XR Exterminator

An immaculate Ford AUII XR8 with a blower, cam and heads - and 320kW at the wheels!

Words by Michael Knowling, Pix by Julian Edgar

Click on pics to view larger images

At a glance...

  • Ford AUII XR8
  • CAPA Vortech blower kit
  • Trickflow heads and Ford Motorsport cam
  • Pushing the boundaries of stock pistons with 320kW ATW

For whatever reason, pre-BA Fords aren’t the most popular performance machines. Sure, they’re home-grown for Aussie conditions, roomy, tough and grunty, but the big Fords always play second fiddle to the Holden rival.

But to Grant Ward of Brisbane there’s nothing other than a Ford. Grant has owned an ED Falcon with bolt-on mods, an EL XR6 with similar tweaking and now this – a 320kW ATW Windsor 5.0 litre AUII XR8!

Grant says the step up to an AUII XR8 was a natural progression – the fact it’s a V8 and relatively late model made it the ideal machine to replace his much loved XR6. The performance and on-road feel of the XR8 is described by Grant as "fine" but, of course, old habits are hard to break. It wasn’t long before the XR8 was being transformed from standard bit by bit...

Initially, Grant’s mods were limited to aesthetics – Avanti 18 x 8.5 inch alloys with 265 and 255mm low profile Bridgestone S-03s complemented by superlow King springs. A set of Koni adjustable dampers and new polyurethane bushes were also included.

The next step was to unleash the Windsor V8’s grunt and give it a bit of a growl. A pair of Pacemaker Tri-Y headers was bolted to the heads and the rest of the system was fabricated by D&T Performance in Adelaide. The system employs twin high-flow cats, twin 2 ½ inch mandrel pipes leading into a single 2 ½ inch pipe over the axle. In light of the extra power that’s now generated, the rear section has since been replaced with a single 3 inch.

With the headers, exhaust and a K&N filter bunged in, Grant’s XR8 picked up around 5kW ATW for a total of 140kW at the wheels on Bob Romano’s Dyno Dynamics chassis dyno (Bob and his son, Chris, can be thanked for the majority of work on the car).

At this point Grant looked at his options and decided the next step should be to optimise the management system to suit the mechanical mods. A UniChip interceptor was fitted to the Ford loom and, once tuned, improved drivability along with an extra 10kW - one-fifty was seen at the wheels. This was quickly followed by a mild camshaft upgrade that gave a slight improvement at high revs without sacrificing idle quality or bottom-end torque.

With this sort of power output, the factory intake manifold becomes a considerable airflow restriction. There are various bolt-on replacement manifolds – but why bother with that approach when you can literally force air through the stock manifold?

Grant hunted down a new CAPA (Centrifugal Air Pumps Australia) Vortech V2 supercharger complete with all necessary brackets, belts, air intake, Bosch blow-off valve, upgrade fuel pump and water injection. Bob Romano and his team were handed the job of installation and the XR8 immediately responded with a considerable 230kW at the wheels. Note that this was achieved on 10 psi peak boost with the standard camshaft reinstalled.

With some mucking around ‘high flowing’ the injectors, sorting the pre-compressor intake and retuning the existing UniChip, power rose to 280kW ATW. Now we’re talkin’!

With these mods fresh under the bonnet, the standard clutch began slipping – understandably. Grant upgraded to a still-streetable heavy-duty clutch/steel flywheel combo along with a ‘ripper shifter’ on top of the standard T5 gearbox. At the squealing end you’ll find a shorter 3.73:1 Ford LSD. Oh, and at about this time a set of EBC Green Stuff brake pads and DBA discs were thrown on.

And Grant was pretty happy for the car to remain like this.

For a while.

The camshaft and cylinder heads were the next area of improvement. Trickflow aluminium bolt-on heads were fitted to the standard block along with the associated rocker arms, pushrods, valves and valve springs. A genuine ‘B303’ Ford Motorsport camshaft and timing chain set also went in along with an upgrade fuel system – namely, bigger injectors, a Bosch Motorsport pump and Vortech progressively rising rate fuel pressure regulator. Interestingly, Grant also installed Phenolic manifold insulators to help prevent heat soak issues.

With no extra boost pressure (still 10 psi peak) Grant’s XR8 has delivered 320kW at the wheels on the Romano chassis dyno. What’s more, Grant says it’s anything but a pig – it gets driven every day in all temperatures, fills with fuel at the local servo and has performed problem-free. The only hiccup was the supplied pre-compressor pipe was ‘sucked in’ at high loads; this pipe has since been replaced with a custom set-up. The Romano’s also elected to switch to higher quality blower lubrication fittings and silicone pipes.

Both Grant and the Romanos agree the car is pushing the limits of the stock engine internals. Without an intercooler to reduce intake air temperature, there’s always the risk of detonation, but some careful tuning and in-house modification of the CAPA water injection system prevent undesirable combustion behaviour.

So without any bottom-end strengthening, the car has ran a best quarter mile time of 12.6 seconds at 115 mph. Note that this was using the street Bridgestones which Grant says are great – but they’re a long way off slicks. With more grip, a low 12 seems likely.

But isn’t it time to upgrade to a BA Ford?

Well, in all probability he’ll keep this beast – the cost of buying a new car with similar performance would be astronomical. Instead, Grant wouldn’t mind adding an intercooler or maybe a 6 speed – or maybe a stroker crank.

Whatever way he goes, you know it’ll be Game On against anyone that pulls alongside in a ‘hot’ Holden....

Contact/Thanks:

Bob Romano Performance                                   +61 7 3395 8255
                                                                                    www.bobromano.com.au

Grant would like to thank Bob and Chris Romano and the rest of the team.

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