Racecar Profile: 2015 Subaru WRX STI Rally Car (NR4 Spec)

By Winding Road Staff

June 18, 2015

Subaru’s newest WRX STI is ready to be unleashed on rally circuits around the world. Constructed to meet the FIA’s new-for-2015 NR4 technical regulations, it is the newest Subaru WRX STI production rally car that is eligible in WRC 2, ERC 2 and other regional championships.
Built by the motorsport preparation specialists at JRM Group in Northamptonshire, UK, an official Base Team of Subaru Tecnica International (STI) and the winners of six WRC production titles and 47 world rallies, JRM believes its latest NR4 challenger will its competition a serious run for its money in the WRC 2 Production Cup.
 Steve Smith, JRM senior sales manager, had this to say of the new car:
“This is the newest production rally car anywhere in the world and has been built specifically to meet the FIA’s new NR4 regulations that have been introduced to create more of a level playing field in the production category. There’s been a dearth of new cars coming into production rallying during the last few years so we’re aiming to shake the category up by introducing a car that is totally new and fresh. As a 2015 model, this NR4 WRX STI brings the very latest vehicle technology – that Subaru has developed for its road-going variant – to rallying’s production category. We’re expecting that to represent a significant step in performance that will benefit crews who are serious about winning the production class at all levels of competition.”
JRM’s latest-specification Subaru WRX STI has been heralded as the Japanese manufacturer’s best handling production-spec rally car to date due to improvements in rigidity and suspension enhancements in the production vehicle. We noted the same when we drove both the standard WRX and WRX STI road cars last year.
“This 2015 car features Subaru’s latest vehicle technology that has never been used in the WRC 2 Production Cup. We expect it to be competitive,” Smith added.
Here are the technical specifications for the new rally car:
  • Subaru 2.0-litre, flat four turbo
  • Maximum power output: 280 BHP @ 4250 rpm
  • Maximum torque output: 560 Nm @ 3000 rpm
  • Variable inlet and exhaust camshaft
  • Two stage anti-lag system
  • Homologated intercooler water spray
  • Homologated coolant radiator
  • Stainless steel exhaust system with silencer and catalytic converter
  • Hewland 5-speed dog gear kit
  • Front and rear limited slip differentials
  • Electronically controlled centre differential
  • Heavy-duty front specification driveshafts
  • AP Racing paddle clutch assembly
  • Target homologated minimum weight: 1393 kg
  • FIA/JRM welded safety cage
  • 80-litre racing bag tank
  • Quick disconnect refuel couplings
  • Öhlins dampers with three-way adjustment
  • STi / AP Racing homologated brake package for tarmac and gravel
  • Driver adjustable brake bias
  • Hydraulic hand brake with Manual Lock
  • Motec M800 with drive-by-wire throttle engine controller
  • Motec SDC centre differential controller
  • Motec display screen
  • Sparco steering wheel
  • Sparco Pro ADV fibre-glass HANS seat
  • Sparco 6-point harness
  • FEV 3kg-mounted extinguisher system
  • FEV hand held 2.0kg
  • Helmet net
  • First aid kit
  • Wheel brace and jack
  • Map light
  • Heated front screen - £475.00
  • Bonnet lamp pod assembly - £2,995
  • Roof vent assembly - £1,750
  • 8” x 18” aluminium (asphalt) – £275
  • 7” x 15” aluminium (gravel) – £160
  • Approximate costs of major unit rebuilds:
  • Engine after 1,500 km – £6,500 (plus any turbo costs)
  • Gearbox/diff inspection every 1,250 km – from £1,950
  • JRM NR4 Subaru WRX STI: £99,995 ($158,700 US) 
Interested parties can get more information at JRM’s site or contact them directly here:

Steve Smith
Email: ssmith@jrm-group.com
Phone: +44 (0) 7590 851 862