Holden V6 hope

GM HOLDEN could soon become central to a General Motors plan to apply twin-turbo technology to its global V6, details of which have surfaced in the US this week.

Speculation is increasing that GM will soon reveal a twin-turbo version of the new 3.0-litre direct-injection ‘SIDI’ V6 that powers the MY10 Commodore as a direct rival for Ford’s formidable 3.5-litre twin-turbo ‘EcoBoost’ V6.

While the 3.0 TT V6 would follow the global trend towards downsized forced-induction engines and would give Holden a direct competitor for Ford Australia’s XR6 Turbo, it could lead to a twin-turbo version of the Commodore’s 3.6-litre SIDI V6, which may eventually replace the 6.0 and 6.2-litre Chevrolet V8 as Holden’s – and even HSV’s – flagship performance engine.

Given Holden’s Port Melbourne engine plant in Victoria and GM’s St Catherines facility in Canada are the only GM factories that produce the ‘High Feature’ V6 globally, any new derivative of the HFV6 could also lead to a substantial boost to Holden’s recovering engine export business.

Holden revealed a 280kW/480Nm twin-turbo version of 3.6-litre Commodore V6 – then known as the ‘Alloytec 190’ – six years ago in its headline-grabbing ‘Torana TT36’ concept at the 2004 Sydney motor show.

Fitted with twin KO4 Warner turbochargers and an air-to-air intercooler, it was described as a hand-built experimental engine, but a number of other 3.6-litre twin-turbo V6-powered GM concepts have emerged since then.



From top: Jay Leno's one-off twin-turbo Chevrolet Camaro, the 2004 Torana TT36 concept and Holden's 3.0 V6 SIDI engine in production.

The most recent was Chevrolet’s one-off version of the Commodore-based Camaro coupe built for US talk show host Jay Leno at the Specialty Equipment Market Association (SEMA) aftermarket exhibition in Las Vegas last November, which delivered the same 317kW peak power output as HSV’s Corvette-sourced 6.2-litre V8.

The 317kW V6 in the ‘Camaro Jay Leno’ featured two Turbonetics T-3 turbochargers, an air-to-air intercooler, bigger radiator, custom exhaust system and stronger clutch, increasing power by a claimed 40 per cent with “virtually no penalty” in fuel economy over a non-turbocharged 3.6-litre engine.

Now, however, after increasing rumours of a twin-turbo GM V6 in recent years, GM Inside News says it has uncovered GM’s first high-tech V6 turbo engine.

GMIN says GM engineering sources have confirmed that a twin-turbo ‘LF3’-codenamed version of its naturally aspirated LF1 3.0-litre SIDI V6 is in development.

Apart from powering the MY10 Commodore, the latter has also appeared in a number of 2010 GM models, but GMIN says the twin-turbo LF3 will debut in the US in late 2011 or 2012 in the Cadillac XTS, which GM showed as a concept at the Detroit show this year.

The XTS should replace the aged DTS and STS models as Cadillac’s flagship sedan and is likely to also become available with a 3.6-litre plug-in hybrid drivetrain, which appeared in the XTS Platinum Concept and was originally designed for the ill-fated Saturn Vue – and could eventually also power Australia’s Commodore.

Cadillac has a history of debuting new versions of the HFV6 and US reports say that while the 3.0 TT V6 will also power the GM premium brand’s forthcoming ATX compact sedan and even the next-generation Camaro, the XTS will also come with a twin-turbo 3.6-litre SID V6.

No twin-turbo V6 is currently produced by GM, and the only direct-injection engines made at Port Melbourne are destined for the Commodore, while St Catherines’ 3.6 SIDI V6 debuted in Cadillac’s 2007 CTS sedan and also powers the STS and Camaro.

Holden’s 3.0 SIDI V6 delivers 190kW/290Nm, while the 3.6 SIDI V6 offers 210kW/350Nm. Its 3.0 (but not 3.6) SIDI V6 will become E85 ethanol-compatible when Holden releases the first ‘Flex-Fuel’ Commodore late this year, and a dedicated LPG version of the global V6 is also in the works.

Holden also produces a 2.8-litre twin-scroll turbo version of its V6 for Saab, Opel’s Insignia and the Mexico-built Cadillac SRX, which will also offer the LF1 3.0 DISI V6 this year.

Saab’s 2.8T engine produces 206kW/370Nm in the 9-3 Aero, but this engine could eventually be replaced by the LF3 3.0 TT SIDI V6, which is said to offer the performance to match Ford’s 3.5 EcoBoost V6, making it and – potentially – its larger 3.6-litre sibling shoe-ins for Holden’s own Commodore.

The recommencement of Saab production this week, including the fitment of the 2.8T in the (new) 9-5 for the first time, marks a small but significant boost to Holden’s sagging export program.

However, this is likely to be offset by the imminent demise of exports to Italy, where Alfa Romeo fits a Holden-based 3.2-litre V6 in its 159 sedan/wagon, Brera and Spyder.

A new E85-compatible 3.6-litre Pentastar petrol V6 – which will gain direct-injection, turbocharging and MultiAir technologies – from new Fiat subsidiary Chrysler is expected to replace the Holden-made 3.2 V6.

Nevertheless, Holden’s vital engine export program – which no longer includes the archaic Family I petrol four that is still built in Mexico, Hungary, Brazil, China, Argentina and Korea – was has received a significant boost from increasing global demand for the HFV6.

Holden will increase its engine production by 6500 units this year to meet increased global demand, primarily from China for the 3.0 SIDI V6 that powers Buick’s LaCrosse, South Korea for the 3.2 V6 that powers Daewoo’s Captiva and Mexico for the 2.8T.

It says the output of its $400 million Port Melbourne engine plant – which opened in 2003, increasing capacity to 240,000 engines a year – will rise to about 460-480 units a day, to a 2010 forecast of 105,000 V6s.

To meet the demand, Holden has redeployed four engineering staff from its Adelaide assembly operations, and is seeking a further 10 staff for six-month contract positions at its Melbourne engine shop.

The move follows an increase in production at the V6 plant from 240-320 to 440 units a day in November last year, when a second shift was reinstated at Port Melbourne following increased global demand.

While Holden says the additional Port Melbourne engine plant jobs will be reviewed after four months depending on demand, its South Australian vehicle plant at Elizabeth continues to operate on a one-shift/two-crew basis after increasing from about 310 to 340 cars a day from late last year.

At a time when the futures of Toyota and Ford’s Victorian engine plants look more uncertain than ever, E85 and twin-turbo versions of Holden’s staple V6 are sure to help grow more demand for one of Australia’s biggest-volume engine plants.