Scion FR-S Edelbrock Supercharger Review
BOOST AND ETHANOL E85 SAVES THIS AUTOMATIC SCION FR-S
In a world where cars steer, brake, and even park themselves, the Scion FR-S begs to be tossed at apexes with reckless abandon…and it won’t buzz at you if you drift out of your lane. The balance and styling of the car are worldclass, but be ready for a chorus of crickets when you jump on the gas.
Everett, Washington’s Jason Helmick doesn’t care for crickets and admits his Hot Lava Red ’15 FR-S was more doomed than most, because it sports a power-robbing, soulstealing automatic transmission. “Everybody says these cars are a little underpowered when stock, like 160 to 170 hp to the wheels,” Jason says. “I drove an automatic and a manual, and I liked the automatic better. I preferred the paddle shift. I just felt the shift response was a lot better. But I have to say it’s pretty much a dog on the highway. There is no torque, and unless it’s wound up in Third gear, the car just doesn’t have enough balls to pass another car. I have to work up to it.”
Jason admits he had zero plans to build the FR-S; it was just going to be a daily driver. “But a friend of mine wrecked his BRZ,” he explains. “It was supercharged…i saw an opportunity and jumped at it. From there, it just grew organically. Before long, I was going to shows. The car’s won the last four shows it’s been in.” The supercharger was Edelbrock’s E-force, which features an Eaton TVS 1320 roots-style blower. Jason collected every last piece of the kit and trekked south about 55 miles to the Drift-office in Auburn. Drift-office is the region’s go-to tuning shop for all things FA20. The shop installed the first production Edelbrock unit and has bolted on no less than 25 others since 2016. The crew is quick to point out that Edelbrock has really done its homework from a tuning standpoint, providing a healthy base tune that passes CARB certification, but the shop prefers dropping its own tune on the kit’s Ecutek tuning software.
MASS AIR MAYHEM
Drift-office’s Bill Lee says one of the good things about the design, and Edelbrock’s approach in general, is knowing the challenges installers/tuners face. “The mass airflow (MAF) sensor housing is a perfect example of this,” Bill says. “Since the kit replaces the intake completely, they had to come up with a very smart design to fit the housing in a very compact space without sacrificing how it flows. Flow around the sensor is key because any time you change those things, and if they’re not engineered properly, you’ll get turbulence or poor flow, which causes big tuning headaches.”
“Edelbrock has done very nicely designing the cross sections in front of the sensor to straighten out the airflow and minimize any of those turbulence issues. Since the mass airflow sensor is so different from factory, we had to scale it optimally and tune it to produce the proper air/fuel ratios under boost.”
TUNING AN AUTOMATIC
Traditionally, automatics have been bears to tune, as they tend to kick down a gear on the dyno, whereas a manual can be run from low rpm to redline. “Jason’s car, because it’s an automatic,” Bill says, “had to be tuned with a specific focus on lugging at low rpm and keeping the engine from struggling for too long. So, we focused on the response and its transition into usable power. Beyond the obvious driveability issues, we were concerned the ECU would learn and equate that lugging with knock and eventually kill the performance by defaulting to limp mode. To avoid this scenario, we recommended E85, because we’re able to run more timing, which really opened the door to incredibly fast response and greatly helped with the overall performance of the car.”
Ease of installation is one of the Edelbrock kit’s strong suits.It is a simple remove-and-replace operation, as the supercharger and manifold are one piece. The manifold is an inverted design, with long runners that allow for maximum flow at high rpm, while retaining great daily driving characteristics. The unit’s integrated bypass valve is also commuter friendly, allowing little to no decrease in fuel economy.
Drift-office was quick to point to the proficient design of the Edelbrock mass airflow sensor as a key to the kit’s tunerfriendly personality. Its stable flow characteristics allow for tuning beyond the stock kit’s already impressive flash-and-go stock tune of around 240 whp.
Moto-east’s well-sorted, leading-edge flex fuel kit is the key to making E85 work in the real world. Ethanol E85 stations are scarce, so being able to switch to and from E85 on the fly is crucial. Drift-office praises the flex kit’s use of AN fittings, braided ethanol-compatible hose, and a fully plug-and-play ECU harness, all of which are tailor-made for the FA20 platform. The accuracy of the kit’s Zeitronix ECA (Ethanol Content Analyzer) sensor is critical, especially with returnless fuel systems like in the FA20. “You have to make sure that when it sees ethanol, that’s actually what’s in the rails,” says Bill, “to minimize the transition period where your performance will be a little bit off until the E85 is fully introduced.”