Moving from a Honda Civic to a R33 Skyline GTS is usually a pretty major leap. The big 2-door Nissan's 2.5 litre turbocharged straight six is virtually guaranteed to set any Civic driver's hair alight. But not in every case... You see, Jason Ma's previous Honda Civic was a one hundred percent Hiroshima screamer. Converted to VTEC technology and hung with a fairly reasonably sized turbocharger, it was a truly lethal street machine. It was also a real bastard to get all the power down...
This traction problem was - largely - solved when Jason sold the Honda to make way for an imported R33 Skyline GTS. A 1994 bog-stocker. Jason made the big jump to a R33 because he likes their aesthetic appeal (and the R32 model looks too old for his tastes). Once behind the wheel, however, he soon discovered that it lacked the excitement of the ol' Honda. The factory 250 horsepower engine and 5-speed made for a brisk ride - but it wasn't the kinda car that could give you a heady rush or entertain you with an abundance of burning rubber.
That situation was soon turned around good and proper!
Stage 1: Mild Bolt-on Breathing Enhancements
Jason started modifying his GTS with the basics - a good exhaust and intake. Out came the factory Nissan airbox and in went a Blitz pod-style filter (hung directly off the airflow meter). As expected, the filter gave a definite increase in response and power. That was complimented by a Tanabe turbo-back 3-inch exhaust, which blows through a high-flow cat converter and single rear muffler chamber. Just like many of the Japanese exhaust upgrades, there are no drones or resonances and the growl of the RB motor is fully acoustically liberated.
Intake and exhaust flows were then further upped by virtue of increased boost pressure. A Blitz electronic system was wired in to give up to 12-psi manifold pressure (standard boost pressure is set to around 7 psi). Releasing the throttle-closed traffic jam between the compressor and throttle body is a polished Blitz blow-off valve.
Stage 2: Installing the Right Base Set-up
Next came the installation of some safety devices that would allow for more power - and, as a bonus, bring more power on their own! In the first instance, the Japanese-spec (designed for 100 octane) engine management computer was hauled out by the fellas at Tony Rigoli Auto. Taking over the role is a MicroTech MT8 programmable ECU, which incorporates an internal MAP sensor. Precise tuning of the MicroTech fuel and (direct fire) ignition system was performed on a chassis dyno.
Intake air temps - and the likelihood of detonation - were further reduced with the fabrication of a Mick's Metal Craft custom front-mount intercooler. Once the 'cooler was installed, however, it was then discovered that the factory plumbing arrangement was causing induction air to get re-heated. The L-shaped pipe that ran from the core to the throttle body (directly opposite the turbo) ran very close to the hottest area under the bonnet (therefore undoing the good job of the intercooler). This situation was remedied by relocating the standard throttle body on a short length of curved pipe on the leading end of the factory inlet plenum.
Stage 3: Forcing the Performance Envelope
As you might suspect, the standard (ceramic turbine) turbo was now at the stage where it was being leant on a little too hard. Its backpressure, turbine reliability and compressor efficiency were the causes for some concern. So - again - the Rigolis set about working their magic under the bonnet. On went their own tubular exhaust manifold, enabling them to mount a notably bigger turbo - a Turbonetics T3/4 hybrid. Exhaust gasses that aren't necessary for generating boost are bypassed thanks to a 42mm Turbonetics external Racegate. This is piped back into the 3-inch exhaust system to keep noise at minimum. The previous Blitz air filter was also replaced by a larger K&N cylinder, which is mounted immediately prior to the compressor.
A turbo set-up like this is designed to run bloody hard. Indeed, extreme boost pressures are what monster turbos are all about. But - before pushing in those big pressures - the stock Nissan injectors had to be upgraded. Increased fuel flow is now derived from a set of six 600cc injectors, which are fed by a made-from-scratch rail and an adjustable pressure regulator. The fuel pump is standard - for now. The big boost shove also called for an oil breather catch can.
Confident of being able to maintain appropriate air/fuel ratios under high boost, the Rigoli guys upped the boost to around 18 psi. Jason was onto a good thing with that package - but, unfortunately, he admits that he "got greedy" and boosted to well beyond 18 psi... The next time the Rigolis saw the car, it was in need of a major mechanical overhaul - almost every piston had been destroyed.
Ouch!
To reduce the chance of this ever happening again, the motor received a rebuild that incorporates a set of forged pistons and the block was also O-ringed. Just the thing to now allow 22 psi boost - enough to generate a recently measured 330 horsepower at the back rubbers. Jason tells us it's a lot easier putting that kind of power through the back wheels than it was with the front-wheel-drive turbo VTEC!
In search for more traction, however, Jason recently advertised the car for sale - in hope of moving on to a GT-R, the undisputed King of Skylines. But, because no serious buyers had been found in the allocated time, Jason has now been forced to take another direction. And it's not a bad one! He's gonna keep the R33 GTS and make it one of the most wicked in the country (if it isn't already!). In addition to recently adding those polished 18-inch Zepters (clad in 235/40 and 265/35 rubber), the suspension has been up-spec'd to Tein adjustable coil-overs at both ends. The suspension improvements - by all accounts - were well overdue... externally, the body kit is very familiar - it's a copy of a R33 GT-R arrangement. Oh, and check out the cool OYEA plates!
Most importantly, the Rigolis are also building Jason a real tasty motor. Using a RB30 3 litre bottom-end, they'll fit the DOHC RB25 head and plunge into no-holds-barred power expedition! Jason is shooting for a stompin' 500+ horsepower at the wheels, probably using a giant T76 turbocharger. Oooo-Yeah!
Jason enjoys the struggle to put power to the pavement!
Contact:
Tony Rigoli Auto (Sydney)
+61 2 9726 6662
|