All too often we see people spending disproportionate amounts of cash on auto cosmetics. It's all just a fashion show to them. But, certainly, Melbourne's Rob Velkovski doesn't suffer from this affliction - he's a dedicated grunt man through-and-through.
But that doesn't mean he simply wastes his cash on the mechanical side of things. No way. His VL 0747 shows how it really is possible to pull 10-second quarters from a VL turbo without wiggin' out with a full rebuild and an expensive ECU...
Bought from a mate about two and a half years ago, Rob's VL came with a brace of mods already performed by Johnson's Performance Centre. However, when it first arrived at his place, the package was only "half done" and running a mere 11.8 second quarter mile. It possessed a T04 turbo (complete with a 32mm Turbonetics external wastegate), 3-inch exhaust (including a cat, resonator and muffler), Finer Filter pod (thats's a dummy factory airbox), a XF Ford throttle body, Skyline GT-R based air-to-air intercooler and a Porsche main fuel pump. The SOHC 2 valves per cylinder head had also been ported for some extra flow and equipped with re-tensioned valve springs. Oh, and a 3.9:1 ratio LS differential was roped under the rear for a little bit more go.
Rob says "it had a fair bit of pull" when he first took ownership, but (some say inevitably) it wasn't long before the RB30 was running quite sick. Knowing that something major was up, Rob pulled the sump and head off and slipped out the slugs for a closer inspection. Hmm, it looked like one ring land has a severe case of discontinuity... eek. Accordingly, another replacement piston was chased down, new 'rod bearings were purchased and the whole lot was promptly bolted back together. Good as new (well almost!).
Again (inevitably) it wasn't long before Rob got the itch to get his Exec on the pace of a couple of other mega-quick VLs prowling the area. The job called for JPC to come to the party again with a "baby" cam, 45mm PSR external wastegate (which gave about another 12kW on its own), a ported exhaust manifold, an oil breather catch can and a Carter lift pump (that feeds into a custom surge tank). The driveline was then improved with a TCE 4000 rpm hi-stall converter and a manually shifted and fully tricked Trimatic transmission (all the work of Raceglide). Of course, by this stage, the 4-speed Jatco trans that the car originally came with the car was starting to slip like a pair of socks on a polished marble floor.
In terms of working out fuelling requirements, Rob's car is very different to most VLs running in the 10s ("most" - like, there's heaps of them!). Amazingly, his VL uses the standard management system - yep, that's right a stocker computer! He doesn't see an aftermarket ECU as such a huge necessity. This move means Rob's car maintains full accessory control (ie idle speed compensations etc), factory smooth cruise economy - and it drives so well you'd hand the keys to Grandma (with the boost turned down, of course!). The only changes made to the factory ECU is a raised rev limit (to 7000 rpm) and the relocation of the factory Bosch airflow meter to between the intercooler and the throttle (which apparently improves intake airflow). Not surprisingly, more fuel is needed, so another set of six Bosch 036 injectors are hidden underneath the intake manifold (the extra injector you can see is just a dummy). Mark (of JPC) says these six extra squirters are progressively brought into play by a MicroTech Microfueler at around 11 psi boost.
On the JPC in-house chassis dyno, the white Commy has very recently proven its combination by stomping out a massive 308kW at around 25 psi boost (with Avgas). Notice - that's kilowatts at the wheels! Mark comments that - despite not having programmable management - it's been set up relatively safely too. "We run it fairly rich at about a 11:1 air-fuel ratio because it still runs the factory pistons," he tells. Running that very same boost pressure at the drag strip (along with G60 M&H slicks), Rob's drive-it-there-and-back VL has run an official 10.9 at 126 mph.... However, the best he can get out of a set of 225 street tyres (on those 16 inch Walkinshaw rims) is a 12.3 at 119 mph - with a lot of rubber burning along the way! That's no shock though. Apparently this car can generate a wild amount of wheelspin even at 120 km/h!
Yep, you could say this car is fast. But - for Rob - it's not quite fast enough. He plans to get his 'L going quicker yet - and, of course, that's still with the factory management system wired in place. Boy, wouldn't you be jacked off if you'd just went out and bought a programmable ECU for your VLT Commodore?
Jeez...
Contacts/Thanks to:
JPC (Johnson's Performance Centre)
+61 3 9465 2244
RaceMatics
+61 3 9335 1011
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