When the Silvia ceased production in 2002, there was no suitable successor to take over the sports-coupe role that it had been playing. While most of the older Silvias (S12, S13, S14) are used for drifting, the S15 remains comfortably out of reach for most, being a little too new and a little too expensive to be used as merely a drift car. Add to that the fact that the chassis in each generation was only modified slightly with each successor, and you can see very little rationale for buying an S15 for the purpose of drifting.
Unlike the After12 Silvia that was featured earlier this year, this Silvia manages to keep its original engine, but storms down the path for more power with some heavy modification. The pistons were swapped from their original 86mm bore to an 87mm set from CP Pistons with a 9.0:1 compression ratio. Doing so bumps displacement up by a mere 47 cc, but the additional advantage is higher power production on the top end, with more room for larger valves. The disadvantage is a slight sacrifice in low end torque, although this is not as necessary when taking to the track. By having an oversquare engine, higher engine rpm is achievable without affecting piston speed.
The stock turbocharger was replaced by a snail from Garrett, specifically the GT3037S unit. This all-steel unit is usually found in HKS kits, and referred to as the GT30R. Ball bearings allow it to spool quickly with little resistance, as opposed to roller bearings. These turbochargers are known to help engines reach 500 horses with some decent modification. While not quite as responsive as the GT3071R turbo, the unit still offered high performance for a mild 500-1000 rpm increase in turbo engagement point.
To handle the additional pressure, the head gasket was changed to a Tomei 1.2mm metal piece. Tomei 260-degree cams and rocker arm stoppers were also installed for extremely high duration valve opening. GReddy products were used to increase cooling ability for the engine, allowing it to run at higher horsepower figures with suitable reliability. This is especially important given our climate if one attempts to hit the track.
The engine itself is far from new, being used in Nissan’s lineup from the S13 generation of Silvias. To handle all this additional pressure and performance, an Apexi Power FC unit standalone ECU was used to keep the engine from killing itself. An HKS EVC V boost controller was also installed to vary the amount of boost depending on the situation, allowing for better control of the torque curve and preventing sudden application of boost when it isn’t necessary.
The higher specification version of the S15 Silvia got a 6-speed gearbox, but this was eventually swapped for the 5-speed gearbox found in the S14. The main reason for this was that the 6-speed gearbox featured thinner gears which would break when power outputs exceeded 400 horsepower, much like how the original Mini 4-speed gearboxes were preferred over the 5-speed for durability reasons. An Ogura Super Single clutch set ensures proper power transfer without slip due to heating or stripping due to torque.
While this S15 used to have a set of Nismo shocks, Pitworks eventually decided that a set of adjustable short stroke coilovers would do a better job. With more companies offering custom suspension solutions, it is easier to tailor a set for your car if you are willing to drop the extra cash for one. Add to this a set of Hardrace lower control arms and Ultra Racing aftermarket equipment, and you’ve got a very track-ready car. For those who are willing to give up some effectiveness on the street in favor of pushing for more track potential, the short stroke setup is ideal.
Most people are accustomed to hearing of brake manufacturers like Brembo or AP Racing, but KSport is a lesser known brand that originated in the UK. Working closely with the UK Time Attack championship, KSport proved their mettle as a brake manufacturer, and this S15 wears a full complement of KSport calipers and rotors (8-pistons/330 mm on the front and 4-pistons/330mm at the rear). To bring a relatively light car like the S15 down to a standstill should be hardly an issue.
Though this car has seen heavy track use, it still retains a lot of the standard creature comforts that you would expect in a modern sports coupe. A single boost gauge on the A-pillar lets the driver stay on top of the turbocharger, while the remainder of the Defi gauges sit on the passenger side, mounted to face the driver. A touch screen head unit sits in the centre of console, with little else changed. The seats are a pair from Bride, being not quite full bucket seats but with superior body holding capacity when compared to the regular seats found in the Silvias. Pair these seats with camouflage-patterned Beltenick harnesses and you’ve got a very stylish looking combination. A simple Momo design racing steering wheel sits in place of the standard Nissan wheel, offering slightly easier steering control for the driver.
Much like the custom suspension set, there has plenty of work done to the exterior of the car that is entirely custom. It’s rare to find such extensive work done to a tuner car, let alone one that doubles as a daily driver when not tearing up Sepang in time attack competitions or sliding around a cone course for a gymkhana.
The aero kit is completely custom, helping to broaden the wheel arches slightly and flatten the curving of the fenders for better aerodynamics. The vents help to cool the brakes and allow for better engine ventilation. On the front is a nice low lip which helps to smoothen and reduce air flow under the car, as well as to provide some slight ground effect to keep the front wheels planted. The front bumper is no nonsense, serving to prevent debris from reaching the engine bay while providing maximum airflow for the GReddy intercooler. It’s one of the neater jobs we’ve seen, with a very clean finish.
The rear is another story on its own. Most GT wings are designed poorly, either resulting in poor downforce, or no actual effect (thanks to flexing of weak spoiler mounts or the boot lid itself). While the wing itself is sourced from Voltex, the remaining components were custom fabricated by Pitworks, from the brackets (which are cut out of thick sheet metal), to the trunk base which ensures maximum force transfer and minimal flexing.
The rear diffuser is properly designed, replacing the rear bumper with a mixture of angled surfaces and channels that make for a mean looking back end. From the rear, the car looks like it could be a proper Super GT model, save for the fact that the wheels are standard size and the body isn’t excessively wide. The diffuser helps to channel the air and maintain a smooth airflow underneath the car, ensuring proper stability. These aerodynamic kits are hardly found on street cars, but they don’t compromise usability in most situations and look the business on the streets.
Car: Nissan Silvia S15
Engine Mods: CP 87mm pistons, Garrett GT3037S turbocharger, Tial 44mm wastegate, Tomei 1.2mm metal head gasket, Tomei 260-degree 12mm lift in/ex camshafts, Tomei Rocker arm stopper, BC valve springs, Sard 850cc injectors, Sard fuel pressure regulator, Walbro 255l/h fuel pump, ATI super damper, GReddy Type R blow-off valve, GReddy / GREX oil cooler relocation kits, Billion power steering fluid tank, Jun type-GT surge tank intake plenum with 80mm throttle body, GReddy intercooler, Splitfire super direct ignition coil, Pitworks engine spark plug cover ornament plate, GReddy aluminium radiator
Electronics: Apexi Power FC, Z32 MAF sensor, Apexi turbo timer, Defi gauges, HKS EVC V boost controller
Transmission: Silvia S14 five-speed gearbox, Ogura Super Single clutch set
Chassis & Handling: Pitworks custom short stroke adjustable coilovers, Hardrace lower control arms and bushings, Ultra Racing bars
Brakes: Ksport ProComp eight-piston calipers and 330mm rotors (front), Ksport ProComp four-pot calipers and 330mm rotors (rear)
Wheels & Tyres: Prodrive GCO6D 17-inch wheels, Federal FZ201 tyres
Interior: Momo Race steering wheel, Tomei Duracon shift knob, Bride Low Max semi-bucket seat, Beltenick racing safety harness
Exterior: Pitworks custom aero kit, Voltex Type 5 GT wing with Pitworks custom wing bracket and trunk base