Garage Revolution's Time Attack FD3S RX-7, Part 1
Text by Eric Hsu and photos by Jeff Naeyaert
I saw the Garage Revolution (GR) FD for the first time a couple days before the 2011 World Time Attack in Sydney, Australia this past August. It was already sitting in one of the garages at Eastern Creek Raceway since Ian and his crew had just unloaded the car the night before from the shipping container. We got out of Ian's “ute” that morning and he took me straight over to the garage where the GR FD was parked. Ian knew that was the car I wanted to scope out since it was the main concern of the Sierra Sierra camp (including myself). Basically my jaw dropped. The GR FD looked like it was built more to the Japanese Super GT GT300 rulebook than it was any time attack rulebook. Check it out for yourself.
The Garage Revolution was #3 at WTAC 2011 – read the 10 Fastest Cars at WTAC 2011!!!
Click to enlarge: At first glance, the GR FD looks very much like a Super GT GT300 race car with a highly developed aero package. Rumor has it that it is in fact an ex-Super GT race car. While that certainly is a possibility, I could also believe that a highly skilled car builder could build a car like this should he have plenty of time and budget at his disposal. Whether it is an ex-Super GT car or not, Garage Revolution has definitely taken this car a step further in the attention to detail department. A Super GT FD also uses a naturally aspirated Mazda 20B 3-rotor engine so a 13B-REW turbo is also a drastic change from the 20B. Aoki-san of Garage Revolution and his team have definitely spent many, many hours building this car.
The Mazda 13B-REW engine sits nestled in the front within a cage of its own with tubes all around it. A large Garrett based GCG turbo sits up high toward the front of the engine to clear the factory Mazda frame rail and shock tower. Both factory frame rails, shock towers, and firewall are still present, but all other factory sheet metal has been replaced by beautifully made single layer pre-preg dry carbon panels. All steel just in front of the shock towers has also been cut.
The V-mounted intercooler is an ARC core and the foam panel filter is from HKS. The perfectly contoured carbon side panels should already give you a preview of this car's level of attention to detail. According to Aoki-san, the GR 13B-REW engines make 650bhp at 1.5kg/cm^2 boost reliably. I asked him what type of apex seal he uses and he said GR only uses factory Mazda two piece seals. At both WTAC and Tsukuba this year, the car ran reliably at both events without issues.
The GR FD uses a Greddy Type-R blow off valve mounted upside down and attached by Wiggins clamp.
Here's a shot of the engine with one of the carbon side panels off. At the bottom of the image you can see where some of the factory sheet metal has been cut away. This picture also reveals more smaller diameter tubes and gussets that tie the shock tower and frame rails into the main roll cage and the smaller cage up front that surrounds the engine. The air box seems to have dual entries: one via HKS foam air filter that is ducted to the hood and the second via silicone duct hose. At the end of the silicone duct hose is just a fine stainless steel mesh. It pulls air from in between the carbon engine bay side panel and the actual wheel well. I wonder if GR found that the engine just needed more air than the original foam panel filter could provide and added the second duct later.