When Warren Gainsmith bought a near-new Australian-delivered Nissan R32 Skyline GT-R in 1992 it wasn't destined to be the King of the Gainsmith garage - it was actually to be nothing more than an "occasional use" car for his wife! Taking residence at the back of the garage behind Warren's twin-turbocharged 351ci Ford Bronco, supercharged Corvette and Bathurst Cobra, the poor Skyline was very much humbled. The Nissan? Well, it was a pretty good carry-bag for driving to the shops...
The GT-R's shuffle from the dark corner of the garage happened several years ago when Warren was faced with a bit of a dilemma - his beautiful supercharged 'Vette hadn't been prepared in time for a tarmac rally to Adelaide. Not one to quit, Warren dusted off the grocery-getter and, much to his surprise, snatched an amazing second position outright in the event! That's when it really hit home: "The GT-R starts off like an artist's canvas," says Warren.
Since then, the GT-R has risen to absolute stardom.
The build-up began in the early '90s and has remained under the roof of Melbourne's AVO workshop - as Warren says, the car is something of a test bed. Over nearly ten years of on-going development, there have numerous mechanical configurations; the current guise is, of course, the best so far. As Terry from AVO explains: "We've got it making 410kW at all four wheels but it's the amount of response and mid-range torque that really makes the car unbeatable in competition."
And competition is the whole focus of this car.
The desire for big top-end power along with strong torque points squarely at an increase in swept capacity. AVO have taken the standard RB26DETT capacity and kneaded it out to 3.0-litre using a RB30ET bottom-end. To achieve this, the block had to be redrilled and tapped to accept the DOHC RB26 head and a custom timing belt was required. APEP forged pistons (providing a static compression ratio around 7.5:1) and aftermarket conrods were also necessary to withstand the massive forces associated with each cylinder firing. A Nizmo oil pump and a large engine oil cooler (installed in front of the right-hand front wheel) are also installed in order to keep the RB26/30 running sweetly. The cooling system comprises a high-flow water pump and large aluminium radiator.
Breathing through the factory DOHC, 24-valve head has been enhanced with a port and polish job, custom ground camshafts with AVO adjustable sprockets, upgrade valve springs but - interestingly - standard valves. A 1.2mm stainless head gasket has proven absolutely problem-free.
(Note - for full details of the 1998 engine build visit "Nissan Powerhouse".)
Rather than go the way of a custom tubular manifold with a dirty great single turbocharger - which is great for max power but little else - AVO opted to Extrude Hone the factory exhaust manifolds and bolt a '400hp' roller-bearing turbocharger to each. Both turbos incorporate an internal wastegate, so you won't find any external 'gates in the engine bay scenery. From the twin turbine and wastegate outlets, AVO has fabricated 3-inch dump pipes that lead into bugger-all-restriction twin 3-inch systems!
With boost pressure set to a maximum of around 1.65 Bar, those twin AVO turbochargers blow through an enormous front-mount bar-and-plate air-to-air intercooler. "It has the potential to run about 1000 horsepower without too much of a problem," says Terry. The air filter and blow-off valve arrangement, meanwhile, comprise parts you'll find in the AVO product listing.
The late-'80s technology factory ECU is now presumably a paper weight around the AVO office and has long-time been replaced by an Autronic SMC programmable system with a MAP load sensor. The fuel system is made up of six 800cc injectors, an adjustable pressure regulator, twin Bosch pumps, ½-inch lines and an all-important surge tank to prevent fuel starvation during those high G-force manoeuvres.
The ignition system uses a CDI unit and upgrade direct-fire coils. A rev limit is enforced at 9000 rpm, but the massive mid-range torque means there's no real reason to ever venture so high.
In its current set-up, Warren's GT-R pumps out an awesome 410kW
at all four wheels on a DTS chassis dyno at around 6700 rpm. This is achieved running 1.65 Bar of boost and Elf race fuel.
As you can see, peak torque is attained at 5500 rpm (which is quite low given the peak power output) and Terry tells us full boost is delivered from as low as 4000 rpm. Response and torque spread are what makes this engine stand out; anyone can make huge top-end power, but it's a lot tougher when you want to maintain good torque at lower revs as well. Throttle response is also very important for a tarmac competition car like this, hence the standard GT-R 6-throttle intake manifold remains.
Of course, you can't lumber the factory gearbox with outputs like this and expect it to live a long and fruitful life. Warren's GT-R now runs a Hollinger 6-speed sequential 'box, which is both 'unbreakable' and offers a great selection of ratios. A triple-plate Tilton clutch is also in service.
Total traction is essential when trying to accelerate the substantially large Skyline out of slow speed corners and the ATS front and rear LSD deliver bags of it. A HKS in-cabin adjustable front-to-rear torque-split controller also varies the car's handling attitude.
Oh, and - interestingly - a carbon fibre tailshaft was being tested at the time of writing; one particular unit supplied from the US broke in its first outing, but a new-and-improved version is about to be put through its paces.
With plenty of drive provided by the tickled AWD system, this GT-R also has great poise thanks to its (re-valved to suit) Tein adjustable struts, Tein front tower bar, aftermarket swaybars and low compliance bushes. The factory GT-R rear-steer system has also been disconnected.
Brakes, meanwhile, are big enough to fit a family pizza - Harrop 355mm discs with 6-pot calipers at the front, and 300mm rear discs with 4-pot calipers. ABS control is still maintained because, as Warren says, "it's an advantage when you turn up to a track you've never seen before." A hydraulic handbrake is also tied to the rear wheels - great for getting the crowds gee'd up with big slides!
Adhesion is ensured by a set of 245/35 Falken road/race tyres worn on 18-inch lightweight Volk rims. Falken is a major sponsor of the vehicle.
Weight is, not surprisingly, a major consideration in a tarmac rally car. Warren has gone to great lengths to keep the '32 light using carbon-fibre/Kevlar doors (which weigh about a third of the factory doors), a carbon rear wing (based on a V8 Supercar design) and front cone with undertray - all the work of GP Sportscars. Perspex side windows are also fitted.
Despite all this effort, Warren reckons the car could still be a little bit lighter - with the fitment of a roll rage, the giant brakes, the big intercooler and radiator and all that other heavy-duty go-fast stuff, the GT-R's kerb mass has failed to dip below 1380 kilograms.
Inside, you'll find absolutely no luxury items; climate control, audio system and carpeting are all gone. There is, however, the essential roll cage, Sparco race wheel and seats, harnesses, rally computer and in-car communication system and a couple of extra gauges. If it doesn't help win races it's not there - and fair enough.
Out in the field, Warren says his GT-R is just about perfect - it points where you want it, there's heaps of grip and there's ample power. He's quick to point out it was never intended as a drag car but, still, it
never loses the 1000m sprints that are sometimes included as part of a tarmac rally. No shocks there!
In terms of competition success, Warren says the car is always up at the pointy end of the field. Despite often doing battle with GT3 Porsches and the like, it has won the Peaks Rally and many other notable events. The only reason the car hasn't tackled Targa Tasmania is it's too modified.
Hmmm, too fast more like it!
Contact:
AVO (Advanced Vehicle Operations)
+61 3 9584 4499
Avo Turboworld
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