The Z Challenge Cup is a little-known series that has been going on in Japan for quite a few years now and has single-handedly pushed the development of tuning parts for Z-cars and the VQ-series engines that power them. Tuners as well as privateers are welcome to join the series, which puts some of Japan’s most track-focused Zs up against each other at places like Tsukuba, Sodegaura Forest Raceway, and Fuji Speedway. With power output being roughly the same among the cars, it’s easy to understand why this has become one of the most fun series out there; driver skills count just as much as the cars’ capabilities. One of this year’s newest entries is a collaboration between two very well-known names in the JDM tuning world. It’s a car that not only impresses for its level of preparation, but one that serves as the perfect example of what a Z Challenge car is all about.
Mizota-san of Revolfe S.A. showed off his latest creation at last December’s Super Lap Battle in Tsukuba, where he turned up with an all-new Z33, created with the help of Ito-san at Do-Luck. The car serves quite a number of purposes. First up it’s a time attack machine to see just how fast the 350Z can be made to lap Japan’s most notorious circuits, second it’s a company demo car for Revolfe, and finally it’s their entry in the Z Challenge.
The Z33 has become quite the affordable performance car purchase, as prices have dropped to an all-time low now that the Z34 has established itself. The Z has always been a GT cruiser rather than a full-on sports car, offering simple and true driving dynamics via the combination of a decent chassis and an honest rear-wheel-drive layout. So while all this makes it a good street car, there were quite a few areas that needed to be addressed to make the Z33 a more focused track weapon. The engine came first. To fit special high-compression forged Revolfe pistons, the VQ35 had to be stripped down and the aluminum cylinders bored and honed. The crank and connecting rods were left stock, while Tomei Powered competition bearings were used to ensure high-rpm longevity on the track. To further increase power, Nismo Spec 2 heads—factory-tuned, high-compression items that boast revised combustion chambers—are ported and polished and sport a fully upgraded valve gear with larger and lighter valves as well as high-lift springs. The compression rises from 10.3:1 to 12:1, and to utilize the higher compression, Mizota-san went ahead and added Tomei Powered 272-degree camshafts and Power Enterprise 0.7mm metal head gaskets. A custom 90mm induction pipe helps boost the amount of air that enters the engine, scooped up from the front of the bumper thanks to the Do-Luck air intake and upgraded filter fitted in the stock airbox. The exhaust system starts off with Revolfe high-flow exhaust manifolds then dumps to Power Craft sports catalysts (in place to meet the Z Challenge regulations) and finishes up with a Power Craft Z Challenge race exhaust. Along with the Revolfe flashed stock ECU, an HKS F-Con IS piggyback computer was added and custom mapped by Ito-san at Do-Luck to get the most out of the newly built engine. Power sits at 370 hp with the kind of immediate response you would expect from a big-displacement, naturally aspirated motor. Additional upgrades include a Trust 22 row oil cooler and an RG racing radiator. Transmission-wise, the factory six-speed gearbox has been joined by an ORS twin-plate carbon clutch with lightweight flywheel for blistering-fast gear changes while the Tomei T-Trax two-way helps to efficiently distribute power to the rear wheels in all sorts of tricky conditions.
Revolfe, a proven builder of crazy high-speed wangan beasts, has always given a lot of attention to suspension, advising customers to never take the cheap route when addressing their car’s handling. So it’s no surprise that the Z33 runs custom-built two-way-adjustable Revolfe dampers with a twin-spring setup (the spring rate varies depending on the different circuits the car is driven on). Joining these dampers are polyurethane bushings all round that help stiffen up the chassis and steering feel by replacing the softer and most likely aged stock items. Ito-san at Do-Luck supplied a floor support bar and a front support plate to stiffen up the chassis in critical places. Braking came next, and again, Mizota-san had no intention of trusting the stock setup for the tough job of putting up with repeated abuse on track. So now the front is anchored down with a pair of massive Brembo six-pot monobloc calipers biting down with IDI 750 race pads on 345mm two-piece discs. The rear setup has been treated to 340mm rotors and special custom brackets to reposition the stock caliper, a very common way to boost rear braking bias.
It was great timing that when Mizota-san began the build of the Z33, Ito-san at Do-Luck had just put the finishing touches on a new, wide-body 350Z aero package. Starting off with the front bumper and wider, Nismo Z–tune-style flared-out fenders, the Do-Luck aesthetic treatment is instantly recognizable and like nothing else out there for the Z. The front bumper features a scoop to feed direct air to the airbox, while a second intake on the carbon hood helps dissipate some heat from the engine bay. The kit finishes up the car with typically deep and angular Do-Luck skirts and a rear bumper that is contoured heavily around the lower part to bring a more evident highlight toward the carbon-fiber center finished and those big bore tailpipes. The low-set GT wing is again something that Ito-san came up with and joins other carbon detailing around the car like the front canards and custom side mirrors, which were made just for this car. The metallic marine blue was a great color choice, helping to show off the complex curves and overall silhouette of the new aero. And, of course, like any demo car, there were plenty of sponsor decals to be applied. Mizota-san runs two sets of wheels on the Z33, both from Weds Wheels. First up, the Weds Sport SA-55M the car was fitted with at the time of the shoot, as well as the new split five-spoke SA-60M as backup. Z Challenge regulations state that cars must not run semislick tires, which is why the 18x10-inch rims are fitted with GoodYear Eagle RS Sports in 265/35R18 at each corner.
Again, regulations of the all-Z racing series state that cars should be in street-spec, meaning that along with sports catalysts and street radials, rollcages are prohibited and A/C and audio systems should be present. This, in turn, makes the Revolfe 350Z a rather easy-to-live-with kind of track car, even if the Bride Vios III bucket seats and Teamtech racing harnesses make it a bit awkward at times. The factory navigation system has been gutted out to open up space for the three Defi gauges to sit in good view on the center console, along with the multitude of additional switches. The only other real gadget that has been added is the HKS Circuit Attack Counter, because this is, after all, a time attack car.
D1 driver Kunnyz took the car out at the Tsukuba Super Battle for the first shakedown, ironing out small issues with the suspension setup. It will be interesting to see how Revolfe will do against shops like MCR, Midori, Garage 4413, and Power House Amuse in this season’s four races. Results aside, Mizota has proved that despite getting on in years, the Z33 is still very much a capable and potentially fast little car.
Specs & Details
'04 Nissan 350Z
Engine 3.5L VQ35DE V6
Engine Modifications Revolfe custom, oversized, high-compression pistons & exhaust manifolds; Nismo high-compression head & upgraded valvesprings and retainers; Power Craft sports catalyst & Z Challenge stainless steel exhaust system; Tomei Powered 272-degree Pro cams (IN & EX) & competition bearing set; Power Enterprise 0.7mm metal head gasket; Custom 90mm induction pipe; Do-Luck filter & duct to air intake; RG aluminum racing radiator; Trust 22-row oil cooler; Revolfe custom oil catch tank; TM Works direct coils
Drivetrain ORC twin-plate carbon clutch; Tomei Powered T-Trax LSD; Evolve transmission oil cooler & differential oil cooler
Engine Management Revolfe ECU; HKS F-Con IS piggyback ECU
Wheels, Tires & Brakes Weds SA-55M 18x10’’ +18 wheels and GoodYear Eagle RS Sport 265/35R18 (front & rear) tires; Brembo front 6-pot monobloc calipers; Revolfe big rotor kit, 345mm (front) & 340mm (rear); Do-Luck braided brake lines; IDI 750 front & rear brake pads
Suspension Revolfe 2-way-adjustable Z Challenge spec suspension & helper spring setup; Super Pro polyurethane bushes; Do-Luck floor support bar & front support plate
Exterior Do-Luck front bumper with NACA duct; Carbon canards; front under spoiler; front wide fenders; carbon hood with NACA duct; side skirts; rear bumper with carbon lower section & rear GT wing; Power Enterprise lift-up panel; One-off CFRP aero mirrors
Interior Nardi Rally steering wheel; Bride VIOS III Sport racing bucket seats; Teamtech 4-point racing harnesses; HKS Circuit Counter lap timer & DMR; SHiFT-I; custom carbon switch panel; Defi gauges (exh temp., water temp., oil press., oil temp.)