Silver Bullet

Supercharged LS1s are now as common as you-know-whats in the Australian go-fast scene. But when Shaun Henrick tells you his ’02 Holden Monaro is fitted with a blower, you’d better be ready for a surprise when he lifts the bonnet. This baby runs a Magnuson/PWR kit for a no-fuss, total performance solution.

A silver bullet.

Shaun purchased this Series 1 Monaro in late 2002 as a run-out bargain alongside the release of the Series 2 version. His motivation for purchasing a Monaro is simple. He loves the styling, it offers good performance outa the box and there’s heaps of aftermarket tuning potential.

Shaun tells us he initially gave the Monaro a basic round of enhancements - as he’d done with his previous Commodore VL Turbo and Ford XR8s. This initial round of mods involved 4>1 headers with a twin 2½ inch exhaust, a home-made cold air induction system, K&N panel filter and an LS1 Edit MAF-less tune. Another important step was the fitment of a shorter 3.9:1 ratio LSD – this gets the big 5.7 litre donk up an’ running.

The beautiful Monaro body was also dropped a couple of inches using a combination of King springs and Bilstein dampers, while a Whiteline front suspension tower brace was fitted to improve rigidity. Brakes are enhanced with slotted and drilled discs with EBC Green Stuff pads. A classy set of Simmons FR19s was also installed with 245/35 and 265/30 tyres. These wheels coordinate perfectly with the factory silver paint.

Shaun was very pleased with the improvement achieved with these relatively modest upgrades. The car was much more responsive and freer through the top-end – as evident by a 12.75 second ET. It now felt like a genuine performance car.

So how did the Magnuson/PWR blower come about, you ask?

Well, it was a case of being in the right place at the right time – namely, PowerTorque in Brisbane about a year and half ago...

PowerTorque was investigating the twin-screw blower kit jointly developed by Magnuson and PWR and Shaun put his hand up to receive one of the first kits on local shores. The kit (originally designed for the US-market Pontiac GTO) comprises a ‘5^th generation’ Eaton MP112 supercharger with integral bypass valve, replacement cast aluminium intake manifold with integrated intercooler, reprogrammed ECU and upgrade injectors.

So what makes this kit so impressive?

Well, it’s a highly efficient twin-screw design (giving instant boost pressure and a modest charge-air temperature increase), it incorporates a neat water-to-air intercooler system and the induction layout is nice an’ direct. The Magnuson/PWR kit incorporates a unique front entry to the supercharger – in contrast to most other positive displacement kits that require a tight induction route jammed between the rear of the blower and the firewall. The factory throttle body is bolted to the front of the blower and a heavy-duty plastic induction tube connects to the original airbox. Very neat.

Beneath the blower is a water-to-air heat exchanger that reduces post-compressor air temperatures. This exchanger teams with an electric water pump, a front-mounted aluminium radiator (as seen here) and a filler cap which is installed alongside the blower.

At the rear of the supercharger you’ll find its gear mechanism. These rear-mounted gears are driven by an input shaft that runs parallel to the main body of the blower. At the front of the input shaft is a pulley, which is belt driven from the crankshaft.

And all this nestles below the factory bonnet line. Impressive stuff.

The only change to the off-the-shelf Magnuson/PWR kit is a custom LS1 Edit tune using a MAP sensor instead of an airflow meter (as used in the standard kit).

Shaun says the twin-screw supercharger kit gives his Monaro magnificent on-road performance. Boost pressure comes on from about 1800 rpm and there’s approximately 5.5 psi held to redline. He admits it doesn’t make the same top-end power as some centrifugal blowers, but the on-road performance is quite comparable. Whatever the case, its current 284kW ATW output (on normal pump fuel) is hardly to be sneezed at...

"It’s far from an all-out racer," says Shaun who has run a 12.5 second quarter mile with the blower (just two-tenths faster than with the previous naturally aspirated set-up). Unfortunately, this time wasn’t helped by slip from the original clutch (which now has 47,000 hard kilometres behind it). A heavy-duty clutch will be fitted when the stocky is no longer serviceable and low 12s seem realistically within reach.

Visually, there’s been no need to add complexity to the Monaro’s clean lines – the immaculate silver paint and Simmons wheels speak for themselves. Shaun has de-badged the body to further emphasis the clean appearance.

The cabin trim is standard Series 1 Monaro all the way down to the Eurovox sound system and optional leather trim.

Although Shaun is extremely happy with the on-road performance of his Monaro, he says he’s considering an upgrade camshaft and increasing boost pressure – and maybe a fuel pump upgrade, if required.

This would surely be the icing on the cake or, more correctly, the polish on that silver bullet...

Contact/Thanks: PowerTorque +61 7 3881 2379 Shaun would also like to thank PowerTorque for their valuable help and expertise.