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2013 Scion FR–S - Power Pages

The dyno doesn't lie.

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Dynamometer: SR Motorcar Dynojet

Baseline

Pros

The masterminds behind the Scion FR-S developed a new vehicle platform that not only handled well, but also catered to performance enthusiasts with its lightweight chassis and rear-wheel-drive platform. Taking inspiration from three Toyota models: the Sports 800, 2000 GT, and the AE86 Hachiroku, Toyota brought back the return of its horizontally opposed engine that was first produced back in 1965 in the 0.8L 2U (45 bhp at 5,400 rpm) Yota-Hachi. The 4U-GSE was engineered with a 12.5:1 compression ratio engine. The direct injection D-4S technology donated from Toyota to Subaru boxer engines uses eight injectors. Four injectors fire separately for direct injection and the remaining are used for port injection-an intricate fuel delivery system that enables the engine to produce 200 hp and 151 lb-ft of torque. It's been less than four months since its U.S. debut and already tuner shops have begun tearing into the engine, including fabricating custom turbo kits, which have been rumored to push the horsepower level to the tune of 500 whp.

Cons

While turbocharging is the easiest way to make horsepower with the FR-S, we're still not convinced on the adverse affects of boosting the 4U-GSE engine and how it would hold up to the forced-induction punishment with the engine still in OE form until long-term testing has commenced. For those who are looking for a marginable increase in power but focus on maintaining vehicle/engine reliability, we found a number of bolt-on parts within the short time span the FR-S has been available that were readily on the market.

Notes

Prior to performing a baseline run the vehicle was already equipped with an HKS Hi-Power Spec-L exhaust, yet still retained usage of the factory intake filter/system. We should note that the vehicle was also equipped with larger-than-factory-sized 18-inch Enkei wheels. The FR-S spun the rollers and registered in at 161.4 hp and 132.7 lb-ft of torque.

Cusco Earth Grounding Kit

Parts

Grounding kit

Tools

10, 12, and 14mm sockets; 10, 12, and 14mm open-end wrenches; ratchet; extension; and screwdriver

Installation time

40 minutes

Pros

The Cusco Earth Grounding Kit is made from ultralow resistance wiring and thick vinyl composite shielding for protection from heat and elements, enabling improved electrical current distribution throughout the engine for improved idle and driveability. We liked the fact that each wire is individually labeled with mounting points for optimal performance.

Cons

All cars regardless of make or model, including the new FR-S, suffer from electrical resistance/impedance, an enemy of your car's electrical equipment and its ability to properly perform. Your spark plugs, lights, fans, stereo and air conditioner are interconnected from an elaborate electrical network that includes fuses, relays, and high-quality electrical cabling. These components all share a common ground; however, most OEM grounding systems consist of just a few skinny braided cables. Good electrical performance requires a proper grounding system that's prepared to take a lot of current with minimal resistance.

Notes

Dyno testing the Cusco Ground kit revealed a peak gain of 2.3 hp and 2.2 lb-ft torque over our baseline numbers. The grounding kit increased both horsepower and torque throughout the powerband; the FR-S saw a consistent gain of 3 hp and 4 lb-ft torque from 4,500 rpm to 4,900 rpm.

Cusco Ignition Capacitor with Optional Harness

Parts

Cusco Ignition unit, zip ties, double-sided tape, mounting bracket, nuts and bolts, and instructions

Tools

8, 10, and 12mm sockets; 8, 10, and 12mm open-end wrenches; ratchet; extension; screwdriver; wires; and grounding connectors

Installation time

60 minutes

Pros

The Cusco Ignition Capacitor improves engine response from low to high rpm range by supplying the ignition coil with stable voltage for increased spark output. Cusco representatives state their ignition capacitor unit allows better acceleration response, a decrease in unburnt fuel, smoother engine revving, more responsive engine startup, and improved torque. The capacitor system reduces voltage resistance while maximizing efficiency both to and from the battery, and is ideal for vehicles equipped with additional aftermarket electronic components.

Cons

The Cusco Ignition system is a plug-and-play affair with the use of the optional vehicle specific harness. Unfortunately, the harness costs more than the unit, which poses a concern for those who are on a tight budget. Cusco reps state that the ignition system was designed to alternatively splice into the existing engine harness to cut down on costs but should not be attempted by novice electricians.

Notes

We experienced quite a scare when our engine began misfiring along with an engine check light when attempting to fire up the car for the first time. A bad connection using the optional jumper harness was found to be the culprit before it was properly addressed. After troubleshooting for over an hour, we came to the realization that using an OBD-II scan tool failed to reset/erase the engine error codes. To remedy the problem, we followed the Japanese shop manual's directions and drove the car for more than 10 minutes on the street before the ECU automatically reset. The Cusco Ignition Capacitor System increased both horsepower and torque across the board, with peak gains of 2.5 hp and 3.9 lb-ft of torque over baseline. The FR-S recorded gains at 2,500 rpm with a gain of 2.5 hp and 5 lb-ft of torque, and the largest taking place at 7,490 rpm to redline with a gain of 6 hp and 5 lb-ft of torque.

Cusco Overbored Throttle Body

Parts

Throttle body

Tools

10, 12, and 14mm sockets; 10, 12, and 14mm open-end wrenches; ratchet; extension; Vise-Grip wrench; hose clamps; coolant pinch tools; and screwdriver

Installation time

120 minutes

Pros

One popular method of improving engine performance is to increase airflow, through the use of a low-restriction air cleaner and an overbored throttle body. The Cusco throttle body is a direct bolt-on, plug-and-play unit for the 2.0L 4U-GSE powerplant. Offering OEM fitment and compatibility with the factory ECU, the throttle body is designed to improve the air intake efficiency as well as acceleration response. The 2mm overbored throttle body offers increased volumetric air intake efficiency, which delivers more torque and power output.

Cons

Although no factory core exchange is required upon purchase, this throttle body is anything but cheap. Cusco reps state that the inflated cost is due to sourcing and modifying a throttle body purchased directly from Subaru. Using an OEM unit was the logical solution for Cusco, as it offers both factory quality and reliability.

Notes

When installing the new throttle body, take precaution in removing the factory unit and carefully set it aside to prevent any damage. We recommend replacing the factory intake gasket to ensure a leak-free seal. Use a pinch tool to clamp off the coolant hoses during the throttle body swap to minimize unnecessary bleed-off. The FR-S picked up a gain of 4 hp and 3 lb-ft torque over our previous run at 4,600 rpm. The dyno revealed the largest gains of 5 hp and 4 lb-ft of torque at 6,600 rpm.

Conclusion

Testing our FR-S with three basic bolt-on products delivered a gain of 6.8 hp and 6.4 lb-ft torque over our baseline run. However, beyond just peak numbers you'll see a substantial increase in power output throughout the entire powerband. The 4U-GSE powerplant responded well to our modifications, and acceleration was noticeably improved on the street. Modifications completed to this point only served to increase our engine's efficiency-meaning we'll see increased reliability and fuel efficiency from our new FR-S, alongside more power . . . as long as we can keep from driving at full throttle! Stay tuned in our upcoming issue as we attempt to tackle the 4U-GSE ECU with an aftermarket engine management system for more horsepower.


Conclusion HP +HP TQ +TQ
Baseline 161.4 132.7
Cusco Earth Grounding Kit 163.7 2.3 134.9 2.2
Cusco Ignition Capacitor 165.5 1.8 135.2 0.3
Cusco Throttle Body 168.2 2.7 139.1 3.9
Final 168.2 6.8 139.1 6.4

Bankroll
Cusco Earth Grounding Kit $200
Cusco Ignition Capacitor $214
Optional Ignition Wire Harness $440
Cusco Throttle Body $1,707
Total $2,561

HOTBOX
Cusco USA
16631 Gemini Lane
Huntington Beach
CA  92647
714-907-0033
http://www.cuscousainc.com
SR Motorcars
310-516-1003
www.srmotorcars.com
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