Is a brand new HSV with 470kW on tap too good to be true? Read on and find out.
My first thought when I was told Ebbett Holden was selling Walkinshaw Performance-enhanced 470kW HSVs off the showroom floor was: “Who’s inflated dyno figures are those?” How wrong I was. I can happily comfirm that claim as being true.
Four hundred and seventy kilowatts is a whole lot of power in anyone’s language. Most car enthusiasts dream of owning something with that much grunt, or spend years building one. Now, thanks to Australian company Walkinshaw Performance and its New Zealand agent, Ebbett Holden, it’s available to anyone with the cash.
As Holden just released the most powerful Aussie production supercar yet, the HSV W427, there is a bit of confusion between this Walkinshaw and that, as the W in W427 also stands for Walkinshaw. While from all accounts the W427 is an amazing car, it retails for $199,000 and produces 370kW from its naturally aspirated 7.0-litre (427ci) LS7.
This Walkinshaw, dubbed the WP470, started life as an HSV Clubsport R8, with a 6.2-litre 317kW LS3 engine. Stock standard, the R8 retails for $80,000. As featured here the asking price is $120,000, but the added cost is well worth the money.¨Although the Walkinshaw performance upgrades Ebbett is offering are as yet relatively unknown, the Walkinshaw brand is synonymous with high-performance Holdens. Usually any type of aftermarket performance enhancements would void a new vehicle warranty, and in a way they do. HSV’s warranty is long gone, but Ebbett and Walkinshaw are so confident in their products that they will include a factory-style warranty in the purchase price of a Walkinshaw vehicle.
It’s possible to spec any new Holden or HSV with Walkinshaw parts, but to keep it simple we will focus on the WP470, which we were lucky (make that very lucky) to have the pleasure of driving for a few days. Nestled in the valley of the LS3 is a Harrop 122 supercharger and water-to-air intercooler, which is responsible for a large chunk of the 150-odd-kW power increase over factory. Rather than just slapping on the blower and hoping for the best, the vehicle’s fuel system is also upgraded, and the ECU reflashed to suit. The ECU tweak in itself is worth a good chunk of power in these cars, and when combined with the blower, the potential is huge. Due to higher flowing heads, the 6.2-litre LS3s show great results when blown compared to the 6.0-litre LS6 the HSV vehicles came with until recently. Reportedly, the same package on a 6.0-litre is still good for around 420kW, so don’t bee too disappointed if you own one and want some Walkinshaw goodies.
The supercharger pumps 8.6psi of air through the motor, and when you combine that with the 10.7:1 compression ratio of the LS3, you soon see why the power comes on like a switch.
What surprised me was that the car still runs stock headers. No doubt even more power could be unleashed if these were replaced with higher flowing tubes. From the cats back the exhaust is all Walkinshaw though, and despite the power produced, it is remarkably quiet. Or perhaps it was just that the whine of the blower up front is so prominent, you forget about the noise from the car’s rear.
The six-speed manual gearbox has been mated to an aftemarket clutch to handle the added torque the supercharger provides, which is none too shabby at nearly 800Nm. How long the gearbox would last, I’m not too sure. The wise option would be to fit a Corvette-sourced T6060 if the box ever did decide it didn’t like the pressure any more.
Rather than just throw huge power at the standard brakes and suspension, the stock four-pot front brake callipers, which are generally regarded as huge, have been replaced with larger six-pot items. The stock rotors remain, and that’s not a bad thing as they are 365x32mm from the HSV factory.
The reason these cars are built on Clubsport R8s rather than the higher spec GTS model is that the GTS has magnetic ride control suspension, which makes changing it a little awkward. The R8 has no problem being fitted with lower and firmer springs, and that’s exactly what’s been done here. Not only are the Walkinshaw springs 30mm lower than stock, they are also marginally firmer.
This article is from NZV8 issue 45. Click here to check it out.