We are getting Project R35 GT-R ready for a huge power infusion if you have been following things. Our goal is to exceed 1000 hp with less turbo lag and better driveability than stock. This is a pretty difficult goal as more power almost always means more turbo lag. Of course, getting more power is going to center around bigger and more efficient turbos and the supporting turbo system. We turned to Extreme Turbo Systems for their turbo kit as we feel that this is one of the best stock position turbo systems on the market!
For a turbo system to be great you need great turbos. We have been dying to find a project to run Garrett’s super-efficient G series turbos on one of our projects and now we have that opportunity. We selected a pair of G30-900 turbos to do the job.
When doing the compressor matching, we noted that the G30-900 is rocking out with an efficiency of 77% over much of the engine’s operating range. This is much better than the older equivalent GT series turbo which in itself was no slouch. What this means is cooler charge air temps, quicker spool, and lower compressor power demand so the turbine doesn’t need to extract as much energy from the exhaust flow for less backpressure. The G30-900 also has a good surge margin so the turbo operates far away from surge, important for a fast spooling turbo.
On the exhaust side of things, with an 0.83A/R exhaust housing, the turbine flows over 24 lb/min an outstanding amount for low backpressure.
The G30-900 has a 76mm compressor wheel with a 62mm inducer for a trim of 65. The compressor wheel is a CNC machined forging. The forged machined wheel allows for a much thinner blade profile and hub section. This is one of the reasons why the wheel is so efficient.