What makes a car? What is the single most important component of a car which allows it to function? You might say that it’s the ECU, the body or the wheels. None of those answers are wrong, but the correct answer is ‘everything’. A car is the sum of hundreds of different parts; some critical to the car’s functions, some not so much. But if we all had to name on single part which was absolutely critical to a car, I think we would all agree that that part is the engine.
Without the engine, a car would not run, plain and simple. The car is an empty, lifeless shell without it. It could be said that the engine IS the car.
Engines come in all shapes and sizes, big and small, Straights, Vees, Flats, Twins, petrol, diesel, bio-diesel; the list could go on for miles. Some engines are the stuff of legends, like the RB26 and the all-American V8 flatheads while some engines are best left to rot in the history books and the junkyards. Then there are the magnificent engines built by aftermarket performance tuners…
Mass produced engines, no matter how good they are, are always a compromise. These factory engines have to comply with strict emissions and noise regulations which limit an engine’s true potential. Cost of manufacturing these engines also has to be taken into consideration because of the mass production process. This also limits an engine’s strength and durability. Restrictions like these don’t apply to a race engine builder like Tomei however.
Tomei started out as a tuning factory for race cars and was established as Tomei Jidousha Co. Ltd. in 1968 by Seiichi Suzuki. From the very day that Tomei was founded, the company went on to achieve impressive results in nearly every motorsports category and this gave Tomei the recognition and the credibility that the company has today.
These days, Tomei is the company to turn to if you’re looking for precision built engine which is able to produce big horsepower and run reliably. In many ways, a Tomei built engine is the Holy Grail for car enthusiasts and being able to pop open the hood and see one of these beauties nesting comfortably in your engine bay is perhaps one of the most pleasurable experiences a car nut can ever dream of. Having a Tomei engine is like having Megan Fox as your girlfriend; they’re both extremely well-built and ecstatic to have fun with.
The brightly coloured Impreza we have here is built by ST Powered of Singapore, ST Wangan’s technical and business partner. Built to smash lap records in time attack competitions, one can see from the sum of the parts fitted that this is a car with serious track performance. And what’s under the engine bay? A Tomei engine of course.
The all new Tomei Genesis engine now displaces 2.5 litres and inside this wondrous engine are forged pistons, forged H-beam conrods, thoroughly reworked heads with larger intake and exhaust ports, toughened valvetrain components such as titanium retainers with oversized valves, a forged and fully balanced crankshaft and extremely durable Tomei competition main bearings and conrod bearings. Even the studs have been replaced with strengthened components to ensure the whole engine stays in one piece during the long and hard life it will inevitably lead. Inside the reengineered heads are Tomei Procams with a 264º duration which sacrifice low rpm drivability for top end power.
With the engine settled, the surrounding components needed to carefully selected to ensure that everything would work well in harmony. For a 2.5 litre engine to make big horsepower it needs forced induction and forced induction is what this car has in abundance. An Owen Developments turbocharger, based on Garrett’s huge GT35 turbo, is called in for force feeding duties and it works together with custom stainless steel piping and a large front mount intercooler of unknown origin.
Fuel is fed into the EJ25’s beautifully re-engineered cylinders by Power Enterprise 1000cc injectors which receive their fuel feed from a high capacity external fuel pump and a SARD surge tank. Preventing overboost is a TiAL wastegate and keeping the turbo safe from potentially damaging compressor surge is an HKS Type-II Racing blow off valve. Finally, keeping the engine nice and cool in our hot weather under intense racing conditions is a Tabata racing aluminum radiator and an oil cooler. Finally, handling all fueling and ignition parameters is a highly advanced MoTeC M800 engine management system which works together with an HKS EVC boost controller to tweak boost levels.
For true speed and lap time crushing ability, every component needs to be up to par. One simply cannot risk a single component breaking when every second counts. The drivetrain is an equally important component of a car and ST Powered handled this by replacing the standard gearbox with a 6-speed ‘dog box from PPG. Acting as the medium between flywheel and gearbox is an ORC twin plate carbon clutch and giving the able Scooby maximum traction out of the turns are OS Giken LSDs fitted in the front and rear differentials.
A time attack car not only needs to be powerful, but easy to handle as well for maximum efficiency on the track. When a car handles well, it gives the driver more time to focus on driving the car instead of making constant steering corrections and worrying in fear of when the car is going to spit him out into the barriers in an explosive crash. ST Powered’s Scooby uses a suspension kit from one of the top names in the business, Aragosta. These Aragosta adjustable coilovers come with a remote reservoir and offer exceptional handling characteristics. Giving the chassis even more rigidity are APP strut bars fitted at the front and rear. For added safety and even more chassis rigidity, a 6-point rollcage was also fitted.
As we get further and further down the spec list, some of us don’t realize that these components are actually more important than one gives them credit for when it comes to building a truly fast track racer. Big brakes on a car like this are indispensable as these brakes need to be able to stop the car on a dime under late braking, corner after corner, after corner without fading. And brakes don’t come much bigger on cars than these massive 8-piston Brembo calipers and only slightly less massive AP Racing 4-pistons calipers on the rear.
Far too many people underestimate the true value of a good set of wheels and tyres. A set of rigid yet lightweight wheels will improve braking and cornering performance and sticky tyres will keep the car glued to the track. It’s with these criteria in mind that ST Powered wrapped these massive Advan RS wheels, which measure 18×10 inches, in superglue-sticky Michelin racing slick tyres before bolting them on all four corners.
The completely stripped interior leaves plenty of room but no seating space for passengers. The only amenities left in this Scooby’s interior are the lone Bride Low Max Maxis III bucket seat, a Momo mod 08 steering wheel, Defi gauges and a Defi VSD. On the outside, the Scooby packs some sophisticated aerodynamics in the form of a full Varis Time Attack bodykit and also loses a lot of weight thanks to the carbon fibre replacement doors from Seibon.
Just to drive the point home, every component in a car needs to work well for the car to be truly effective and reliable. Having too much of one thing and not enough of another will inevitably result in an imbalanced car which doesn’t perform. Of course, having a powerful Tomei built engine in the engine bay always helps to even out the odds in any competition…
Car: Subaru Impreza STi Version 9
Engine: Tomei Genesis EJ25 2.5 litre, flat-four, DOHC, turbocharged
Engine modifications: Tomei Genesis engine (includes, crank, pistons and conrods), Tomei 264º Procams, Owen Developments GT35 turbo, HKS Type-II Racing blow off valve, TiAL wastegate, Power Enterprise 1000cc injectors, Tabata radiator, SARD fuel surge tank
Transmission: PPG 6-speed ‘dog box, OS Giken LSD (front & rear), ORC twin plate carbon clutch
Suspension/Chassis: Aragosta adjustable coilovers with remote reservoir, APP strut bars (front & rear), 6-point rollcage
Brakes: Brembo 8-piston (front), AP Racing 4-piston (rear)
Wheels & Tyres: 18×10 inch Advan RS, Michelin racing slicks
Electronics: MoTeC M800 ECU, HKS EVC boost controller, Defi gauges, Defi VSD
Interior: Bride Low Max Maxis III, Momo Mod 08 steering wheel
Exterior: Full Varis Time Attack bodykit, Seibon carbon fibre doors
ICE: Yes, I’d like some in my Coke please.
Tuner: ST Powered Singapore – (+65) 6282 0330 ST Wangan Malaysia – 03-5621 1148