Two special cars ventured onto the ice at Lake Champlain in Northern Vermont recently for an exclusive photo shoot. The SRT USA #75 prepared by Vermont SportsCar with the new generation 2015 Subaru WRX STI prepared by Fuji Heavy Industries in Japan. What did it take the team at Vermont SportsCar to transform the new WRX STI into a rally car?
2015 Subaru WRX STI prepared by Vermont SportsCar
Vermont SportsCar has been working on the new STI rally car for a year now and its already got two wins under its belt this season. Here’s what goes into a championship rally car and all the modifications the team did to the stock WRX STI.
On the outside, SRT USA #75 gets special METHOD Race Wheels MR502 VT-Spec -15 x 7 gravel rally wheel. The body has special composite bumpers, fenders and rear doors, composite under-floor protection, a carbon fiber rear wing, STI carbon fiber roof scoop, aluminum sump guard and stainless steel differential guard.
The rally car also comes with a Heated front wind shield and polycarbonate side and rear windows. It gets special PIAA HID driving lights housed in carbon fiber, hood and bumper mounted, light pods for night driving during the January/February rally races.
On the inside, the 2015 STI gets a full Rally America / FIA Open Class specification roll cage wrapped in a seam-welded shell. It gets RECARO SPA ProRacer seats with HANS (Head & Neck Restraint) and Sabelt harnesses. It also comes with a carbon fiber dashboard, carbon fiber door cards and carbon fiber co-driver footrest and GEMS digital driver and co-driver displays. Under the floor, it is fitted with FIA FT3.5 fuel cell, 75+ liters.
SRT USA #75 uses the Subaru horizontally opposed 4-cylinder boxer engine that is turbocharged and intercooled and pumps out approximately 330 hp and 480 lb-ft torque (With a Rally America Open Class mandated 33 mm restrictor). It gets fitted with a Garrett motorsport turbo (TR30R). The team uses Royal Purple fluids throughout with XPR 20W-50 Racing Motor Oil, Royal Purple MAXGEAR 75W-90 & 75W-140, Royal Purple MAX EZ Power steering fluid and Royal Purple PURPLE ICE coolant additive.
The STI’s engine gets rid of the exhaust through a Good Fabrications custom exhaust manifold and Good Fabrications stainless steel 3-inch with quick change car system. The engine management is controlled with a Cosworth Pectel SQ6M ECU and OBR Power Control Module and switch units and GEMS data logger. The electrical system uses a special PRS light weight motorsport wiring loom.
Transmission and Driveline
The STI rally car transfers power to all four wheels through a SADEV 6 speed sequential dog-engagement gearbox. It gets modified with Sadev custom driveshafts, Sadev custom propshaft and motorsport controlled central drive release. It uses Sadev differentials (front & rear), a Tilton racing clutch, STI quick ratio steering rack (11 to 1) and motorsport high flow power steering pump.
Underneath, the rally car gets a Reiger competition suspension with tubular front and rear cross members and suspension arms and links developed by Vermont SportsCar. It also features modified STI hubs and spindles, Alcon gravel rally brakes, Endless brake pads and hydraulic handbrake by Vermont SportsCar. The special METHOD rally wheels are wrapped in DMACK rubber on all four corners. Total weight of the STI rally car is regulated minimum limit 2900 lbs.
SRT USA and Vermont SportsCar have not revealed the total cost of transforming the 2015 Subaru WRX STI into the SRT USA #75, but it won’t come cheap. If you want to build a rally car, you can see it takes a major commitment to the sport to produce a winner. Next up is the Oregon Trail Rally April 24-26 in Portland, Oregon. Stay tuned.