Ford Fiesta, Focus and Powershift DCT
With the U.S. launch of the Fiesta in summer 2010, Ford has clarified some aspects of its position on the different derivatives of its dual clutch Powershift transmission to be used in the North American and European versions of the model.
While it has been expected for some time that most European Fiestas will employ wet clutch versions of the six-speed Getrag-Ford transmission, gasoline-engine Fiestas sold in the U.S. will use a closely related transmission configured to operate with twin LuK dry clutches. This is already in production at Getrag-America’s plant in Irapauto, Mexico. “We believe this new automatic transmission for the Fiesta will be the most advanced in the segment, offering far better performance than our competitors,” said Piero Aversa, team leader for Powershift development in the U.S.
The expected choice of the wet clutch DCT for the European Fiesta reflects the popularity of high-torque diesel versions in that market. Now, however, some suggestions from Ford insiders that the more efficient dry clutch system could, after all, be used in Europe, too. Last month we reported on the new Ecoboost engine and Powershift DCT transmission in the medium-large S-Max minivan. This two-liter gasoline engine is the first of three different families of Ford’s new-generation technology featuring direct injection, turbocharging and variable valve timing.
The second Ecoboost family is again four cylinder, but this time of around 1.6 liters. It will power top-end versions of the C-segment Focus and the related C-Max medium minivan in Europe, but details will not be revealed until the models launch in the fourth quarter of this year. Ford is unwilling to give specification details or state what type of automatic transmission will be employed – though, again, a wet clutch system looks likeliest for the diesel models, at least.
Where the dry clutch transmission is likely to come in is on future versions of the Fiesta powered by the third engine in the Ecoboost family – a three-cylinder, one liter unit to be built in Cologne and at Ford’s new plant in Romania.
This compact engine could be more powerful than many expect, said the Ford insider, pointing out that in the latest facelifted Ford Mondeo the two-liter Ecoboost now gives 240 hp.
The design of the dry clutch Powershift is unusual in that the transmission needs no oil pump, oil cooler or hydraulics. Instead, the gearshifts are electromechanically actuated. Despite the sensitivity of dry clutch transmissions to overheating, no form of clutch or fluid temperature sensor is included, either. Automotive Engineering International reports that Ford has, instead, chosen a system of virtual temperature sensing using control algorithms that monitor transmission use patterns to predict operating temperatures and trigger the appropriate warnings and interventions. The system will, for instance, detect if the driver is trying to hold the car on a steep upgrade using the gas pedal and creep mode. The driver is alerted to this risky condition when the vehicle does a very short, controlled roll-back to encourage him or her to apply the brake, reports AEI.
Ford has not stated whether the U.S.-specification Powershift will incorporate the enhanced freewheeling function mentioned when the dry clutch transmission was first previewed on the Lincoln C concept car exhibited at the 2009 Detroit auto show.
Story Filed: 10/02/2010
By Tony Lewin, managing editor DCTfacts.com