AutoSpeed - Pure Class

This article was first published in March 2001.

Just once in a while we come across a feature car that's just so good, so innovative, so inspiring and so clean that all we can do is gasp. Sven Djuve's XF Falcon ute is one of those rare cars that's a heap more than just the sum of its parts - and even just its parts are pretty impressive. The twin supercharged V8, in-cabin height-adjustable pneumatic suspension, gas-strut supported flat tray cover, carbon fibre centre console - it's all there and it's all innovative. But it's when you look closely that you start to realise the magnitude of what confronts you. Take the ex-Toyota superchargers, f'rinstance. Yep, we too have seen Toyota blowers bolted to engines - but we've never see intake adaptors turned and milled from solid billets of alloy, shaped internally for maximum airflow (the wall thickness is as thin as 2mm!) and lovingly formed externally so that the bolts are easily accessed, the adaptor looks good, and it all works like it's from the hands of an OEM. Or look at the intake manifold. It started as an Edelbrock design, but the machined adaptor that sits on the highly modified intake is all from the hand of Sven. Or those nose extensions on the blowers - nope they aren't an off the shelf part; again they were custom machined from billet. It'll surprise no one that Sven's day job is as a design engineer...

Lift the bonnet of this Falcon and the first thing that confronts you is the engine. The use of twin superchargers looks great, but in fact Sven says with a smile that they were selected primarily because of their low cost - just $350 each. In fact, Sven bought a few more as spares - and another to pull apart - and his bulk-buying power got them down as low as $295! Originally fitted to the Toyota 1G-GZE 2-litre six, the transplant to a 5-litre V8 necessitated both the use of dual units, and also that they be spun at 1.5 times engine speed if the required 12 psi boost was to be realised. In fact, initially they were rotated at 1.2 times crank speed, but the resulting 3-psi boost just wasn't enough....

The blowers use a straight Roots design, with the all-alloy rotors Teflon-coated and running a cold clearance of about 0.5mm. Sven makes the point that these are not good blowers for DIY rebuilds - it's easy to get the timing wrong (ie the rotors then run into each other!) and the bearings are held into place with a nylon insert that needs to be broken to allow bearing removal. And when you do get them out, no one has ever heard of the bearing size, let alone having a replacement on the shelf!

The twin blowers are driven through a toothed Gilmer belt drive, 50mm wide and with a half-inch pitch. They turn pulleys attached to high tensile steel shafts that are splined to match the original blower steel input shafts, and spin within those superb machined-from-billet alloy nose extensions. As with the whole installation, Sven ran up some CAD drawings of the extensions before allowing a cutting tool to touch the alloy, but even so, making just these bits took two full weekends of labour. The lower pulley - of course another owner-built part - also pulses the crank trigger for the Haltech IG-4 programmable ignition system.

The V8 is a classic 302 Cleveland, and it's largely standard - yes, even the pistons and comp ratio. When the engine was rebuilt, the 2V heads were cleaned up and then an Ivan Tighe cam was slotted into place, but that's about it. Bolted to the back of the V8 is a C4 auto, equipped with a shift kit and 2800 rpm stall converter. Also attached via cable linkage is a TE Magna shifter - one of the many tricky bits that looks totally integrated.

Fuel comes from an LPG system, using twin OHG mixers. These exotic bits of gear use four needles within each mixer, allowing extensive adjustments. However, in this case they "worked out of the box" though the perfectionist owner would still like to spend some time on the dyno with a good gas analyser to perform some final fine-tuning. Following the mixers are twin XE throttle bodies - but they're hard to recognise because of the superb throttle cable adaptors that have been machined up. As Sven says, "I don't think that there's much under the bonnet that was store bought." The gas converters are also from OHG and required the fitment of lighter springs. More attention to detail can be seen in the twin flat panel airfilters located just behind the headlights. Housed in alloy frames, a huge amount of effort went into a design that would still allow (relatively) easy filter changes, breath in only cold air, and have minimal pressure loss. At the other end of the engine, the exhaust gases exit through HPC-coated Genie extractors, followed by a twin 2½-inch system.

Originally the extractors were naked, but a problem soon arose. Because the car is so low (or can get so low - more on the adjustable suspension in a minute) Sven has fitted a full engine undertray. Made from 8mm marine ply with steel rubbing strips, the tray stops the sumps being knocked off "most days of the week" but its fitment had an unexpected negative - engine temps rose enormously. In fact, even with the custom, huge, 4-row radiator and twin 14-inch electric fans, the needle was always climbing. Sven figured this was because the exit airflow from the rad was being trapped, so took to the bonnet in the big way. Huge louvres were fitted, with each vane made from steel and welded into a frame that was then in turn welded into the bonnet. What loss of bonnet rigidity? The louvres are made so beautifully that most see them as just a cosmetic addition, but they sure aren't. (And the bonnet bulges needed to clear the blowers and their drive system? Again made from steel, pressed into shape with tool made by Sven and then with the bulges also welded into place.) And the extractor coating? To make doubly sure that temps were not a prob Sven had them coated with an insulating ceramic layer, a process that he says gave excellent results. And - nothing like killing a problem totally stone-dead - a massive engine oil cooler was also fitted in the left-hand guard. Nope, overheating is no longer an issue!

As you can see in the photos, Sven wasn't content just to spend time on the driveline. The ute features a twin headlight conversion - in fact, Sven's second job sees him making twin headlight adaptors not only for Falcon utes, but also for Commodores and WRXs. As you'd by now expect, these are also nice bits of gear, with proper headlight adjustment retained, a wiring harness provided that plugs straight into the factory loom, and the use of all the original bodywork bolt-holes. Moving down the car, the doors are from an LTD and feature that car's central locking and door handle-triggered interior lighting switch-on. Further back there's a custom tailgate that integrates the number plate and sits above a custom beaver panel that is made from a folded steel section. Note the square hole in the new lower panel - the one with superb rolled edges? You wouldn't know it until you were told, but a tow-bar fits into that recess!

The flat tray cover is made from a steel frame with a fibreglass skin bonded to it, resulting in a relatively light (about 30kg) and very stiff cover. It's supported on twin gas struts and locks down into place with what were previously bonnet catches. The catches can be solenoid-released by pressing a hidden pushbutton located above the number plate - but only when the ignition is on. Testament again to the incredible attention to detail exhibited throughout the car is the fact that there's also a way of getting the cover open even if there's a major electrical failure or one of the solenoids turns feet-up. If you remove a taillight, a pull cable is revealed - it's the emergency release. This guy doesn't just do beautiful workmanship, he thinks it r-i-g-h-t through as well!

Lift the rear cover and you'll find underneath a carpeted tray; lift another hatch behind the rear window and you'll look down at a powerful and lightweight Odyssey battery (which Sven swears by), an air compressor and pressure tank with attached plastic lines and control system, and.... A what? What's the air compressor doing there? Remember the air adjustable suspension? Well, this isn't the kind that you go along to the servo to put some more air in the shocks when you're towing a caravan. Nope, this is the sort where Sven presses a dash-mounted control and can wind the front and the back of the car up and down as he wants!

Inside the front suspension there's a complex collection of parts - starting with 4-inch lowered The Rod Shop drop spindles, followed by a shorter than standard spring. Then there's a mixture of an airbag, Gabriel damper, GT Falcon damper and a whole host of Sven ingenuity and workmanship. Suffice to say, the front suspension can be moved up and down over a 2-inch range, while the car can still be street driven without any problems at all. At the back, the leaf springs have been substantially weakened, with air shocks used to provide both much of the springing and allow the altering of the ride height. Keeping the axle tamed when the torque hits the diff are two longitudinal axle-locating links - before these were fitted things used to get really ugly! This brief description skirts a lot of the detail - we could easily write a full article on just the amazing suspension, from its custom turned front upper damper mounts to the logic of the control system, which even includes dash-mounted flashing red warning LEDs when the air pressure is low, and three pressure settings that can be read off on a centre console mounted gauge!

Hiding behind the front 16 x 8 ROH ZS wheels are drilled and slotted Ford discs being gripped by re-located HQ Holden calipers, while at the rear the 4-pinion 3.27 LSD'd diff drives discs that are standard but for their drilling and slotting. Tyres are 225/50 Falken ZE-502 on the front and wider 255's at the back.

So how fast is this thing? Though built primarily to cruise - there's an Alpine V12-power sound system that incorporates a 10-inch sub and Alpine 6x9's to listen to - Sven has put it to the stopwatch test. With engaging honesty he tells the 0-100 time as a relatively slow 6.8 seconds, but talks of the massive wheelspin that's happening everywhere during the acceleration event. "Just how do people with two wheel drive cars get such quick 0-100 times?" he asks.

Thing is Sven, they don't normally have a 5 litre V8 that is boosting to 15 psi from idle, do they...

Pure Class

This is just fantastic....

by Julian Edgar

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