Since the LS1 5.7 litre V8 (aka Gen 3) was introduced to the Holden/HSV
line-up, traditional style V8 performance has been lifted to a whole new level.
Sure, the earlier VT 5.0 litre V8 made all the right noises – but the LS1 5.7
makes the right noises and makes some mumbo.
Here we take a look at the ‘big picture’ of factory LS1s in
Australia.
LS1 Running Changes
The US-sourced LS1 was introduced to Australia in mid 1999, putting an end to
the locally-designed 5.0 litre V8.
The all-alloy pushrod V8 features a deep skirt block with 6 cross-bolted main
bearing caps and cast-in iron cylinder liners. A nodular iron crankshaft, forged
rods and cast eutectic aluminium pistons are employed. The compression ratio is
a relatively high 10.0:1.
LS1 cylinder heads are said to offer superior airflow and more even
cylinder-to-cylinder distribution compared to the LT1 predecessor (which was
sold in America). The valve angle is set 15 degrees from vertical and a hollow
camshaft and roller followers are used. A nylon composite intake manifold,
single throttle body and a 74mm hot-wire airflow meter completes the air intake.
Engine management is by a sophisticated 32-bit PCM (Powertrain Control Module) delivering sequential
injection and control of 8 ignition coils. The fuel cut-off is programmed at
6200 rpm.
Appearing in the 1999 VT Series 2 Commodore - and its contemporary Statesman
and Caprice brothers - the first LS1s were factory listed at 220kW at 5200 rpm and
446Nm at 4400 rpm.
Barely a year after the introduction of the LS1 VT2, the VX series was
released in August 2000. VX LS1s feature an improved LS6 inlet manifold, new
injectors and a remapped PCM. These changes increase power by 5kW to 225kW.
Power remained unaltered through the 2001 VXII series (during which the new
Monaro was added to the line-up).
The sharper looking VY series was launched in late 2002 bringing a high
performance twin exhaust system for the SS, Monaro and newly released SV8
models; this improves power by 10kW for a total of 235kW.
Similar exhaust upgrades were adopted in 2003 for the Statesman and
ground-breaking new Adventra; these share a 235kW rating. But even more
impressive is the 2003 Caprice, which is bumped up to 245kW with a dual exhaust
and low restriction air intake. Commercial-based LS1 Holdens – the Crewman, ute
and one tonner - make only 225kW.
The late 2003 VYII update brought very minor detail changes and a retune
boosting the SS, SV8 and Monaro to 245kW. The Berlina, Calais, ute, one-tonner
and Crewman were boosted to 235kW using the same enhancements.
The latest ‘04/’05 VZ series brings electronic throttle control, a revised
exhaust, new PCM calibration and a fatter induction system (including a larger
airflow meter). This is said to reduce intake restriction by 25 percent compared
to the VYII.
The VZ Commodore SS, SV8, LX8 Adventra and Caprice gain 5kW from these
improvements (for a total of 250kW) and the Statesman picks up 10kW (for a total
of 245kW). Curiously, the VZ Berlina, Calais and Crewman V8s remain at
235kW.
The latest Monaro incorporates across-the-range VZ upgrades as well as a
revised cam profile, a dual split exhaust and PULP-specific mapping – the result
is 260kW at 5600 rpm and a magic 500Nm at 4000 rpm.
This is the most powerful Holden manufactured.
|
Camshafts?
Note that, although there are no changes detailed in Holden press release
literature, we’re told that there were several different cam profiles used since
the VT2 LS1. The VT2 cam was particularly conservative and each profile since
then has been more aggressive.
|
HSV Upgrades
HSV (Holden Special Vehicles) are responsible for developing the most
powerful factory-backed LS1s sold in Australia.
HSV’s first effort with the LS1 appeared in the 1999 Senator, Clubsport and
long wheelbase Grange. The HSV tuned engine uses a ram-air cold induction
set-up, stainless steel extractors, high-flow cats and exhaust and a remap
optimised for PULP. Note that the new exhaust is said to cause only 0.22 Bar
(3.2 psi) backpressure at full power. Full power is 250kW and there’s up to
473Nm of torque – a tidy gain over the contemporary Holden models, but the early
LS1 intake manifold holds things back.
In 2000, HSV models received the improved inlet manifold and injector
configuration introduced to VX LS1 range. Tuned for PULP, this provided an extra
5kW for the Senator, Clubsport, Grange and – in 2001 – the new 5.7 Maloo ute and
Coupe.
For the late 2002 VY series, the HSV LS1 is upgraded to 260kW thanks to a
revision of the extractors, exhaust and ECU tune. The full 260kW output is
enjoyed by all HSV models except for the Grange, which remains at 255kW.
In late 2003 (at the time of the VYII release) the HSV Senator, Grange, GTO,
Clubsport and Maloo received a high-flow cold air intake, a smooth MAF pipe,
sophisticated extractors and exhaust and optimised engine management. Maximum
power is elevated to a substantial 285kW together with 510Nm.
Today, the latest Z series Clubsport, Senator, Grange, Maloo and GTO employs
a 6.0 litre LS2 with a 10.9:1 compression ratio, free-flow exhaust, 90mm
electronic throttle body and PULP-specific PCM tune. Power output is 297kW
together with 530Nm – see GM's LS2 V8 for more details.
Newly introduced models to the HSV line-up are the LS1-powered Coupe 4 and
Avalanche (both AWDs). These vehicles share an identical HSV MAF pipe, stainless
steel extractors and a unique dual exhaust. Peak output is 270kW and 475Nm for
both.
Note that the all-time most powerful LS1 used in the HSV range is the
Callaway C4B engine. The C4B comes with a very low restriction exhaust, CNC
ported heads, revised valves and cam, uprated valve springs and titanium
retainers. A 78mm throttle body, large induction pipe and a MAP-based load
sensing system were also introduced. This engine is fitted to the HSV GTS (sedan
and coupe), SV300 and limited edition Senator 300.
Stay tuned for Part 2 – we’ll look at basic LS1 mods.
Did you enjoy this article?
Please consider supporting AutoSpeed with a small contribution. More Info...
|
More of our most popular articles.
|
|
|
Email a friend
Print article
|