Subaru WRX STI
Charging Spec-C’razy’
A simple difference between the normal GDB chasis Subaru Impreza STI and the Spec-C variance would be the immense lightening and improved handling between the STI and Spec-C. Though both variants share the same engine output, handling, the AWD system and other OEM parts, the difference lies with the weight shaving process which benefits the response and the handling of the car.
The Spec-C forgoes some comfort from the STI for the sake of performance. Most of the sound muffling materials weren’t installed at all from production, so you can imagine the deafening rumble from the engine and exhaust that you would experience in this ride. Even the glass panels are thinner and lighter. With more priority placed in the overall weight department, it would be safe to say that only a true-blooded petrol head will consider investing in a Spec-C. Not to say that the lack of comfort prevents it from being a daily road driven car, in fact, this Spec-C would serve such a purpose well with the added choice sending skirts flying as you zip past the ladies. Imagine this Spec-C, with tuning in both areas of responsiveness and handling, what would you get? The answer: an adrenalin pumped drive every time you throttle it and going in and out of corners. I bet my bottom that the ride’s rumbling power will send your adrenaline flowing when you enter an empty straight road. If you had your way, you’d zoom down the road like a low flying missile.
I was given the luxury of a taxi-ride (ok then we italicize it) during our photo shoot to review this Spec-C. This Spec-C was tuned by the hands of Mr. C.F Lo from Speed Syndicate himself and he was kind enough to humor me with his wicked driving style aka as the crazy taxi driver. His intention was to intrigue me with the Spec-C’s response and handling after tuning. So off we went to the back lane of his shop, a short 300m sprint. He switched the turbine boost level to 1.3bar at full spool, throttled down, and shifted the gears up. The dizzying G’s pushed me back into the seat every time a full spool was reached. As we approached the T-junction and end of the road, Mr. Lo performed his braking, gear dropping and turn-in technique at lightning speed just before we ran out of tarmac. I would’ve been screaming like a little girl if I wasn’t a petrol head myself. I kept my cool and held on to my manly instincts, but told myself “WOW, this is one heck of a ride!”. Well, a stock standard STI may fail to impress me, even a non-tuned Spec-C as well, but this particular unit was well-tuned. Forget the horses, this baby runs on friggin bulls!
Weight plays a role on the Spec-C’s performance, but I won’t go into lenghty detail on this. The engine is pretty much left alone, sporting the same STI version-ed boxer EJ20 flat-four setup with a gearbox oil cooler for the 6-speed tranny. It is also has OEM golden Brembo’s from the factory. As Mr. C.F Lo puts it, a modified street car can have high horsepower and torque, but what is power and torque to the driver without reliability and drivability for a daily-driven street car?
To begin with, the responsiveness is enhanced with a set of Trust Titanium mufflers and customized 3in piping from the downpipe all the way to the muffler. This relieves some of the restriction commonly found on OEM’s piping, especially from turbo charged cars. This smooth exhaust gas exit allows for faster spooling from the turbo, enabling the car to produce more power in a shorter time. At first glance, the engine bay sports an obvious blue-ish PS-PowerSport blow-off valve that replaced the factory unit for the increased charged air – something that the factory units lacked when the boost level is dialed up.
A 2.5in Apex’i Power Intake open pod style air cleaner replaced the restrictive factory unit while a PS-PowerSport Battery Power Stabler provides the little enhancements that are not always necessarily associated with performance, but generally contributes towards the overall healthiness of the engine.
The increased boost level is regulated and controlled by a PS-PowerSport Digital Turbo Booster-II (DTB) with a Lo and Hi settings. The small black device is mounted under the dashboard while the booster control valve device is mounted in the engine bay, located close to the turbo to minimize turbine spool-up lagging. This little device does more than merely regulating boost level, it also senses intake pressure in the intake manifold with advanced closed-loop readings and automatically regulates it to allow the waste-gate/actuator to close much longer.
Ignition sparks were further enhanced with a PS-PowerSport Brisk Spark Energizer II that when attached to the firing coil, provides a thorough and efficient ignition spark. This in turn provides for a better overall combustion. Whenever there’s an increase in air pressure volume and higher optimum ignition for combustion, there is surely an increase of fuel to compensate. To deal with this, a PS-PowerSport Air Fuel Enhancer II (AFE-II) is wired to the factory ECU, tuned to supply sufficient fueling to avoid any un-wanted and damaging detonation. Aside from pre-set tuning, additional supplementary of LOW, MID and HIGH settings can be adjusted by the driver on the fly. With all the choking G’s and running electronics during a hard drive, a fuel pump powered by the car electricity might not work perfectly. This normally spells D-I-S-A-S-T-E-R, potentially creating fuel starvation for the engine. To prevent this from happening, a PS-PowerSport Fuel Flow Stabilizer ensures a constant and reliable flow of electricity to the fuel pump.
Adding such a load to the engine and fuelling require some sort of monitoring for the air/fuel ratio process; a tool that most tuning-heads regard as the defensive line before breaking their precious ride’s heart. In this case, it comes in the form of a PS-PowerSport Air/Fuel Mixture Analyzer. The device reports the air/fuel reading and shows whether is too rich or too lean. With this warning, the driver can concentrate on the road and fully enjoy the drive. The monitoring system also include Subaru STI Genome Gauges, which is OEM by Defi. A complete the list of gauges with Oil Pressure, Oil Temp, Water Temp and Boost gauge.
Turbo cool-down is done via an Apex’i black edition pen-style turbo timer and a black edition Apex’i RSM to provide the clocking of speed and 0-400m sprints. Don’t be fooled when it comes to the car’s ferocity when I say that the cabin is pretty much stock and standard. Like the cute female librarian with a conservative front, you will be gladly surprised to see what this dark horse has to offer. Upon closer inspection, you’ll find that it’s anything but stock. Tucked away and seemingly hidden are the little gadgets and gauges, which give the cabin the feel of a jet fighter cockpit. The driver obviously feels like a jet fighter pilot going for a dogfight as soon as the engine is ignited and the driver is strapped to the seats.
The engine bay is adorned with SARD silicon hoses which include a set of hardened silicone hoses for the radiator. An Apex’i radiator cap ensures that hot pressure is concealed in the radiator and the additional air-to-air cooling channeled to the factory radiator is directed by an alluminium Greddy panel.
Truth be told, such a setup is nothing compared to monster tuned rides with an entire directory of upgrade of hardware with a long go-fast-bits list, but the response and handling is what matters for this Spec-C with daily drivability in mind. Improvements to the handling is doubled up with a set of Cusco Zero-2 height adjustable coilovers with a 5-stage adjustment for the dampening force and Cusco pillow ball mount. This Spec-C can do wonders at corners, thanks to a pair of Cusco strut tower bar in the engine bay and the rear boot to limit body roll and the lowering of the overall ride height for much more stability.
Every tuner knows the rules in the books. And like all rules, items like sticky rubbers apply to this raging bull. Wrapped around the Volk Racing CE-28 17in are Goodyear Eagle RS Sport 235/45 rubbers at all four corners. RAYS forged Dura wheel nuts bolt the wheels nicely, giving the wheel’s look with some contrast. Stopping power is provided by Brembo calipers that give the braking bites to APP rotors up front and standard rotor at the rear. To add more reliability to the braking power, APP steel-braided hoses are used to eliminate the spongy feeling and inconsistency. To top it off, Endless 500˚c pads replace the OEMs, reflecting the seriousness of this Spec-C’s owner when it comes to the handling and breaking department. Simplicity applies to the exterior, sporting only a rear Kansai diffuser for the down force effects, leaving the rest of the exterior in stock and standard form.
Alpine DVA-9860E headunit cum DVD player and Pioneer AVX-7650 LCD display is the only simple but sufficient piece of ICE that entertains the owner during a long haul drive. A GPS armed alarm system protects this Spec-C from any un-wanted hands trying to hijack this Spec-C.
Combined with the tuned setup, the Spec-C’s natural weight reduction purpose built, the car’s handling and braking, this Spec-C is at top of its game. There is nothing magical here, just simple bolt-on performance and tons of driving fun with the upgraded braking and handling. This is what I call a perfect daily driving machine. The future path for this raging Spec-C includes a bigger and more responsive turbine and the accompanied hardware. That being said, this requires significant planning and budgeting. So keep an eye out for this Spec-C, as we at Pro-Tuners will be locking our radar onto this Spec-C for future upgrades and tunings.
TUNE-SPEC
Subaru Impreza STI Spec-C, GDB
OUTPUT
320whp at 1.3 bar
ENGINE HARDWARE
EJ20, 16v, Turbo, Flat-4 Boxer
ENGINE ACCESORIES
PS-PowerSport Digital Turbo Booster II, PS-PowerSport Fuel Flow Stabilizer, PS-PowerSport Air Fuel Enhancer II, PS-PowerSport Brisks Sparks Energizer II, PS-PowerSport Battery Power Stabler, Apex’i 2.5in Power Intake open-pod filter, Apex’i Radiator Cap, 3in Straight Flow from downpipe, Trust Titanium Muffler, Greddy Alum Radiator Cooling Panel, SARD vacuum hoses, SARD Hardened Silicon Radiator Hose
DRIVETRAIN HARDWARE
Standard 6-speed M/T
BRAKES AND SUSPENSION
CUSCO Zero-2 Adjustable Coilovers with pillow ball mount, APP Front Rotor, APP Braided Hoses, Endless 500°C Brake Pads, CUSCO Front/Rear Strut Tower Bars
WHEELS AND TYRE
17in Volk Racing CE28 rims 8.5jj, wrapped with Goodyear Eagle RS Sport 235/45 tyres, RAYS Forged Dura Wheels Nuts
GADGETRY
PS-PowerSport Air/Fuel Mixture Analyzer, Apex’i Black Edition RSM and Pen-Style Countdown Timer, STI Genome Oil Pressure, Oil Temp, Water Temp and Boost Gauge with Controller
ICE
Alpine DVA-9860E Headunit, Pioneer AVX-7650 LCD Monitor
GARAGE
Speed Syndicate Sdn. Bhd.
TUNER
Mr. C.F Lo
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