The Castrol Edge CBR RX-2 built and owned by Brent Curran needs no introduction here in NZ Performance Car, it has graced these pages many times over the past four years, in plenty of different guises. The full-tube-chassis Mazda RX-2 coupé was built in 2009, and first ran a CBR 13B with single turbo, running a best ET of 7.70 at 277kph by the end of the debut 2009–’10 season.
Brent then built a triple-turbo 20B package, which we featured on the cover of NZPC Issue No. 169. The triple-turbo, triple-rotor set-up was a teenage dream for Brent — it was truly badass, and the package saw him run into the sixes, his car being the first rotary on New Zealand soil to do so (with a 6.99 at 317kph). Looking for more power, Brent changed it up again with a twin-turbo set-up, with one turbo sitting each side of the engine. “It got to the point where we were making so much power we needed an adjustable clutch behind the Lenco, and the funds just weren’t there. We decided to go auto with a convertor, as it would get the car more consistent,” Brent explains. By then he was also growing tired of the 20B and wanted a new challenge, so that package was removed and replaced with a 26B PP, as he had never played with one.
Sitting atop the 26B is Garrett GT60 built by NZ Turbochargers, a CDI ignition, and four 4000cc Moran injectors plus four 6000cc Precision injectors in a custom manifold. The goal is around 1190kW with a conservative 32psi of boost. While it could produce more, this should offer a reliable, low-maintenance 200mph/322kph car. “Technically if we do every mod we would for a 1000hp [745kW] 13B to the 26B, you should be able to get double the power. It’s basically just putting two engines into the one car.”
To allow for the longer engine, the firewall was modified and the 26B sat back into the chassis. Plenty of weight was also moved around the chassis in search of better weight balance. The fact that the new trans is also lighter than the Lenco has meant that overall weight has not increased with the greater
The chassis has always been well behaved, but Brent tells us it is now better than ever.
The new combination was debuted at the end of the 2013–’14 season, and after burning up two trans in early testing, and a few other very minor teething issues, including a BOV falling off at half-track, the RX-2 was straight back into the swing of things with a 7.7 at 181mph (291kph), and a 7.3 at 180mph (when the BOV fell off).
All the work paid off at the final meeting of the year during the second full pass with the new combo, when it ran a 6.89 at 203mph (326.6kph), the fastest elapsed time and quickest pass by a rotary on New Zealand soil, and by a quad rotor anywhere in the world. Brent then backed it up with a 7.0 at 199mph with a slight pedal to keep in the groove and then a 6.90 at 203mph to end last season on a high.
With the mechanicals sorted Brent has recently given the car a bit of a birthday present with a new look and new Castrol graphics, which he debuted at the recent Speed Show. Now all he has to deal with is the agonizing wait until the season begins in October, when NZPC hopes to see Brent run deeper into the sixes.
Brent and the CBR team would like to thank Castrol for its continued support.