Stretched custom Ducati 749 turbo dragster

This custom Ducati 749 dragster is a labour of love by Wayne Patterson and his son Todd. Words: Mick Withers, Photography: Dave Earp

When you open your shed door and look at the Ducati 749 you built with your son, you’ve got to feel a sense of pride. Knowing that it’s the most powerful two-valve Ducati on the planet as well as being the quickest of the breed over a standing quarter mile has to make you smile. But – where do you go next?

This is the predicament that Bunbury Ducati owner Wayne Patterson, or Patto as he’s universally known, found himself in. He looked through the then-current range of new Ducatis and found his eye drawn back to the 749/999 models.

“It was a very aerodynamic shape and quite modern look,” said Patto. “It had to be a Ducati and this time with a four-valve engine. We chose a 749 because the smaller capacity had more material around the barrels and fitted into a drag racing class that suited us better.”

With the decision made, Patto started working the phones and found that Craig McMartin had a frame and incomplete engine that he’d let go, “This was before engines and parts were easily obtainable on the Internet,” explained Patto. “We then bought the parts we needed to build a complete bike.” Sounds very simple when you read it…

This was all in 2006 and Ducati hadn’t released the 1098 so the 749/999 was the latest and greatest offering from Bologna. To get the project moving, Patto handed it all over to Todd, workshop manager at Bunbury Ducati and the boss’s son. “He was my apprentice and now he checks my work!” laughed Patto with more than a hint of pride.

Todd started by sourcing an Ohlins front-end that left the Ducati factory attached to a Paul Smart Replica. Bolted to the 749 frame and fitted with a 749R front wheel, that gave them a starting point.

At the other end of the workbench, a Mickey Thompson slick was mounted on a six-inch-wide forged magnesium ex-superbike wheel and placed in rough position. Filling in the gap required a swingarm so with the main horizontal arms made to correct length, Todd mocked up and designed the swingarm and supports out of cardboard that bolted to the unmodified frame and placed the titanium rear axle 200mm further away from the countershaft than the original.

The frame, front-end, wheels and cut-out alloy panels for bracing and rigidity were delivered to Gavin Forbes from FME Engineering Services who fabbed the swingarm and then trued the whole assembly after finding and rectifying a slight tweak in the original frame.

The swingarm was designed to maintain the appearance of a stock-type swingarm rather than the normal triangulated drag racing assembly. At a quick glance, it looks like the swing arm will still pivot upwards, yet it is fixed in position.

While work was rolling along happily on the chassis, Todd could have a closer look at the incomplete engine Patto delivered into his care. The camshafts of unknown origin were fitted with lightweight alloy pulleys – it was suspected that this was not a stock engine.

In anticipation of boost and increased horsepower, Todd got in touch with Crower and ordered a set of custom titanium H-beam rods. The original pistons were fine for their intended use but for this build-up, a set of custom forged pistons was ordered from Arias.

With a ceramic-coated crown to keep the boost in the combustion chamber without collapsing, the ring pack was also placed lower on the piston away from the heat of combustion. FME knocked up a set of spacers to keep the pistons centred on the gudgeon pins.

“The gudgeon pins are so strong,” added Patto with a smile, “that the bloke from Arias told us that even if there was nothing left of this engine due to a blowup, we’d be able to re-use the gudgeon pins!”

Once the basic rotating assembly was sorted, the crank was removed and handed over to Justin Klashorst from Pro-Twin to be lightened and balanced. During the engine’s re-assembly, Todd removed the stepped 8 to 10mm head studs and replaced them with a set of custom 10mm items that he reckons look like Artline textas.

With the engine back in one piece, Todd then got to degree and dial the cams in. The adjustable pulleys were not slotted but had a series of boltholes to achieve desired cam timing. The first head took a day but the second only took half a day. It was worth it though with the four cams now within half a degree of the desired lobe centres.

The engine was re-inserted in the frame so that work could get started on the plenum chamber and associated turbo plumbing. After hanging the Garrett GT25 ball bearing turbo off wire hooks and standing back and looking at it, the decision was made to rear-mount the turbo up under the rear seat cowl.

Pieces of 54mm-diameter steel tubing carried the exhaust gas from each cylinder to the exhaust wheel of the turbo. Once it had done its work, the exhaust was then directed to atmosphere through a short dump pipe that replicated the standard under-seat muffler.

The cold side of the turbo pushed the compressed air into the plenum chamber through a single 65mm butterfly and from there into the engine via a pair of Intake Express velocity stacks and 916SP twin-injector throttle bodies that have had the butterflies and standard injectors removed. Four Indy Blue injectors have been fitted in place of the stockers but the butterflies never made it back on board.

An anodised aluminium fuel tank holds the four litres of methanol that feeds the engine-driven Aeromotive mechanical fuel pump. Providing fuel pressure is a boost-referenced regulator before the fuel flows to each injector and awaits entry to the engine. Controlling the Indy Blue injectors is an Australian-made MoTeC M400 that was tuned by Todd and Glen Baker from Autosport Electronics. The M400 also controls the MoTeC boost controller.

Spark is ably handled and controlled by an Australian-made M&W Pro Drag 2 ignition, a set of MoTeC ignition coils and NGK iridium plugs. All of this, along with the MoTeC, is powered by a lithium polymer battery pack that weighs just 800grams. A big weight-saving compared to the monster 4.5kg stocker.

Transferring torque from the crankshaft is a stock 749 aluminium clutch basket filled with sintered clutch plates from Ducati Performance Parts. Crowning the clutch basket is a lock-up hat that was made by drag racing legend Ray Easson for Patto’s turbocharged 900SS.

Inside the ceramic-coated crankcases is an original 749 six-speed transmission that has been undercut and carefully set-up to make sure that the gear selected by the air-shifter remains selected. The chain is about half-a-metre longer than stock to suit the 1650mm wheelbase as well as the 15 and 45-teeth sprockets now fitted, “We use all six gears on a run!”

From the sounds of it, the build progressed at a steady rate until three weeks before the start of the 2010/2011 drag racing season at the Perth Motorplex. At that stage, the engine build was yet to be finished, the wiring was non-existent and final assembly and tuning were just a couple of points to aim for. The workshop was closed to outside work and 15-hour working days became the norm.

Before the first fire-up could happen the plumbing for the fuel system as well as the wiring for the MoTeC all had to be installed. This process almost made Todd and Patto cry as they watched the weight being added. To help offset the weight gain, $1000 worth of titanium bolts saved a whole kilogram…

With fresh batteries in the starter trolley, the remote starter was plugged into the left-hand side of the crank and the engine wound over at 4000 rpm to get all of the fluids circulating before the ignition switch (that saw service in a B-52 bomber before it was fitted with the shiny red safety cover and installed) was moved to the on position and the Duke fired right up and idled away on the Bunbury Ducati in-house Dynojet dyno. Todd and Glen Baker made alterations to the baseline to get a good starting point for the first trip down track.

From the outset, this Ducati was always intended to look like a Ducati factory superbike. With the unmodified frame, this was a fairly straightforward deal and a full set of Ducati Performance carbon-fibre panels was ordered.

The only non-genuine part is the rear guard that Brett Hilton crafted out of carbon-fibre. Aaron Mathews was entrusted with the task of applying lots of coats of Ducati Red to all of the bodywork before the genuine and non-genuine decals were applied and covered with coats of clear.

At 6am after an all-nighter, the painted fairings were fitted for the first time and the Ducati was loaded in the trailer and taken out to the Motorplex for the first meeting of the new season. They made it with hours to spare. The finished job is pure magic and it does look like a factory superbike but longer and lower.

It’d be great to report that the first outing was all love and happiness but we sort of can’t. There was no lockup on the clutch and the gearing was very tall – the rear sprocket was a 36-tooth item compared to the 45-tooth circular saw blade now fitted.

Patto was launching, or more accurately, riding it off the line like a street bike but he ran 10.4s and the brand-new bike never missed a beat. The next four meetings were spent sorting out the clutch and gearing as well as modifying the swingarm to take the bigger rear sprocket.

The first turbo drama happened at the sixth meeting and turned out to be a collapsed bearing so the turbo was despatched 170km north to Perth for a rebuild. No biggie, you expect teething problems.

After the second turbo rebuild, Todd found that the internal wastegate was bending due to the backfiring of the anti-lag system. A 40mm external wastegate cured that but then the third turbo rebuild was diagnosed by Todd when he heard that too-familiar collapsing bearing noise.

It turned out that even though the original 54mm diameter headers had been welded and purged correctly when modified, small welding dags were floating around in the headers from the original manufacturer.

In a normal standard application, those little dags would have just been blown out the back without any problem at all. Unfortunately, when they hit the turbo exhaust wheel, it was like someone kicked a soccer ball in and stopped the wheels from spinning.

A new set of headers was called for but the diameter was reduced to 38mm to increase the velocity of the exhaust pulse hitting the turbo wheel. More importantly, the decision was made to move the turbo down underneath the engine.

This was designed, fabricated and tuned in a matter of days but Patto still had to drive a 600km round-trip to pick up his turbo that a freight company had sent 600km in the wrong direction… He drove halfway and so did the courier.

On-track performances improved immediately and at the very last meeting of the season, he recorded an 8.903 against the DD/CBI index of 8.900. This was with 22lb of boost that allows the red Ducati to make a dyno-proven 222.26 horsepower at 9000rpm and at an all-up weight of 265kg, still 20kg over-weight for the class,

“We hope to get into the low eights,” said Patto. “In our first season with the bike, we made it transform rapidly. We fully remade the turbo system between rounds last year, so it was a very busy time in the fabrication department.

“Also, we’re still learning to make the most of all the technology that the bike already has installed. Next season we hope to not be making parts and inventing systems but just fine tuning what we have already.”

A weight-loss programme is already planned but the options are getting limited when nearly everything is already titanium or carbon-fibre. Patto mentioned that they’ve still got a few ideas up their collective sleeves. Maybe it involves unobtainium.

SWITCHES AND STUFF

The ignition switch started life in a B52 bomber but that’s only one part of the bits that make up the controls. The Power Commander map switch turns the M&W Pro Drag 2 ignition on. To change gears, Patto pushes the Dynojet quickshifter button. There are two lanyards fitted: one turns the bike off in an accident and the other prevents Patto from shifting gears in the burnout. So far, Todd has always removed the correct one on the startline. So far…

MOTEC BOOST CONTROLLER

A MoTeC electronic boost controller controls the maximum boost level. This clever unit bleeds boost pressure away from the external wastegate allowing for boost control and higher than standard levels of boost and fun.

The boost is also gear related, so they can have six different boost levels, or one boost setting per gear.

Specifications: Custom Ducati 749 Dragster

ENGINE: 2005 Ducati, 10.5:1 compression, Garrett GT25 ball bearing turbocharger, external 40mm wastegate, unidentified camshafts, custom Arias forged pistons, 10mm head studs, Crower H-beam titanium conrods, lightened and balanced crankshaft, Davies Craig electric water pump, custom radiator and hoses, M&W Pro Drag 2 ignition, MoTeC coils, NGK iridium spark plugs, MoTeC M400 ecu, custom plenum chamber, 916SP twin injector throttle bodies, Indy Blue injectors, 15/45T gearing, chain final drive

CHASSIS: 2005 Ducati 749 unmodified chrome-moly frame, swingarm designed by Todd and built by FME, Paul Smart Replica forks, 3.50 X 17 and 6.00 X 17 Marchesini wheels, Moto Master rotors, Brembo master cylinders and calipers, Hel Performance braided lines

BODYWORK: Ducati Performance carbon-fibre bodywork, rear guard by Brett Hilton, Paul Smart Replica front-end, Pazzo levers, B52 ignition switch.

PERFORMANCE: 222.26 horsepower at 9000rpm.

SPECIAL THANKS: Todd Patterson at Bunbury Dyno, ROPS Australia, Silkolene, Competition and Industrial Coatings, Geoff Curtin, Gavin Forbes at FME, Mike Walters, Sean Arthur at Adrenalin Performance, Glen Baker at Autosport Electronics, Pro Twin Australia, Bernie McCormack, Michael Macri, Paul Whelan, Neil Anderson at Pro-Flo Motorcycles, Aaron Mathews, Claude, Brett Hilton, Ben Okane, Grant at Per4Manz Turbo, George Johnson, Brook Henry and sorry for those that I have missed. Oh yeah and Glenda the missus.