After the winning the 2020 and 2021 SCCA Florida Regional Championship, I decided to retire, for now, from the road racing competition. So, I sold my 2005 Subaru Impreza WRX STI, my 5th built racing car. This race car was finished in WR Blue with Rally Racing inspired graphics.
This car was powered by an EJ turbocharged 2.5-liter flat-four that was modified with bolt-on such as: Blouch Dominator 3.0 XTR turbocharger, a Perrin front mount intercooler and Perrin piping. Also, an aftermarket Grimmspeed boost controller, a ported factory intake manifold, a COBB Tuning AccessPort V3, high-performance Tomei exhaust components, Perrin ELH, up-pipe and Invidia downpipe. Some exterior upgrades were brake-cooling ducts integrated into the front bumper cover and Sabelt tow straps. Split-spoke 17×9” Enkei wheels are finished in silver and were mounted with 245/40 Hoosier R7 racing tires. Stopping power was provided by Brembo OEM calipers, Goodridge stainless-steel lines, and Hawk Performance DTC pads with Stoptech two-piece rotors in front, and the rear rotors were DBA 5000. Suspension modifications consisted of Tein coilovers, polished billet control arms, a Cusco stabilizer bar, and Perrin front and rear sway bars. The cockpit features a Sparco FIA racing seat with a Sabelt six-point harness, and driver conveniences include a helmet cooling fan and a Longacre drinking bottle. A full roll cage was installed and a FireSense fire extinguisher was mounted to the passenger floorboard.
Additional equipment included a camera mount, a Longacre kill switch and mirrors, Whiteline shifter bushings, and window nets. A Sparco steering wheel features a quick-release mechanism and frames factory instrumentation OEM STI 160-mph speedometer, a tachometer, and auxiliary gauges.
Additional bolts-on to the turbocharged EJ 2.5-liter flat-four were:
COBB Tuning short-ram intake, 4-bar manifold pressure sensor kit, Tial blow-off valve, Gates Racing water pump, timing belt, and 170-degree thermostat, Walbro 255 liter-per-hour fuel pump, and more.
Power was send to all four wheels through an OEM six-speed manual transaxle, and a carbon-fiber driveshaft. Additional modifications included Whiteline differential bushings, and a Beatrush pitch-stop mount. The exhaust system consists of a Perrin EQL header and an Invidia up-pipe and off-road downpipe fitted to a Tomei Extreme cat-back exhaust.
Here are a few reasons why I didn't keep the Subaru STI for another road racing season:
Weight: The STI is a relatively heavy vehicle, weighing in at around 3,300 lbs. This can make it less agile and responsive than lighter, more performance-focused vehicles on the track. Additionally, its weight resulted in higher tire and brake pad wear.
Suspension: Even with upgraded suspension, the STI's suspension is designed more for road handling and is not as capable of handling the high speeds and lateral loads encountered on a race track as other vehicles with more specialized suspension systems. It tended to understeer a lot.
Power delivery: The STI's power delivery may not be ideal for road racing, as it is geared more towards low-end torque and all-wheel drive traction rather than high-revving horsepower. This can make it less suited for high-speed straightaways and overtaking maneuvers on the track. Keeping up with BMWs and V8 cars was a challenge to maintain the same pace as them.
Poor engine quality: The EJ engine's build quality, including faulty parts, poor tolerances, and inadequate sealing, can result in premature wear, oil leaks, and other problems that can reduce the engine's reliability. I modified it with a Cylinder #4 cooling modification to overcome this problem, but my block was not reinforced or built with forged components. As a result, I would have needed to invest around $16K to make a solid, reliable engine with the whole nine yards. Oil consumption: The EJ engine has been known to consume oil at higher rates than some other engines, particularly as it ages. My car had baffles, an oil cooler, and an Air/Oil Separator, but it did not have a dry sump system or Accusump to help oil scavenging during cornering. Not having these items can be a problem for those who do not regularly check and add oil, as running an engine low on oil can cause serious damage. Head gasket failures: The EJ engine has been known to suffer from head gasket failures, particularly on older models. Head gasket failures can result in engine overheating, coolant leaks, and other issues that can reduce the engine's reliability. Timing belt issues: The EJ engine uses a timing belt rather than a timing chain, which can be more prone to wear and failure. Timing belt failures can result in engine damage, and replacing a timing belt can be a costly repair. Overall, while the Subaru EJ engine has been used in many reliable vehicles, it is not immune to issues that can affect its reliability. Proper maintenance, including regular oil changes and checking for issues like oil leaks and head gasket failures, can help extend the life of the EJ engine.
Braking: The STI's braking system may not be as capable as other track-focused vehicles when it comes to sustained high-speed braking. This can be a drawback on longer track layouts with multiple braking zones. I used Stoptech front rotors (2 piece) and DBA 5000 on the back, in combination with DTC Hawk track pads.
Aero: The STI's aerodynamics may not be as optimized as those of other track-focused vehicles, which can result in higher drag and less downforce at high speeds. This can make it less stable and capable on the track, even with the roof wing.
Conclusion: While the STI is a capable and fun car to drive on the road, it may not be the best choice for those looking to do professional road racing. There are other vehicles on the market that are more specifically designed and optimized for track use. For that reason, I highly recommend Mazda Miata or MX-5. My partners at Velocity Warehouse, they are expert on this topic. If you need support on your MX-5, don’t hesitate to contact them at www.velocitywarehouse.com.
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