upgrade paths: A simple bolt-on turbo upgrade for 400-500hp OR a hardcore Twin-Turbo EFR kit for heavily modified ecoBoost V6 racing engines with 500-700+hp capability
In 2011, Roush Yates’ LMP and Daytona Prototype racing engine teams began testing with twin BorgWarner EFR turbos on their OEM-based “Libra” EcoBoost V6 engines (upgraded turbos, rods, pistons, fuel). 2013 brought outstanding race-day results: Colin Braun drove a Riley Technologies Daytona Prototype race car, powered by twin EFR6258 3.5-liter V6 Ford EcoBoost engine, to a new Daytona single-lap speed record of 222.971 mph (topping a 26-year-old speed record of 210.364 mph set by Bill Elliott in a Ford Thunderbird in qualifying for the 1987 Daytona 500). Braun and Michael Shank Racing also set new world speed records for 10 miles from a standing start (210.018 mph average) and 10 kilometers from a standing start (202.438 mph average). “This is a project we started probably two years ago,” said John Maddox, road racing program manager, Roush Yates Engines. “There has been a lot of hard work by a lot of people to get it to where it is today, but this EcoBoost engine is relevant, state-of-the-art production technology in racing, and it brings with it power and high efficiency in the same package. “When we broke the track speed record today, well, that’s big,” Maddox added. “But to come back and set two world speed records that have been around since 1979, well, that’s something to tell the grandkids some day.”
In order to live up to the name ‘FReak O Boost’ this truck was intended to be an extreme turbo-centric build that we’ll use as our development mule for years to come. While the simple bolt on F150 upgrade turbos are an easier install/tune we want to push the limits. Looking at RYE’s success, we decided to implement the same twin-EFR boosting strategy in our 2013 F150 Freak-O-Boost. BorgWarner’s EFR Series of Turbocharger remains the max-effort turbo of choice:
- Dual Row Ceramic Ball Bearings – lowest friction and fast spool/response, excellent durability
- Double seals on both turbine and compressor for extreme durability and resistance to any oil seepage
- Watercooled center section continues removing heat from the turbo after the engine is shut off (even when the water pump is not turning)
- Built-in oil control orifice – (aka oil restrictor) **No restrictor can be used with EFR turbos**
- Integrates seamlessly to the stock engine computer: The EFR boost control is integrated into the compressor housing using an identical electrical plug as the factory F-150 boost control
- Gamma-Ti turbine wheel: low inertia for immediate boost response
- Optional Speed Sensor
- Integrated high-flow wastegate is a perfect fit to this application
- Forged-Milled Wheel (FMW) extended tip compressor wheel
- Integrated mechanical BOV (like the 2011-2012 F150 EcoBoost). All 2013-2014 and 2015+ models use an electric BOV, which we disable on our truck in favor of the mechanical valves only.
The first part of the turbo upgrade is also the most time consuming: removing the stock turbos. These twin K0 turbos are tucked up by the frame rails with “not-quick-release” fittings. Using your factory service manual here saves a ton of time if you’re not experienced with the order of each step (it’s important – buy the manual if you’re going to do the wrenching). Starting by removal of the front wheels and inner fender liners (it only takes 10 minutes) and the entire side of the engine becomes easy to access. Removing the coolant and oil lines then allows you to remove the hardware and then extract the turbos.
The F-150 EcoBoost’s have roomy engines bays since the same bay is also large enough to fit the giant 6.2L V8. If you’re use to working on twin turbo engines shoehorned in tiny Japanese cars – do not fret! The 3.5L V6 Ecoboost is not nearly as crammed as the Nissan 300ZX or GT-R – there is just enough room to work with. Also, there is a handling improvement for the V6 trucks due to reduced weight on the front end. The center of gravity for the truck is lower and further back than the V8 F-150, thus improving overall handling.
F-150 EcoBoost Manifolds
Ford worked hard to design and validate the cast exhaust manifold on the longitudinal 3.5L EcoBoost for a BorgWarner K03 turbo (34mm inlet). Despite the log manifold design, it generates very early twin turbo spool and strong low end torque. These log manifolds are comprised of high nickel “ni-resist” casting to maximize strength and heat containment for a long crack-free life. Due to “core shift” in the casting process, the log manifold outlet diameter is small at only 29.5mm/1.18″. The K0 turbos inlet diameter is 34mm and the gaskets are 35mm diameter. For any applications targeting high power and GT upgrade turbos, it is worthwhile to consider porting out the manifold to match the 34mm turbo opening. The larger diameter EFR turbos physically can not fit where the OEM KO’s originally resided. This goal lead us to focusing our efforts towards replacing these log manifolds with highly efficient 3->1 merge collector tubular “equal length” turbo manifold.
Engine Management: Heat Protection, Battery and ECU
The next step is to protect the wiring harness using gold heat resistant foil and then external aluminum heatshields. This self adhesive “gold foil tape” works to reduce temps by over 800F in just 3mm air gap. We use this for all turbo kits that have a wiring harness near the manifold or turbo. We carefully cut the tape into 1″ strips and wrap it around the harness everywhere there is heat or an exhaust manifold nearby.
Ford also recognized our project by presenting us their “Project Excellence Award”