In a world separate from the smog-laden, automotive bureaucratic nightmare that is the United States, a far off land called “Australia” is home to more than its fair share of R32 Skyline GT-Rs. Some are driven on Australian streets and thoroughfares simply as exotic sportscars, but others are subject to a barrage of modifications in the name of straight-line drag-racing performance. Australians tend to be fanatical about drag racing and the Skyline GT-R platform, so seeing one on the road or on a track in Australia is hardly an uncommon sight. To stand out from the norm, Australians have had to aspire for a combination of these goals consisting of full-interiors and street tires coupled with blisteringly fast quarter-mile times in the single digits. In Australia and around the world, achieving this duality of street-driven race-vehicle affords the car entry into an exclusive group of performance vehicles known as Club RH9. It is this club that Paul Diemar set out to gain entry to with his R32 Skyline GT-R, tacking on the desire to be known as the quickest and fastest GT-R to achieve such a feat with low-mounted twin turbochargers.

Text by Richard Fong // Photos by Dean Summers


118-Feat-R32RH9Skyline-007-SideShot(Quick) Runs In The Family

Racing is quite natural for the Diemar household. Diemar’s wife Stacey was the fastest woman in the Super Street Class behind the wheel of this R32 GT-R, affectionately dubbed, “Twoogle”. To aid Diemar’s admission into Club RH9, Twoogle’s RB26DETT mill took a trip to Croydon Racing Developments for reinforcement. The longblock was torn down before being de-burred and acid dipped, after which it received a fresh bore hone. The factory crankshaft was then micro polished and assembled with a set of Cosworth Racing pistons and JUN Auto connecting rods. To minimize the notorious occurrences of oil starvation in the new RB26 assembly, a JUN Auto racing oil pump was installed along with a TOMEI Powered oil restrictor and 9-liter Metalcraft baffled oil pan.

118-Feat-R32RH9Skyline-009-RB26

Easier Breathing

With the new rotating assembly in place, the cylinder head and valvetrain were upgraded to better exploit the RB26’s power-producing potential. Croydon race ported the cylinder head before seating oversized JUN Auto +1mm valves, springs and titanium retainers. TOMEI Powered buckets and shims were installed and measured to ensure proper valve clearance for a set of custom-ground camshafts of undisclosed specifications. The head was then reunited with the block by way of ARP 1⁄2-inch head studs to ensure head-to-block seal integrity, even under extremely high-boost conditions.

Induction Production

While Nissan engineers favored the responsiveness that individual throttle bodies delivered, aiming for peak power figures required optimizing the induction system for wide-open-throttle operation. Thus, the factory individual throttle bodies were scrapped in favor of an aluminum Hypertune manifold with a monstrous 102mm throttle body. The enlarged plenum and straight runners of the manifold distribute the incoming air charge chilled by a GReddy 5-row intercooler to the intake ports. As the charge reaches the ports, a six- pack of Blitz 1,000 cc/min injectors spray atomized race fuel into air stream on the way to the combustion chambers.

118-Feat-R32RH9Skyline-038-DynoSnails Down Under, Horsepower Up & Over

Diemar had already achieved mid-to-low 10-second passes with this setup and a pair of HKS GT2540 turbochargers hanging from the exhaust manifold so he knew that breaking into the 9-second club would require more. A pair of HKS GT-RS turbochargers mated to low-mount stainless-steel manifolds were used to supply more boost pressure and more efficiently satisfy the aspiration demands of the rebuilt RB26 engine. With an A’PEXi Power FC regulating the fuel and ignition timing, the built RB26 turned the dyno’s rollers to the tune of 673 horsepower at 25 psi boost pressure.

Getting Down The Track

While producing gratuitous amounts of power was essential for cutting quicker elapsed times at the strip, getting the power down efficiently was equally important. An OS Giken 5-speed short-ratio transmission was installed and equipped with a custom NPC twin-plate clutch capable of transferring up to 1,000 horsepower. Cusco’s 1-way front differential and a NISMO 2- way rear differential were enlisted to distribute power properly to each of the R32s driving corners.

A set of powder-coated factory wheels from a R34 Skyline GT-R wrapped with Mickey Thompson drag radials translates the engine torque into the R32’s forward movement.

118-Feat-R32RH9Skyline-024-RearSide

Quick 60’s

Since Diemar’s Skyline didn’t produce outrageous 4-digit horsepower, further modifications in the name of efficiency had to be uncovered and exploited to reach the single-digit goal. Losing traction or spinning tires would have been an incredible waste of resources and a preventable loss so the R32s suspension system was upgraded with a set of HKS coil-over dampers. These work in conjunction with a host of suspension links that ensure proper squat and launch geometry, ensuring the largest tire contact patch during each launch. Working on the other end of the power-to-weight ratio, Diemar removed as much weight out of the chassis as could be spared. The interior features the bare essentials for racing in the street class only, including a six-point cage that satisfies the Australian National Drag Racing Association’s requirements for safety and a FIA-certified BRIDE Zeta III race bucket coupled with Willans Harnesses. These modifications, in addition to Diemar’s incessant practice and long hours of seat time, have allowed him to achieve consistent 1.4-second 60-foot times at the strip and completed the final piece of the puzzle that was required for entry into the elusive Club RH9.

118-Feat-R32RH9Skyline-036-TimeslipAdmission Granted

Diemar’s efforts were not in vain as his new setup finally allowed him to break into the single-digit realm and earn a certified and legitimate nine-second time slip. This was followed up with several more 9-second passes, his best of which set his personal best record e.t. at 9.972-seconds at 139 MPH and a lightning- fast 60-foot time of 1.412-seconds. Diemar’s personal 60-foot record also placed him on Australia’s High Performance Imports magazine’s list of top 10 60-foot times on drag radials. Since achieving this feat, Diemar has continued to raise the bar on himself, further improving his elapsed times and securing tenure in the elusive Club RH9 while coyly setting sights on the new, more elusive target, Club RH8.

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SPEC SHEET

VEHICLE
Year / Make / Model: 1993 Nissan Skyline GT-R
Chassis Code: BNR32
Vehicle Weight: 3,333 lbs.
Peak Boost: 25 psi

ENGINE
Engine Code: RB26DETT
Displacement (cc): 2,568cc
Bore & Stroke (mm): 86mm x 73.7mm
Peak Horsepower: 673.8 whp
Peak Torque: N/A
Dyno Type: Mainline DynoLog Dynamometer
Engine Builder: Croydon Racing Developments
Block Modifications: Acid dipped, Deburred, Tapped for 1⁄2-inch Stud
Machine Work: Croydon Racing Developments
Pistons/Compression Ratio: Cosworth Forged Pistons
Connecting Rods / Crank: JUN Auto Connecting Rods
Micro Polished Factory Crank
ATI Race Harmonic Balancer
Camshafts: Custom Ground Camshafts
OS Giken Cam Gears
GReddy Timing Belt
Valves/Springs/Retainers: JUN Auto +1mm Valves, Bronze Valve Guides,
Titanium Retainers, Springs, Cam Cap Studs
TOMEI Powered Buckets and Shims
Cylinder Head Modifications: Croydon Racing Developments Race Ported
Cylinder Head Gasket: GReddy Head Gasket
Head/Main Studs: ARP 1⁄2-inch Head Studs
Intake Manifold/Throttle Body: Hypertune Intake Manifold
Hypertune 102mm Throttle Body
Air Induction System: HKS Racing Suction Reloaded
Fuel Injectors: Blitz 1,000 cc/min Injectors (x6)
Fuel Delivery System: GReddy Dual-feed Fuel Rail
Bosch 040 In-tank Pump
Bosch 044 Inline Pumps (x2)
Bosch Inline Fuel Filters (x2)
Performance Metalcraft Fuel Surge Tank
SARD Fuel Pressure Regulator
Engine Management System: A’PEXi Power FC
Boost Controller: Blitz SBC-iD III Boost Controller
Ignition System: HKS Twin Power Ignition System
SplitFire Ignition Coils
Exhaust Manifold: Stainless Steel Manifold
Exhaust System / Downpipe: GReddy Stainless-steel Downpipes (x2)
GReddy 4-inch Exhaust
Wastegate: HKS Wastegates (x2)
Blow-Off Valve: Blitz Blow-off Valves (x2)
Intercooler: GReddy 5-row Intercooler
Cooling System: Top Secret “Super Radiator”
Nissan N1 Water Pump
Hypertune Coolant Overflow Tank
Oil System: JUN Auto Reinforced Oil Pump
Performance Metalcraft 9-liter Sump
GReddy Oil Cooler
TOMEI Powered Oil Restrictor
Performance Electronics: Blitz Power Meter-iD III
Carel Inlet Temp Meter
Dirt Garage 2WD/4WD Switch
Etc: NISMO Engine Mounts

TURBOCHARGER
Turbocharger: HKS GT-RS (x2)
Frame: T25
Compressor Wheel Specs: 71.1mm Major, 51.2mm Inducer
Turbine Wheel Speds: 53.8mm Major, 47mm Exducer
Turbine Housing: 0.64 A/R

CHASSIS/DRIVELINE
Shocks, F&R (Make & Rate): HKS Hypermax Circuit Coilovers
Additional Suspension Components: Cusco Tower Braces (F&R)
JIC Magic Upper Camber Arms (R)
NISMO Full Rear Arm Kit
Noltec Upper Camber Arms (F)
Rear Subframe Bushings
TEIN Radius Rods (F)
HICAS Delete
Transmission: OS Giken Short-ratio 5-speed Gear set
Line-locker Kit
Clutch / Flywheel: NPC Custom Twin-plate Clutch
Differential(s) (Make & Type): Cusco 1-way LSD (F)
NISMO 2-way LSD (R)
GReddy High-capacity Front Diff Cover
Wheels (Make, Size & Offset): Factory R34 GT-R Wheels, 18×9-inch
Tires (Make & Size): Toyo/ Mickey Thompson Drag Radials
Brake Pads (Front & Rear): Bendix Ultimate Brake Pads
Brake Lines: Stainless-steel Braided Brake Lines
Etc.: Cusco Master Cylinder Brace

INTERIOR
Roll Bar / Cage: 6-point Roll Cage (ANDRA-approved)
Seats: BRIDE Zeta III (D), BRIDE Brix II (P)
Harnesses: Willans Harnesses
Gauges: Autometer NOS, boost and oil pressure
Scuderia Racing Speedometer

EXTERIOR
Front Bumper: Bodyform N1 Bumper
Front Lip Spoiler: Garage Saurus Lip
Side Skirts: Bodyform N1 side skirts
Underbody Diffuser: Top Secret
Mirrors: Ganador

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