If you’re a GT-R fanatic, Australia is one of the best parts of the world to get your kicks. For one, builders Down Under love to take their R32, R33, and R34 Skyline GT-Rs past 1,000 hp by using Nissan RD28 diesel engine blocks instead of the legendary RB26 fitted from the factory.
We’ve yet to meet a GT-R enthusiast who doesn’t enjoy using the machine’s Godzilla nickname, which comes from Australia. Between 1990 and 1992, when Nissan had resurrected the GT-R badge via the R32, the race cars that had led to the birth of the road-going homologation special grabbed no less than three titles in the Australian Touring Car Championships.
Plus, the country’s infamous Bathurst 1000 race saw the Nissan demolishing the local Fords, as well as BMWs and others. As a result, Aussie magazine Wheels called the GT-R Godzilla, and here we are, talking about it three decades later.
Building a Skyline GT-R with over 1,000 hp means the RD28 diesel block is one of your best options
The first two GT-Rs were RWD coupes built in the late 1960s/early 1970s , and the still-fighting R35 is a separate breed, but the R32, R33, and R34 GT-Rs are different evolutions of the Skyline platform. And while the ATTESA E-TS intelligent AWD is what gave the Skyline-based Nissan halo car its amazing handling, the icon also owes much of its reputation to the tunability of its RB26DETT (2.6L) twin-turbocharged straight-six, which mixes a cast iron block with an aluminum cylinder heads.
However, while the RB26 has been taken to 1,000 hp on countless builds via forged internals and big turbos, the factory block can crack above 650 wheel horsepower.
And one of the ways to ensure your engine stays strong when aiming for a build that goes past 1,000 hp and wish to use a factory block is to go for the RD28, a 2.8L turbo-diesel straight-six.
In theory, a gas engine, which doesn’t need to deal with the higher compression ratio of a diesel (17:1-20:1), will use a lighter—and also less stout—construction. How about this as an excuse to put together a Cummins diesel-swapped Lamborghini Gallardo?
However, Nissan’s RB six-cylinder family, which goes from 2.0L to 3.0L, was strong enough to deal with such demands. And this is why the carmaker’s engineers built the RB28 diesel based on the RB. The two share the cast-iron block and alloy cylinder head construction (among others), use the same bell-housing bolt patterns and engine mounts, while swapping cylinder heads only requires limited effort.
The earlier RD28s had been used on various Nissan models starting in the mid-1980s (even the R31 Skyline), but these diesels first reached Australian shores under the hood of the Patrol SUV in the mid ’90s.
So while the thought of having an extreme Skyline GT-R with a diesel block—also offered on a Nissan Civilian Bus—might sound crazy, it works like a charm.
In fact, in the Motive Video below, you’ll see a real-world testing-backed comparison between the following Nissan blocks: RB25DET (non-GT-R Skylines), RB26DETT and RB26DET N1, RB30 (R31 Skyline, Y60 Patrol, multiple Holdens) and, of course, the RD28 diesel. And the RD28 arguably has the edge in terms of mega-horsepower GT-R builds, as explained in the comparo against the RB30 gas unit.
Some of the world’s fastest Godzillas at GT-R Fest 2023
However, both units (RB30, RD28) have demonstrated their abilities at the drag strip, which brings us to the final part of the story, namely the past weekend’s GT-R Fest 2023.
Held at the Sydney Dragway, the event brought together some of the world’s most extreme Godzillas, and you can see two of them in the image gallery below—these RD28 street-legal GT-Rs were built by Dahtone Racing.
The beasts were documented by Larry Chen, the famous Californian car photographer whose collection includes a 1990 R32 GT-R.
This R32 GT-R sports a Nitto 3.2L stroker kit along with a Precision 8685 turbo, and a MoTec ECU, so it makes over 1,200 hp. A Turbo 400 transmission sends the power to all four wheels, genuine Volk TE37s with a beadlock conversion. And, the gathering saw the machine pulling an 8.72s quarter-mile at 163 mph.
Then there’s the R34 GT-R “reaprr” of Brett Reid, whose RD28 also features a Nitto 3.2L wide journal stroker (they call these RB32s), as well as a Precision 7275 turbo, making over 1,000 hp. A paddle-shifted Samsonas 6-speed sequential sends that to all four wheels.
Larry has dived into a full video review on the Dahtone Racing R32 GT-R and we’ll update the story with the clip as soon as this is ready. Until then, keep in mind that other parts of the world also have their way of worshiping Godzilla, like the impersonations of Nissan Cefiro drift cars from Thailand, which are a way to keep the budget somewhat reasonable while sliding like a pro.
