With 19 years of very successful race history between Subaru and UK motorsport legends Prodrive, it would come at no surprise to anyone that Prodrive are the guys behind the record hunting Subaru WRX STi Type RA NBR Special, which last week set the Nürburgring Nordschleife record for a four-door saloon with Kiwi Richie Stanaway behind the wheel. Smashing the previous record held by Porsche with a time of 6:57.5.
The NBR is no stranger to the record books, having previously set the Isle of Man TT record in 2016. Since then the car has been redeveloped in anticipation for the assault on the ring. Despite the fact it’s about as hardcore as a WRX you’ll find, it’s kept clean and simple in appearance, make no mistake the under pinnings are exactly what you’d expect from a car that’s rolled out of the Prodrive workshop.
The base is a 2017 WRX STi sedan that’s had 700 hours of fabrication and preparation poured into it. This began by heating up the American sourced 0km shell to 400 degree celsius and dipping it in an acid tank. The FIA-spec roll cage is a very extensive piece of kit that ties in the usual suspension points, as well as the front and rear subframes. The result is a chassis that’s seven times more rigid than when it left the Subaru factory.
The suspension package consists of XTC four-way adjustable dampers with roller bearing internals to reduce, if not eliminate friction. Through the suspension you’ll find roller bearings used in place of bushes. The hubs are from their most recent WRC campaign with Subaru as are the 380mm two-piece rotors and eight-pot AP Racing calipers with four brake pads.
The aero package, and in particular the rear diffuser looks to be very similar to the one used on the Aston Martin GT3 built by Prodrive. This is joined by a flat floor and pretty low-key front spiltter. This is reworked from what was used during the TT campaign and is reported to make 295kg of downforce at top speed.
The most trick piece found in the aero package is without a doubt the DRS (drag reduction system) equipped carbon wing. This means the wings angle of attack can be changed from 14 degrees to 0 degrees in 20 milli-seconds from the touch of a button on the steering wheel. This can also be fully programmed through the ECU to work automatically on any circuit the team map.
The other side of the grip equation is the 18-inch Prodrive wheels wrapped in BTCC spec’d 245 wide slicks.
The heart of the package is an EJ20 producing upwards of 600HP and 800Nm, which was originally developed for WRC, but has since been reworked as the demands this chassis put on it saw that old version in the bin after only 600km. Now dry sumped with newly designed crank, rods and pistons. Uniquely, detonation is not a concern with this engine, instead head lift is mapped using a pressure sensor. The team run Elf Racing 102 octane, while the ECU and injectors come from McLaren, with the ECU being an early 2000s F1 unit.
A very complex pneumatic paddle shift system is used on the XTRAC six-speed with custom gear ratios to allow for speeds in excess of 180MPH. Uniquely the box isn’t sequential, instead its an H pattern with dual actuators that mimic an h-pattern movement with one pluck of the paddle. It’s the same system Prodrive used in WRC, which allows a driver to select neutral instantly instead of having to search through the sequential in the event of a spin. Gear changes happen in 20 mili-seconds.
Subaru are yet to release the official video of the record setting run, but in the meantime here’s some highlights from Goodwood FOS 2017 to give you an indication on just how quick this car actually is. ‘Oh, and it sounds damn amazing!
Images: Prodrive