COMPOUND POWER

Not too many people stick with twin-turbo systems when looking to make power, even fewer take a motor that was never twin turbo and slap a compound set-up on it. But that’s exactly what Philip Botting is doing with his R33 Skyline sedan. It was purchased as an RB20E roughly four years ago, but he has always had a passion for the single-overhead-camshaft (SOHC) RB30 and wanted to see how far he could push it. “I started reading about compound turbo set-ups about two years ago, and it seems the best way to get the best out of both worlds — minimal lag and good top-end power,” Philip said. “I also like the uniqueness and the extra fabrication.” A T3/T4 was selected to act as the primary turbo in the set-up, while a GT45 takes secondary duties — the latter utilizes a .70 compressor housing with 1.00 exhaust housing, and Philip added, “It’s more like a GT42.” The T3/T4 sits atop a Sinco top-mount manifold with Turbosmart Hyper-Gate 45mm and feeds the GT45.

The block has been bored out 0.020 over and fitted with Hypatec turbo pistons, new bearings, and gaskets. Auckland Camshafts whipped up a Stage 4 turbo cam and dual valve springs, while a set of Siemens 660cc injectors has been fitted with a billet fuel rail.

Philip has done all the fab work himself, and, as it sits, the motor is ready to rock, but the wait is on for a Haltech Elite 2000, which is on its way, before the car makes the trip to Advanced Tuning and Performance. It previously made 261kW on 11psi with just the T3/T4, so it will be interesting to see what results the set-up can pull.