Full-Race Twin EFR Turbo Kit
Part 4: The Heart of FReak-O-Boost
Ford's F-150 EcoBoost Turbos are manufactured by BorgWarner Turbo Systems. These potent K03 turbocharges have long proven to provide reliable boost for automakers such as Porsche, Audi, VW, Volvo, Mazda, Mini, Ford, Mercedes, BMW and more. One unique aspect of the F-150's K03 is their forged-milled compressor wheel (aka forged billet) at 51mm OD for a max combined flow rate of ~50lb/min at full tilt. These OEM K03 turbos work well for daily duty, and respond nicely to bolt-on mods, but they won't allow this truck to really stretch it's legs with our lofty future goals.
While the stock K03 turbos work well for daily duty, they won't allow this truck to really stretch it's legs. In order to make 500+hp the rate of airflow required is at least 56-60lb/min. This means we can upgrade the twin turbos OR we can remove the twins and convert to a single turbo. Working with BorgWarner and Ford on the engine analysis, we all agreed the most important characteristic for a high performance truck's turbo system is instant spool and response, with strong low-end/mid-range torque.
In order to make beyond 500+hp the rate of airflow required is at least 60+lb/min for low boost and a target of 80lb/min at full boost. Working with BorgWarner and Ford on the engine analysis, the LMP and Daytona Prototype racing engine teams began testing with twin EFR6258 turbos on Roush Yates "Libra" EcoBoost engines - and the results were outstanding. Everyone on the team agreed that the most important characteristic for a high performance truck's turbo system is excellent spool and response, with strong low-end/mid-range torque - and the EFR6258s delivered.
BorgWarner's EFR Series of Turbocharger is the perfect match with the F-150 EcoBoost with features including for their featureset and performance:
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 performance targets/goals of the truck were agreed upon and the installation had to be a 100% bolt-on, that could be installed over a long weekend in a home garage. Full-Race didn't want to limit ourselves in turbo size - we needed to make sure that maximum versatility would be built into the system design and that any future EFR's could fit this existing footprint with minimal changes. Would someone try and run 10 second 1/4 mile with an F-150 EcoBoost in the future? Maybe! We worked hard to ensure the same F-150 single turbo kit would support the smaller EFR6258s up to the largest Indycar EFR7163 (max 1100 HP) turbos.
Time to do some work:
The first part of the single turbo conversion is also the most time consuming: removing the stock turbos. These twin K03's 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). We will go into more detailed instructions in our install guide, but for now it's important to start with removing the front wheels and inner fender liners. This only takes 10 minutes to do 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 6.2L. If you're use to working on twin turbo engines shoehorned in tiny Japanese cars - do not fret! The 3.5L V6 Bcoboost is not nearly as crammed as the Nissan 300ZX or GTR - there is just enough room to work with. Also, the handling improvement for the V6 trucks is 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.
Knowledge is power, and knowing how much boost we're running + turbocharger speed is crucial. Instead of a normal old boost gauge, we wanted more data out of our EFR turbo and turned to Road Rage Gages for their "SBT". Road Rage Gages SBT display monitors Turbo Shaft Speed (Krpm), Temp (F or C of transmission or EGT or other) and Boost (psi or kpa). It is a direct plug-in to the EFR's turbo speed sensor, we plan to use the temp readings for Automatic Transmission Fluid temp.
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.The log manifolds are comprised of high nickel "ni-resist" casting to maximize strength and heat containment for a long crack-free life. The log manifold outlet diamater is very small at only 29.5mm/1.18". The K03 turbos are 34mm diameter inlets and the gaskets are 35mm diameter, but with well over 12mm / 0.500" of porting area, there is some room for porting and slightly increased/improved flow. However, the outlet is still quite small for supporting higher power levels, even after porting, and the larger diameter EFR turbos physically can not fit where the tiny K03's originally resided. This goal lead us to focusing our efforts towards replacing these log manifolds with an efficient 3->1 merge collector long runner tubular turbo manifold
Engine Management: Heat Protection, Battery and ECU
Whenever there is an increase in horsepower, there is going to be an increase in engine bay heat. In the case of this turbo kit, the top mounted turbo and downpipe will give off heat. The next step in the process is to protect the PCM (engine computer) harness, respective wiring connectors and plug. Located on the firewall of the F-150, the standard EcoBoost computer is manufactured by Bosch for high performance turbocharged direct injection engines. Water tight and vibration proof this unit has fast processor speed and with SCT Flash software accessing the tables there is no reason to upgrade to a standalone aftermarket ecu for a street driven F150
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.
Next we have to protect the coolant lines. First remove the OEM coolant hose spacers (we have no idea why they are used at all) then extend the passenger side's 3/4" / 19mm silicone hose with barb fittings to extend the lines along the fender. The lines are then covered in orange "firesleeve" for additional heat resistance.
Now it's time to plumb the engine and turbos. We carefully removed and plugged the unused water and oil ports on the passenger side, then prep the new hoses, lines and fittings
The factory computer is equipped with (2) wideband O2 sensors and (2) post-cat sensors. Each wideband must monitor its own bank of cylinders. We start by installing the manifolds, then the turbos, then the downpipe and intercooler charge pipes.
Lastly, we have give all of our mandrel-bent piping a once-over before the durable black powder coating is applied. Everything fit perfectly and we were ready for final assembly and boost leak test. Note: The electronic blow off valve on our 2013 was disabled, and we ran the mechanical BOV on the EFR turbo (similar configuration to 2011-2012 F-150).
Finally we have to plug-in the EFR boost control solenoid valve (BCSV). Thankfully it's identical to the Ford valve (both valves are identically made by Pierburg) so it's literally plug-and-play.
It took many late nights to get to this point, but the deadline was here and we were on time. After giving everything a once-over it was time to start the FReak-o-Boost. On the first keystroke she fired perfectly as if nothing had ever changed:
At this point we had the engine bay completed and running perfectly. Everything had the utmost care and attention so that nothing would have to be redone and we could make it to the show on time. The effort was successful and the welds were still warm when our transporter showed up (literally!). The truck was now in route to Las Vegas for SEMA 2012.
As soon as the truck was dropped off, there was an instant crowd. Full-Race has been attending SEMA for the 11 years. We've brought many cars over that time and this truck definitely set the bar high for future projects based off the attention received before the show even started.
Tuesday morning was the 1st day of SEMA, and the truck would debut with 4X Indy 500 winner Dario Franchitti along our truck in the BorgWarner booth.
The FReakoBoost was picked by Hot Rod Magazine as one of the Top 10 Trucks at SEMA.