As enthusiasts we’re all looking for that one Holy Grail modification. The single mod that changes the game for our car and sets the stage for how we measure all future modifications. This is especially true when we’re dealing with a car that’s been significantly changed or with a new engine platform. Whether it’s a new engine, new chassis, or both, when there’s a big change to the Mustang, the book of what works gets rewritten for the new model.
Project 5-Liter-Eater, our 2015 Mustang EcoBoost, is a prime example of the above. We know there’s plenty of potential lurking within the 2.3-liter 4-banger, we just have to find ways to unlock it. One of the areas we’ve heard rumblings about since these cars hit the streets is the electronic blow off valve. Ford not only constructed this valve from plastic, but also went with an electronic computer control for its operation, rather than the traditional mechanical vacuum line. There are several issues with the OEM BOV, fortunately the team over at Turbosmart has recently released a solution for EcoBoost Mustang owners to remedy their blow off valve blues.
The OEM computer is adaptive, even when tuned, it may still want to go back to the original parameters. Controlling boost pressure through the factory BOV is one way to do that. -Marty Staggs, Turbosmart
We also have concerns about the plastic construction of the OEM BOV. We wonder just how much boost this component can withstand before we literally blow it apart. The valve was likely made from plastic to save money and weight on the car. This valve is so weak, we can actuate it with the press of a pinky finger when removed from the charge pipe, leaving us to wonder just how much boost is being left on the table. That being said, with us already seeing 25 psi on the factory boost gauge we’re pretty sure the OEM design isn’t robust enough for our intentions.
Turbosmart has been making blow off valve upgrades for direct OEM replacement, performance oriented models for aftermarket turbo systems, and more aggressive upgrades for several years.
For our EcoBoost, the Kompact blow off valve, part number TS-0203-1081 , is a direct replacement for the OEM valve although some minor modification is required (more on that in a minute). The Kompact BOV is constructed from billet aluminum, making it more robust than the OEM BOV. It is mechanically actuated via a vacuum line, like the traditional BOVs.
The Kompact BOV is also what’s known as a 50-percent or dual port valve. The stock BOV vents all of the boost back to the air inlet, whereas the Kompact vents 50-percent of that boost back into atmosphere giving the satisfying swoosh sound commonly associated with high output turbo engines. “Not only does this valve give enthusiasts the sound they’re looking for, it also will grow with the application allowing owners to make use of this valve in applications making up to 500 hp,” says Staggs.
Because the Kompact BOV is a direct fit in terms of OEM replacement, the install will take most enthusiasts 30 minutes or less to complete. Turbosmart provides a resistor that connects to the factory BOV harness. This resistor sends the proper signal back to the ECM, leaving it none the wiser that the electronic BOV has been replaced. “We designed this part so that most typical enthusiasts can replace it in their garage in under an hour, and there’s no special tuning or adjustments required -just bolt it on and go” says Staggs.
Also included with the Kompact BOV is a vacuum line and a billet aluminum adapter. This adapter goes into the intake manifold at the MAP sensor port, allowing the MAP sensor to plug into the new port. The adapter has two threaded NPT ports, and a nipple is included for the supplied vacuum hose, as well as a plug for the second port which could be fitted to a boost gauge, data logger, or other device that needs a vacuum source.
We bolted on the Turbosmart Kompact valve in about 15 minutes with the car strapped to the Dyno at London Chassis Dyno (LCD). We previously baselined the car at 291.8 hp and 339.9 lb-ft of torque with our only modification currently on the car being a SCT 93 octane tune that was included with our X4.
Spinning the rollers at LCD, we did a double take as LCD owner Chad Epperson shouted the numbers to us as the dyno coasted down. Our car’s boost gauge was reading 26-27 psi, and given what Epperson was yelling, we decided an immediate second pull was in order.
With the car pulling strong on the dyno again, our second test was completed, and the results were confirmed. We had only gained 7.3 hp at the wheels, however the real results were showing up in the torque, 44.3 lb-ft more to the rear tires, giving us a total of 384.2 lb-ft of torque at the rear tires, and 299.1 hp. Both dyno pulls had been within 0.1 hp and 0.1 lb-ft of each other, and the dyno was recently calibrated. Furthermore, the temperature was in the high 50s outside, our IAT was 63-degrees at the air intake, and the dyno weather correction factor was 1.006, making our conditions ideal for testing.
Peak power seldom tells the whole story, and we’re finding that’s very true with our Mustang EcoBoost. Comparing our two dyno graphs, we can see that the blow off valve made more horsepower and torque throughout the RPM band of our test window, which began at 2,500 rpm and ended at 5,800 rpm. Using the dyno software we can see that the engine made an average of 293.1 lb-ft for the entire pull with a tune alone, while it made an average of 318.2 lb-ft after swapping the BOV. Horsepower averages were also improved as our Mustang produced an average of 257.1 hp on tune alone, and produced a 270.2 hp average after swapping the BOV; for an average gain under the curve of 13.1 hp and 25.1 lb-ft.
Since the Kompact BOV is mechanically controlled, instead of electronically, it allows the turbo to build boost more rapidly, getting the turbo to high boost pressure fast and allowing it to stay there.
We now have torque that is beating what we’ve tested a stock Mustang GT at (369.7 lb-ft). With only two modifications to our EcoBoost, it also exceeds what many modified Mustang GTs are seeing with a tune and some similarly priced bolt-on parts.
Staggs explains the gains like this. “Since the Kompact BOV is mechanically controlled, instead of electronically, it allows the turbo to build boost more rapidly, getting the turbo to high boost pressure fast and allowing it to stay there.” According to Staggs this lets the engine make more horsepower and much higher torque since there’s more boost coming in sooner and staying there until you lift or reach the engine’s peak power -we’re seeing more of the engine’s true potential.
With V8 level torque numbers now coming out of our project car, we’re one step closer to it fully earning the name 5-Liter-Eater. Our Turbosmart Kompact BOV will undoubtedly help us as we continue to modify the car, and make more changes.