Holden Commodore VZ – At All Costs – 52

August 27th, 2010 by NZV8

If you were trying to build the fastest race car in the country, what would you build? Nick Chester chose a heavily modified V8 Supercar.

Regardless of whether you’re a huge circuit racing fan or not, you’ve just got to love the GT1 race class and the cars that compete in it. GT1 is best described as an anything goes, unlimited budget class, in which the cars are only limited by the builders’ imaginations.

Despite being younger than much of the competition, Nick Chester has been racing in similar classes for many years before the forming of GT1. With backing from the family business, Chesters Plumbing and Bathroom, he had huge success in his old Mitsubishi Evolution.

Around two and a half years ago the competition really stepped up, and although the Evo could keep pace, it was getting to a point where it was no longer safe. As he’s a vital part of the family business, and had a new wife as well as a kid on the way, Nick couldn’t risk anything happening, so he decided to build a new, safer car. Of course, there was never any chance that the car would be slower than the Evo, nor for that matter slower than the current front-running cars.

Right Time, Right Place

While the front runners in the class are a mix of locally built vehicles and ex-TraNZams such as John Rea’s Corvette (NZV8 #50), Nick got thinking more and more about who had done the most development that he could take advantage of. The obvious choice was the V8 Supercar series.

After doing a bit of research it was discovered that Western Australia’s Team Dynamik were the leading guys to talk to and, as it so happened, they had the perfect platform to build from. A VZ Holden Commodore shell was being built into a fourth team car, but a lack of funds meant the project was shelved when 70 per cent completed.

Nick flew over to check out the car and the meet the Team Dynamik guys, and a deal was done that saw the car become the basis for the next Chesters Plumbing and Bathroom race car. Team Dynamik also got the job of completing the vehicle. But this was not going to be your ordinary V8 Supercar. It would be something far wilder.

The brief given by Chesters to Dynamik was to do whatever had to be done to make it as fast on the track as possible. While by no means the cheap option, it did mean the car would be quick as soon as it hit the track, rather than being developed over years to become competitive as the Evo had been.

The extensive roll cage was already in the vehicle and didn’t require any changes. However, the suspension, brakes, wheels and aerodynamics have all been enhanced well beyond V8 Supercar regulations.

Having more rubber on the track than the Supercars was the first priority. For this, the rear guards have been substantially widened with carbon fibre replacements, allowing the use of a stock Supercar-width nine-inch-based diff to place the wheels as far outwards as possible. Likewise, the front guards were seriously widened to allow the 18×11-inch rims and 30/65-18 Michelin slicks to turn freely.

If 11-inch-wide front rims don’t sound wide enough for your liking, the rears are a massive 13 inches in girth and shod with 31-inch-tall 71-profile slicks. Fitting the wide rubber to the front wasn’t an entirely simple task, and custom arms have been built to mount the Ohlins TT44 shocks and Eibach springs.

The rear end has a seriously strong four-link setup and some very cool camber adjustable hubs. For on-the-fly fine-tuning of the suspension there are levers within the driver’s reach to adjust both the front and rear sway bars, as well as the rear roll centre.

The Follow-On Effect

With the guards all far fatter than when the car left the factory, the Supercar bodykit that was to be installed also needed serious widening. As with the remaining body panels, the kit is made from carbon fibre, not just for weight saving, but also for strength should it ever end up off the tarmac.

The most impressive looking body feature is the widest rear wing we’ve ever seen. Sourced from a GT1 Lamborghini, it’s nigh on two metres across. On the car’s first outing, it created so much downforce that it bent its mounts, requiring new ones to be made. “I tried driving it without the wing for a few laps and it was just horrible,” Nick says. “I didn’t think it would have made such a huge difference, but it did.”

Before the downforce became too much for the wing supports, the car was driven to a 55.4-second lap around Pukekohe on its first test session. To put it into perspective, that’s faster than a V8 Supercar piloted by someone who has been driving for many years. Once Nick gets used to his car, the times are bound to drop even lower. As it sits, the Holden is already the fastest sedan ever to lap the track.

Pukekohe is considered a high-power track rather than a handling track. But Manfeild, where Nick has been running 1.07s, is a combination of both. Which is not to say that the Commodore doesn’t have some serious power under the hood.

Reliable Power

PM Engines in Wingfield South Australia was responsible for screwing together the package that makes a reliable 760hp and 615ft/lb all day, every day. Although it’s based on a small block Chev, you’d be hard pressed to find any genuine Chev components in the motor. The block is a Brodix item fitted with CP pistons, Crower rods and a Crower crank, giving a capacity of 412ci.

While the bottom end may be as close to bulletproof as money can buy, it’s the top end of the motor where the power is made and the real fruity bits lie. Hidden below that awesome carbon fibre air box is a custom Morrison crossover intake manifold that has been tuned for maximum power and torque. It actually scoops fresh air from ducts in the front bumper, as does a large PWR radiator and oil cooler combination. A large Bosch fuel injector points right down the mouth of each inlet runner and provides fuel from a pair of boot-mounted Bosch pumps. The MoTeC ECU that controls the whole setup also controls eight MoTeC CDI ignition coils, and provides datalogging of multiple aspects of the engine’s behaviour.

The canted valve heads have been CNC ported and fitted with Manley titanium valves along with T&D rockers, which are activated by a Comp Cams cam.

Because the engine is under such pressure during racing, it will be sent back to Australia at the end of each race season for a full freshen-up.

It’s Everywhere

The boot of a car isn’t normally an impressive-looking place, but the boot of the Chesters Commodore is. The team refers to the busy-looking area as “the robot”. What you see is in fact the combination of a diff cooler, fuel system, dry sump tank and roll centre adjustment for the rear diff.

The interior of the car is also very busy. The contraption on the passenger side floor is an air filter, which is plugged into the driver’s helmet to ensure he receives fresh cool air. Mounted behind the driver’s seat is another cooling device that pumps cold air into the driver’s suit to counteract the immense heat generated when the car is on the track.

The driving positioning is rearwards of standard in an attempt to perfect the car’s weight bias. This has necessitated a custom chromoly steering column to be fabricated, to which the MoTeC dash has been fitted.

All the commands required while driving ” such as activating the pit radio, the pit lap speed limiter and scrolling through the dashboard functions ” can be done from the steering wheel, which is fitted with no fewer than six buttons.

In It To Win It

Everywhere you look are items whose sole purpose is to make the car faster than anything else on the track, and to do so safely. This dedication to winning has resulted in a machine unlike any other, not just locally, but around the world. Although it looks like a VZ Commodore there isn’t really a stock part on it. Even the windscreen isn’t a factory item, but a micro-heated V8 Supercar one. And no, you don’t want to know what the cost of that is by itself!

Most of Nick’s fellow competitors have developed their cars over years of competition. This car has been built with the intention of being the fastest thing on the track right from the start, so no compromises needed to be made. Sure, it wasn’t a cheap build, but it’s been done right, and that means only doing things once, which saves money in the long term.

Despite limited seat time so far, Nick has already scared the regular winners, so it’s surely only a matter of time before he’s permanently standing on the podium.

If you get the chance to check the Commodore out on the track, we highly recommend you do so. Chances are you will never see another car like it.

Holden Commodore VZ – Specifications

Engine: 412ci (6751cc) small block Chev built by PM Engines, Wingfield, SA, Brodix block, Crower crank and rods, CP pistons, CNC ported canted valve Chev heads, Manley titanium valves, T&D rockers, Comp Cams cam, Jesel belt drive, Custom Morrison crossover manifold, custom Dailey Engineering billet dry sump with integrated pump, Peterson dry sump tank, Premier 120-litre fuel cell, two Bosch pumps, Bosch injectors, Weldon regulator, MoTeC CDI 8, eight individual coils, crank triggered, (no distributor), Dynamik custom four into one headers, four-inch exhaust system, Black Mamba mufflers, PWR custom radiator and oil cooler, MoTeC M800 ECU
Driveline: Hollinger RD6S six-speed sequential gearbox, Tilton 185mm carbon triple-plate clutch, nine-inch-based diff, custom housing, aluminium carrier, 35-spline spool and axles, adjustable camber hubs
Suspension: Fabricated double wishbone front, four-link rear, Ohlins TT44 shocks, Eibach springs, driver adjustable front and rear anti-roll bars
Brakes: AP racing six-piston monoblock sprint callipers, 378mm AP rotors front, AP racing four-piston monoblock sprint callipers, 356mm AP rotors rear, AP racing floor-mounted pedal box with bias adjustment
Wheels/tyres: 18×11-and 18×13-inch Forgeline ZX3R centrelock rims, Michelin 30/65-18 and 31/71-18 slicks
Exterior: GT1 Lamborghini wing with Dynamik mounts, carbon fibre doors, carbon fibre guards, custom wide-bodied, Chester Black, painted by Robert’s Crash
Chassis: Team Dynamik full chromoly tube roll cage
Interior: Velo seat, RPM steering wheel with MoTeC SLM, MoTeC SDL dash, MoTeC ACL data logger, Motorola two-way radio system
Performance: 760hp (567kW), 615ft/lb (833Nm), Pukekohe 55s, Manfeild 1.07s, Hamilton 1.26s, Taupo 1.29s

Nick Chester – Owner Profile

Age: 28
Owner name: Nick Chester/Chesters Plumbing and Bathroom
Occupation: Manager
Previously owned cars: Mitsubishi VR4, Evos II,III and VI
Dream car: R35 GTR JGTC
Why the VZ: The Team Dynamik Supercar chassis is a very good starting point as they have been building these cars for a while now and all the R&D has already been done
Build time: Two years
Length of ownership: 2.5 years
Nick thanks: Keiran, Sean, Chris and Simon at Team Dynamik, Simon at DZignFX, Oscar at Supaloc Racing, Pete at PM Engines, Keith at KRMS, Paul and Jean at OD Automotive Performance, Randal, Tim and Janice at Edgell Automotive, Richard at Motorsport Electronics, Glenn at Dodson Motorsport, his crew Greg, Big Ron, Victor, Mat, his parents and his wife

Words: Todd Wylie Photos: Adam Croy

This article is from NZV8 issue 52. Click here to check it out.

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