GRAEME SMYTH IS LOOKING TO ADD A LITTLE STRAIGHT-LINE SPEED TO HIS ALREADY QUICK 13B-POWERED FD RX-7, WHICH WE FEATURED ON THE COVER OF ISSUE NO. 238, HAVING SOON FOUND THE LIMIT OF WHAT THE NATURALLY ASPIRATED 13B CAN ACHIEVE
Last year saw Graeme break out of GTRNZ’s GT2 time limits — as he explains: “I broke out of GT2 with the 13B NA [naturally aspirated]. I could run a lap time to win a race no worries, but then, in a handicap race, I’d pass, say, a super tourer or whatever through the midsection, but it would just blast back past me on the straight, so trying to race was frustrating.” The answer was to add a little boost to the equation. The chassis will stay as is, with the only changes coming in the form of the engine. The 13B bridgeport with X-Treme Rotaries quad throttles is now up for sale, with a new Curran Brothers Racing (CBR) 13B based on an FD block ready to slot in the hole. The motor will feature bridgeported plates and be dowelled. An Xcessive lower manifold is mated to an FD top with factory throttle body. Boost will come via a Precision 67/65 Gen II, and the wastegate configuration is yet to be decided.
Like the rest of the fabrication, this is Graeme’s own handiwork. He will also make the intake tanks for the intercooler. The clutch package, Modena six-speed sequential, and nine-inch independent rear suspension (IRS) diff — with new ratio — will remain. A switch to E85 will see a new fuel system added, with a Radium fuel cell with integrated surge tank to be mounted in the rear. Power figures will not be excessive. “The way I look at it,” Graeme tells us, “we are only looking at around 550– 600hp [410–447kW], and it’s on a 280/680R18 slick. That is the same as V8 supercar, and they are supposedly making 500–600hp [373–447kW], so it should get good drive, and mid-corner speed should be no slower than it is. I’d like to think it will go faster than a 29 [1min 29s] at Taupo and a three or four [1min 3s / 1min 4s] at Hamptons.” To ensure that the well-handling FD suffers no side effects from the added weight, weight will be removed elsewhere to counter, with the goal to remain at the 1208kg with Graeme on board. Expect to see the FD running in GT1 and maybe doing some time attack later this year.