FG Falcon: Inline Aussie six's final swansong
BY JAMES STANFORD | 17th Feb 2008
A new five-speed automatic replaces the base four-speed automatic, a new six-speed manual has also been introduced and the existing ZF six-speed automatic has been retained.
Both XR models have been given a big boost in power and torque, while the standard inline six-cylinder engine has been further refined and given a mild performance increase.
Ford Australia did not make the same mistake as Holden, which hadn’t calculated its fuel economy by the time the VE Commodore was unveiled, and has put a full set of fuel figures on the table.
They show the FG program delivering fuel economy improvements of between one per cent and 5.3 per cent.
The engine line-up again includes the base 4.0-litre inline six-cylinder, a turbocharged version and the 5.4-litre quad-cam Boss V8.
Ford Australia dropped the three-valve per cylinder 5.4-litre V8 from the Falcon range last year and it is also missing from the FG line-up.
The E-Gas LPG 4.0-litre six soldiers on using its existing gas injection system, with Ford baulking at upgrading the economical powerplant to a more expensive sequential vapour gas injection dual-fuel system that is available for the VE Commodore.
The E-Gas unit is the only engine that will continue to use the old four-speed automatic transmission produced by Drivetrain Systems International in Albury.
Performance increases are most evident with the XR models.
The XR8 now runs what is essentially the BF GT engine and pumps out 290kW and 520Nm of torque, making it a performance bargain.
Ford saved the biggest changes for its boosted I6 engine that powers the XR6 Turbo.
Its power out jumps 25kW to 270kW and torque rises by a hefty 53Nm to 533Nm.
The standard I6 engine’s output increases by 5kW to 195kW, while torque inches up 8Nm to 391Nm using regular 91 RON fuel. Spend a bit extra for 95 RON premium fuel and the output climbs to 198kW and 409Nm.
The changes made to the I6 are greater than the numbers suggest and the FG work is expected to be the last major update before the engine is replaced by a Ford US-built V6 in 2010 after 50 years of service.
Fuel economy was a major target for engineers, who also worked on improving driveability.
The base engine, now paired with a five-speed automatic instead of a four, uses 10.5L/100km, a 1.9 per cent improvement.
Premium FG Falcons fitted with the ZF six-speed automatic now use 10.1L/100km, which is down by 1 per cent.
The fuel economy story gets better when it comes to the performance Turbo six and the Boss V8.
Changes have seen the more potent Turbo cut its fuel use by 4.9 per cent to a respectable 11.7L/100km.
The 5.4-litre Boss is still a thirsty beast, using 14.2L/100km, but that is a big improvement over the engine in BF form that used 15.0L/100km.
The I6 4.0-litre base engine carries on with the dual overhead cams (which are independently variable) and four valves per cylinder, but has a new cylinder-head, new intake manifold and revised calibration.
A new composite (plastic with 30 per cent grade glass-filled nylon) dual-mode split plenum intake manifold that includes an electronic throttle body and fuel rail assembly, replacing the old aluminium casting and saving 4kg.
Ford says it also increases the power of the engine, improves power delivery and responsiveness, as well as improving fuel economy and sound quality.
“This dual mode, equal runner length, system geometry has been tuned to achieve good low-end torque and peak power characteristics, with smooth transitions at the valve switch points to a achieve a high level of performance feel,” said Ford Australia powertrain engineering manager, Lee Kernich.
Both the naturally-aspirated and turbocharged FG six-cylinder engines feature a ‘fast burn’ cylinder-head for improved fuel economy.
The new head has a revised intake port profile and combustion chamber geometry to create additional ‘swirl’ in the combustion chamber for a faster burn rate.
As a result, pumping losses are reduced and fuel economy is improved.
The turbo also features a range of other hardware and calibration upgrades including a new Garrett turbo that responds 30 per cent faster.
“It has been optimised to operate in a higher efficiency range, which allows boost to come on quicker and therefore minimizes turbo lag even further,” Mr Kernich said.
Maximum turbo boost pressure has increased from 6psi and 10psi (0.4 bar to 0.7 bar).
A new intercooler features a 50 per cent larger core volume, 40 per cent improved heat rejection and a 34 per cent reduction in flow reduction.
The complete air induction system has been redesigned to reduce flow restrictions and volume and there is also a new single-runner intake manifold.
Ford has increased the compression ratio from 8.7:1 to 8.8:1, while a new exhaust manifold frees up exhaust gas flow into the turbocharger.
The I6 Turbo’s maximum power of 270kW is delivered at 5250rpm, while the torque output of 533Nm is available all the way from 2000rpm to 4750rpm.
Ford Australia has also included a transient overboost feature that allows the engine to overboost by up to 10 per cent for several seconds, which the company says will help for situations like overtaking.
There is also an anti-lag launch feature for manual models.
When the vehicle is stationary, with clutch fully engaged and enough throttle applied, the engine revs are limited 3500rpm.
After two to three seconds, the turbo spools up with 80 per cent fresh air that is pumped into the deactivated cylinders. All cylinders are reactivated when the clutch is released.
The idea is to both cut turbo lag and also protect the drivetrain as drivers don’t need to slip the clutch (and risk burning it out) to get off the line briskly.
Turbo engines linked to automatic transmissions feature a cylinder cut-out, which lasts for 0.25 seconds, for shorter and sharper gearshifts.
The Boss V8 engine featured in the BF-model FPV GT. It is hand-built from imported blocks and heads, including a range of FPV components.
It delivers its 290kW at 5750rpm and its 520Nm at 4750rpm.
The Boss V8 has not been changed significantly, but does feature a new oil pan and new exhaust manifolds to suit the new body structure and the engine cut-out feature for quicker gear-changing with automatic models.
Ford has also fitted the XR8 engine with a new Semi Active Muffler which it borrowed from Aston Martin and Jaguar.
This system comprises of a spring-loaded valve in the muffler which opens and closes depending on exhaust pressure.
When it is closed, the exhaust gas has to pass through a series of baffles in the intermediate muffler.
At engine speeds higher than 2800rpm, there is enough pressure to open the valve and have the exhaust gas bypass the other baffles.
The idea is to maintain a quiet interior at low speeds and deliver a loud V8 note at higher speeds.
The SAM muffler also enables to the XR8 models to pass the Australian Design Rule drive-by road tests and still deliver a sporty exhaust note.
Replacing the four-speed automatic transmission on all models except for the E-Gas and continuing BF wagon is a five-speed automatic that is produced in Bordeaux, France.
It is an internally-sourced Ford Motor Company transmission and features a manual-shift mode.
The new gearbox features a wider ratio spread and a first gear that is lower than the old four-speed's, which should deliver a better launch feel.
It features a torque convertor lock-up that can be engaged in all gears when high load conditions or steep grades are detected.
The new six-speed manual is a Tremec TR6060, replaces the T56 six-speed manual and the T5 five-speed manual used for the base Utes.
There are three variants of the gearbox, with different ratios tuned for the different applications.
A new synchroniser package features triple synchromesh on first and second gears and double synchros on all other gears, including reverse.
XR6 Turbo and XR8 manuals now feature a 290mm diameter self-adjusting clutch, replacing a smaller conventional clutch.
A revised cruise control system now moves up and down in increments of 1km/h instead of 2km/h, a move made to combat increasingly strict speed monitoring on Australian roads.
It can also move by up to 10km/h if the button is depressed for long enough.
FG Falcon fuel tanks have been redesigned and now feature a new fuel sender that Ford Australia said was more resistant to sulphur-rich Australian fuel.
The company said the new fuel sender signals are more consistent, especially over time, and allow for more accurate fuel consumption and distance-to-empty readings.
Read more:
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FG Falcon: Ford goes to finishing school
FG Falcon: Engineered to lead