Bad Mama Munro

In recent articles we’ve shown some very different approaches to LS1 performance. First was Andrew McKellar’s 445hp ATW SS wagon with a supercharger kit (see Logical LS1). Second was C&V Performance’s nitrous assisted VY, which – with a 10.35 second pass under its belt - is currently the fastest LS1 in Australia (see SV8 Record Smasher). Third was Criso’s 10.7-second ute running ram-tube induction and a 383ci stroker kit (see Pure LS1 Performance).

Well, here’s another approach that achieves low 11-second performance with the standard 5.7-litre capacity, no supercharger and no gas. This is a traditional-style grunter!

Lumpy and groggy at idle, this car is not for those that put too much value in NVH. And fuel economy? “I’ve never bothered with it,” says the owner, Allen Hailey. Kilowatts come first and foremost here – but within one important boundary. Allen wants to see how fast he can go with a stock bottom-end.

So far, we’re talking 11.3-second performance at 122 mph – and there’s more to come!

This journey started when, having stepped up from a 12-second Holden VT SS, Allen bought himself a CV8 Monaro fresh off the showroom floor. “It was a nice car,” he says “but it felt really slow compared to my VT and I didn’t think it sounded any good.”

Not surprisingly, the car was modified within the first 1000 kilometres.

The first mods were executed with a view to achieving b-i-g horsepower down the track. The exhaust was swapped to a twin 2½-inch system featuring an X-pipe, CAPA extractors and high-flow cats. At this stage, Allen also made up his own induction system that eliminated the airbox and ran straight into the mouth of the throttle body. No filter.

Satisfied that exhaust and intake restriction were minimal, Allen approached Sam’s Performance in Sydney for a tried-and-proven head and camshaft upgrade. The alloy 2-valve heads spent some time under the die grinder, larger valves were inserted and a mild-ish cam was used first-up – there wasn’t much point going for something wild with the standard intake manifold in place.

To make the most of these mods, Sam’s Performance brought out the LS1 Edit program to change the factory ECU’s way of thinking. The airflow meter was also discarded in preference of a MAF-less tune (the engine now runs off a MAP sensor).

LS1 enthusiasts know a combo like this is generally good for approximately 350hp at the wheels. Hmmm. Powerful, but not powerful enough...

In the next visit to Sam’s Performance the stock intake manifold was flung and one of Sam’s sexy ram-tube induction set-ups was bolted on. Ahh, the crowning glory. These ram-tubes are tuned-length and feature individual 50mm throttle bodies – oh, and a hole also needs to be put through the bonnet.

Now that there was virtually no pressure loss through the entire intake system, the previously installed cam was replaced by a bumpstik that’s, well, as big as you could possibly go in a car that gets driven on the street.

The fuel system was also improved with a Bosch Motorsport pump, surge tank, bigger injectors and an adjustable pressure regulator.

And there are a couple of other mods to be found under that chopped bonnet.

To help keep the engine running near optimum temperature before staging, Allen has fitted a Mood Motorsport custom aluminium radiator. The standard electric fans are retained and these are manually activated before each pass.

Note that, apart from the cam and head mods, the engine is 100 percent stock internally. Despite this, the engine has muscled out 440hp on the rollers of Sam’s Performance’s Dyno Dynamics chassis dyno. Four-forty at the wheels? Can’t complain about that!

Backing the lumpy LS1 is the standard 6-speed ‘box – pretty impressive considering the flogging it has received. As you’d expect, however, the clutch has been upgraded to a 5-puck semi-brass button unit.

Out back is where there have been most of the problems. After snapping a couple of standard axles and unis, Allen went for the ‘indestructible’ alloy 9-inch job, which is fast becoming popular. With a 4.11:1 centre, Allen can now feel confident launching with whatever technique he chooses.

Slick tyres are a requirement if you want any real indication of the car’s performance and with these fitted, Allen launches the Monaro at around 5500 rpm. That's 1500 rpm shy of the programmed rev limit. To date, his best quarter mile time (recorded at the wonderful new West Sydney dragstrip) is an 11.3 at 122 mph. And Allen is confident of dipping into the high 10s with essentially the same set-up...

Look inside the cabin and you’ll see nothing has been removed to help shave off slithers of time. The full leather Monaro trim – in addition to a Pioneer double-DIN sound system – means there’s performance without poverty.

Outside it’s a similar story. The panels are all factory Monaro, the only changes being 19-inch HSV GTS rims for street duties and slicks for the track. Incidentally, the 245-width street tyres turn to jelly when those eight individual throttles are opened. As you have probably noticed, the ride height has also been brought down thanks to King springs (on adjustable platforms at the front) together with Koni dampers. Step on the brake pedal and DBA Greenstuff pads bite into a set of DBA slotted discs.

LS1 owners will be interested to hear that Allen has had not a single problem with the vehicle, apart from those rear-end failures. “They’re certainly not strong in the rear,” says Allen. “I even broke an axle in my LS1 ute, which is pretty stock and uses a standard clutch.” You should also be aware that this is a pretty rumpety engine – if you want to avoid police attention it’s probably not for you.

And, yes, there’s even more shake to come...

Did we tell you ‘bout Allen’s new stroker motor that’s in the build???

Contact: Sam’s Performance +61 2 9772 3105