It's weird. When you think about hauling arse in a Nissan, you invariably think of the top-line Skyline GT-R. I mean, with the traction of its electronic four-wheel-drive and immense tune-up potential, how could you go possibly past it? Testament to this is the fact that Australia's fastest GT-R has run 10.8.
Put that notion to on hold for a moment though, because - at present - the fastest street-bodied Nissan in Australia is actually a R33 GTS-T. Yep, the rear-wheel-drive, single-turbo 2.5-litre "little brother" to Godzilla. David Chapman of the Gold Coast owns this scorching R33 Type M, which has recently reeled off a best ET of 10.62 at 127 mph!
So how did he do it with - of all things - a GTS-T? Simple. With a combination of traditional drag racing performance techniques. Namely, a race prep'd auto trans with a high-stall converter and a grippy set of slicks. Oh, and a fair whack of nitrous-assisted power as well!
After purchasing this vehicle and equipping it with a 3-inch exhaust, K&N filter, AVO blow-off valve and a GReddy Profec B boost controller (taking it up to 9 psi), it didn't take long before the original 4-speed automatic trans dropped its guts. And that was with - what was then - only 15.1-second quarter mile performance.
David increased his chances of going faster by fully rebuilding the stock trans with a 3000 rpm stall converter and a shift kit. This accompanied some work by Sub Zero Performance - who advanced the timing, upped the boost to 14 psi and ran a diet of Avgas/toluene. David was pretty happy with the resulting drag strip improvement. His big R33 now moved to the tune of 13.4 seconds over the Willowbank 400m. Not bad at all.
Luck soon ran out, however, when the RB25DET motor cracked a couple of ring lands. Y-ouch.
At that stage, the most attractive option for David was to rebuild the motor to withstand even more power. Sub Zero stripped 'er down and built 'er back up again with a knife-edged and balanced crank, shotpeened and balanced rods and a set of Weisco forged pistons. These provide a static compression ratio of 7.8:1. Note that standard Nissan rings and bearings are used. Following this, the already-pretty-good DOHC 24-valve head was then ported out and re-packed with standard camshafts. After unsuccessfully trying a copper gasket, a standard Nissan item is now being used to seal head to block.
With the bare motor done, the Sub Zero guys then fabricated a custom exhaust manifold onto which they - initially - installed a big T3/4 hybrid turbo. This tubular manifold also incorporates a Sub Zero fabricated 42mm external wastegate to limit boost pressure. A Simoto air filter is clamped onto the compressor housing for everyday street use.
With a copious volume of induction airflow anticipated, a K&J air-to-air intercooler core was purchased and Sub Zero fitted end-tanks and plumbing to suit the R33 nose. A big GT-R front bar was fitted to give some extra space and - while they were at it - the matching rear wing and skirts went onto the body as well. A Sub Zero developed blow-off valve and oil breather catch tank was also whipped up while the metal working gear was out.
Returning to the engine itself, induction air is throttled by a large Ford Falcon XF butterfly. Note that a custom plenum chamber has been fabricated to go atop of the standard lower section of manifold. This polished cylindrical plenum contains six trumpets to aid airflow into individual each runner. Looks trick, doesn't it?
Engine management wise, the Japanese computer was ditched to make way for a MicroTech MT8 programmable unit. Using just an in-built MAP sensor for a load input, the Sub Zero guys came up with their own fuel and ignition maps on their in-house chassis dyno. Squirting fuel into the combustion chambers are six Mazda 12A turbo injectors connected into a custom rail, a Malpassi rising rate pressure regulator and a high-flow Bosch pump. A standard lift pump is used to keep an in-boot surge tank in surplus supply of juice. At present, the car still retains the services of the standard Nissan direct-fire
coils.
Interestingly, David's car has the assistance of a single nozzle 60hp nitrous shot to help it achieve its 1.6-second 60-foot time. The giggle gas is pumped in just prior to the XF throttle body and we're assured that it's only used to help it jump off the line. There is no nitrous assistance once it gets going.
With a now-revised turbo location - along with the hardware to generate a lot more power - the existing 3-inch exhaust system was next upgraded to 3 ½-inch mandrel, running an A'PEXi polished rear muffler. It sounds
s-w-e-e-t.
With the big-horsepower engine barely fitted to the car, it wasn't long before the standard 4-speed auto threw yet another wobbly. Sub Zero tells us that it was difficult to come up with any accurate dyno power figures because the trans was slipping so much. Fortunately, the ideal fix-it solution fell into David's lap at last year's Summer Nats - where he had a chat to Hugo of RaceMatics. The name RaceMatics may ring a bell to some readers. They're the mob that builds up the transmissions used in Melbourne's JPC-enhanced 10-second Commodore VL turbos. Once swayed, David ordered one heavily-tricked Trimatic auto along with a 4000 rpm TCE converter. Sub Zero then installed the unbreakable Trimatic trans and linked it to work with the standard R33 gear selector. So far - as expected - there have been no more trans hassles.
Amazingly, the R33 Skyline retains its standard LSD differential. David says it must be "unbreakable".
Soo - with an R33 GTS-T currently capable of running 10-second quarters, it must be cranking out some serious Mr Eds, right? Right! After initially trying to chassis dyno the engine with the aforementioned T3/4 turbo and slipping standard trans, Sub Zero decided to upsize the turbo to a custom Turbonetics T60-1 as soon as the gutsy Trimatic went in. With this in place, the RB25 has recently recorded a stompin' 412hp at the back wheels (on the Sub Zero Dyno Dynamics chassis dyno). That figure was attained on 28 psi boost and running C16 unleaded jungle juice.
As you might imagine, the R33 GTS-T had an essential need for some serious tyres. It wouldn't be fair to channel so much torque through a pair of back rubbers from Bob's ReTread Shed. For strip work, David opts to fit a pair of Mickey Thompson street slicks to the standard Nissan 16-inch rims. Simmons OM17s and 245/40 Dunlop Le Mans 701s are run front and rear for street use. Oh, and the relatively soft standard Nissan suspension has also been firmed up with the fitment of King's super-low springs. Shockers are stock.
For street driving, David admits that his car is "a bit of a lard wagon" off the line. But that's only because he can't really stall it up and give it a nitrous prod while he's running the street tyres - they'll simply ignite. On the strip though - where this R33 has been designed to run - it's a totally different kettle of fish. As we said, its 10.6-second quarter mile is presently better than any other street-bodied Nissan.
Skyline GT-R owners - the pressure is on!
Contacts:
Sub Zero Performance
+61 7 5571 7077
RaceMatics
+61 3 9335 1011
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