A young soldier (we’ll call him Luke – ‘coz that’s his name) came into the workshop a few months ago and said “I’ve just bought a Nissan R34 GTT Skyline and I have a budget of $30 – $40K to spend on it – what can you guys do for me – what sort of power can I get from this thing?”
I looked at him seriously and said “What I can do for you is give you some good powerful fatherly advice – go buy a house!”
So we laughed and laughed … and then we had a good talk about what he wanted the car to do for him. A lot of people think that the bigger the number, the better the car will perform. Up to a point, this might be true; but it really depends on how and where the power is delivered that will determine how much fun the car is to drive. What our new customer wanted was a tough but streetable car, with plenty of power in reserve; good handling; and the ability to do some track days at Mallala.
The RB25 was generally in pretty good nick, with good compression on all cylinders, clean coolant, and negligible oil leaks. The body was sound, but the suspension was a bit tired.
The first stage of development was pretty much just bolt-ons. We fitted a set of Tomei Type B Poncams to improve the mid-range response, a Koyo 3-core radiator and Aeroflow oil cooler, Plazmaman polished intake plenum and throttle body, Aeroflow front mount intercooler, Plazmaman billet fuel rail with Bosch 1000cc injectors, and a Garrett 30.76R GenII turbo with external wastegate mounted on a 6-Boost steam-pipe manifold. Waste gases exit through a 3″ exhaust system with Magnaflow resonator and rear muffler, custom fabricated in-house. An OS Giken twin-plate competition series TS2CD clutch with push-pull converter was installed to handle the power transfer. A Z32 AFM and a NISTune modified ECU initially managed the process. A high-volume sump and custom polished alloy catch-can were also manufactured in-house by our master fabricator Shane. Before and after shown below.
MCA X-D Series coilovers all round were fitted to give the car a handling edge, with some drilled and slotted RDA rotors with EBC Yellow pads to improve the stopping side of the equation. Running on E85, the R34 was sent out the door making around 330 rwkW on 16 lb boost – with a warning that it was pretty safe at that level, but the head gasket was unlikely to last very long if we added more boost and the full power potential was tapped too often.
Not too long after, our ever-enthusiastic Luke came back and asked for some more boost – so we dialled it up to 370 kW and repeated the warning … and of course after only a couple of weeks the head gasket did let go during a track day at Mallala, thankfully without causing much damage apart from an engine bay covered in coolant.
Now we’ve done a full RB25/30 build with a first oversize rebore on the venerable 3-litre RB30 block, forged CP pistons (11:1 compression), Drag-Pro I-beam rods, Nitto hi-volume oil pump, ARP studs and bolts, Tomei valve springs with titanium retainers, and Nitto stopper-ring type metal head gasket. The Z32 AFM was replaced with an HPX AFM sitting inside the newly fabricated 4″ intake. It was run in at around 300 kW and then came back for us to unleash its full potential on the dyno. We’re pretty happy with its 420 rwkW at 19lb boost … and so was Luke, as you can see from his expression the first time the external wastegate let rip!