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Like most of us, Adelaide's Sam Scerri likes going fast, but everyone seems to have slightly different interpretations of how much speed is required to get the old adrenalin pumping at a rate which would put the ol' Horley Blue to shame. For some, 14 second's worth of travel time down 400m of blacktop quite aptly defines the term 'fast'. Sam, however, isn't quite pumped unless you cut that journey time in half. Seven-second trips down the quarter and then you're talking 'fast'! Then again, having been brought up on a diet of high-speed motorcycles Sam's expectations may be stightly higher than most strictly '4-wheel' enthusiasts.
This
bike freak holds two things very close to his heart. First up is his Castrol
Pro Stock motorcycle, (ex-Les Donnon Australian title-holding bike) and second
is the rather cool-looking gold VP V6 Commodore wagon that you see here.
Your average pro stock-riding quarter mile maniac would not exactly be a typical 'family' wagon-driving stereotype, especially when the wagon is used for enjoyment. The rationale is simple, though, Sam explained that the wagon's practicality on interstate drag-racing jaunts is the main reason the VP got the thumbs up when it came time to buy a car, Towing was also one of the main reasons for buying the V6. These, combined with the cavernous load capability, meant there really was no other choice, especially when you consider the 'cart-sprung' Falcons available at the time with leaf springs under the bum.
Speaking
of suspension, the VP wagon may look a bit pedestrian with standard ride height,
but a good dumping on its belly of about three inches improves the people mover's
appearance considerably. That is, of course, once each of the 16-inch 5-spoke
ROH alloys, wrapped in 235/50 liquorice, are stuffed under their respective
guards. The owner didn't go too overboard on the exterior, opting to simply
install an HSV-style front end and a discrete roof spoiler across the top edge
of the tailgate for good effect.
A fitter by trade, Sam is pretty handy at making things and, as such, needed
to use some of his crafting skills almost straight up after towing his first
load with the V6. The brakes on these cars aren't up to repeated abuse, especially
when the wagon is laden, making a brake upgrade mandatory to protect the valuable
cargo tied to the trailer, Now you or I would more than likely have opted for
a set of HSV Premium calipers and rotors on the front of the car, satisfied
with the extra stopping power that they provide. Not Sam, though. He had far
bigger and better ideas that revolved around fitting a set of higher performance
4-piston calipers and bigger rotors for the ultimate in braking performance.
Rather than go for the traditional aftermarket favourites like AP or Brembo, Sam simply went to the Jap wreckers and found a set of 300ZX Twin Turbo 4-spotters and their larger-vented rotors. After a few hours mucking around in the shed with his Tig welder and machinery, Sam soon produced some nice looking and supertough mounting brackets to hold the new hardware fn place, It sure is a surprise to look through the rim and see Nissan emblazoned on the calipers, but these puppies would stop a freight train in a jiffy!
It would be nice to have some more power for towing though, and with that thought in mind Sam opted for a 2.5-inch exhaust system complete with Pacemaker headers. He also replaced the original Delco computer with a programmable Haltech E6GM for some engine management noodling. The Haltach was selected as Sam wanted to make changes to the car over a period of time and didn't want to continually have the expense of re-adjusting the Delco Mem-Cal chip. It was all so easy, too, as the new computer simply plugged straight in and already contained a basic map for the V6 engine. Turbo Tune were entrusted with the job of calibrating the Haltach, and came up with a modest but respectable 90kW at the rear wheels.
This
was fine for awhile with the VP taking the back seat as drag racing commitments
kept Sam too busy to consider any more changes. Then the decision came to sell
the car, maybe to make way for a Corse Srada Extreme SiR or a (sin of all sins)
Nissan GTR. When you think about it, the VP was starting to get on a little,
being seven years old, but was still in immaculate condition. Then mother nature
intervened and the news came through that the family was about expand somewhat,
so all thoughts of disposing of the 'old faithful' got shelved, Instead, Sam
decided the VP would cop a few more modifications to make swift yet safe transport
for the new addition to the family.
A centrifugal supercharger was the answer here, as the idea of installing a blower onto the wagon - or any V6 for that matter - had always appealed to Sam. There was really no other option as a lot of his mates had already gone the blower route with their V8-powered cars and enjoyed phenomenal success. Rather than just any old supercharger, though, Sam made the decision to buy the single toughest, highest output blowar you could possibly get hold of. The result was a CAPA Vortech S-Trim combo the type that makes an easy 11psi plus, and usually on 5-litre engines.
Most people would also be pretty happy with running around the 8psi or 9psi
boost level as delivered by most superchargers, Again, not Sam, Instead he ordered
his Vorteeh geared to make a hefty and incredible 15-17psi, just to make sure
he has the wood on almost any V8 that was game enough to make the challenge
at a set of lights. There is some consternation, to say the least, as to whether
this is an entirely safe boost level for a standard engine. My experience suggests
no, but Sam didn't care as he wanted to explore the outer envelope of the engine's
strength and then rebuild it 
stronger
once it broke something.
A lot of the kit fitment was performed by Peter Hail from Tilbrook Auto & Dyno,
while Sam customised certain parts of the kit to meet his specifications. Rather
than the conventional CAPA under-guard K&N filter assembly, Sam fabricated his
own air-box arrangement to take advantage of his existing VS cold-air ducting.
You can see from the photographs that the air box has been carefully crafted from sheet aluminium and then tig-welded together precisely enough so that it will still accept the standard-size air filter. CAPA supplied 241b per hour fuel injectors, a 6-to 1 Vortech FMU (rising-rate fuel pressure regulator) and Vortech TREX fuel pump to supply enough total fuel for up to 350hp of engine demand. The blown VP engine needs nearly all of it to keep the air-fuel ratios safe, with the Haltech needing to be tuned over a longwinded 4-hour dyno session to accept the new high-boost application. At a lowly 3000rpm, this engine was already well into the 7psi boost area with the magical 15psi being reached just a handful of revs before the 5500rpm limiter.
Power figures, although acceptable, weren't great. We all expected a bit more, which led us on a hunt to find the culprit holding up the power output. A session with a back-pressure gauge in the performance 2.5inch exhaust system, soon showed that on full noise the engine was generating 12psi of back pressure! Bearing in mind that anything over 3psi is bad, you can see how much of a restriction this was.
A
twin catalytic converter, full stainless-steel twin 2.25-inch system was the
answer. It dropped the back-pressure figures down to almost nothing providing
the VP with a stronger top end and an even bigger requirement for topend fuelling.
After another dyno tuning session the biggest number generated by the VP was
a whopping 178kW at the rear wheels. This is amazing when you remember that
the car still has a dead-standard engine - that's a gain of almost 100 per cent,
even before Sam fits the custom intercooler that he is currently making. It
would only be a matter of time before an engine with this much output overcomes
the strength of its standard internals!
Some 5000 kilometres of hard driving down the track though, the VP still hasn't missed a beat, with not one nasty sign of engine wear or impending drama. In fact, regular compression tests show not one sign of degradation or wear, which frustrates us all greatly as we can't wait to see Sam's idea of building a tough engine!
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