We are back! The Real Madness starts now!! www.highthrottle.com will be launching very soon. The Chase Begins Again... High Throttle: Ford Focus RS


Friday, March 20, 2009

Ford Focus RS

The Ford Focus RS engine shares its fundamental structure with that of Focus ST, but there the similarities end. Powertrain manager Len Urwin knew from the beginning that simply adjusting the engine management system for more power would be insufficient for a true RS. 

He explains: "There was never an intention to try to 'chip' the ST engine. We evaluated several approaches using the ST engine and none gave us the combination of power delivery, character and durability that we wanted, so we opted to create an RS Duratec, using the ST unit as our base." 

The objective was increasing power and torque without affecting durability. To meet that, multiple detail changes were made to the powertrain including a revised cylinder head gasket, ultra-durable metal sprayed cylinder bores, revised pistons and a bespoke camshaft profile and connecting rods, allowing bigger small end bearings. 

However, the most obvious changes are the new intake system, exhaust manifold and turbocharger. The larger Borg Warner K16 turbo fitted to Ford Focus RS offers a maximum steady state boost pressure of 1.4 bar - double that of Focus ST's 0.7 bar - to generate the car's 35 per cent power increase. 

Committed to maintaining responsiveness of the engine, Urwin's team focused on three areas: 

Integrating the turbo with the exhaust manifold, to allow subtle manifold tuning and strategically locating the turbo in the engine bay, to optimise crash performance and minimise revision to the exhaust system and associated oil and water pipes; 
Carefully sizing the required larger turbo, to closely match the 'bottom end' engine responsiveness of Focus ST; 
Reducing the induction system and exhaust losses. 
Ford Focus RS needed its own, more aggressive performance character so engineers also modified the torque 'ramp-up', to enhance performance feel when on boost. 

"While we wanted to be equal on low-end responsiveness and minimise the common off-boost inertia of larger turbos, we didn't want RS to have the same character as ST," explains Urwin. "We wanted a stronger feel of increasing boost; we wanted you to really feel the surge of the turbo." 

With the turbo spinning, power arrives quickly. The 305PS peak is reached at 6,500 rpm and holds until the 7,050 rpm redline, to allow full use of the top of the power band. After three seconds at this redline, the engine management system recognises no gear shift and then limits revs to the car's maximum continuous running rpm of 6,500. 

"Turbo engines with flat torque curves can often feel like they run out of steam at the top-end, but we wanted to reward drivers who took Ford Focus RS to the red line," states Urwin. "We're really proud of the result - strong mid-range transient response and a free revving top-end." 

Straight Torque 

However, Urwin believes that the power is unlikely to be the first thing drivers will notice, as to get to that redline they will have travelled along Ford Focus RS' 440Nm torque curve. 

Offering more torque than any Ford RS production car before it, Focus RS' torque curve has a steady state peak beginning at 2,300 rpm and running to 4,500 rpm, meaning torque can be appreciated in any gear and at most road speeds. The 440Nm peak torque is a 38 per cent increase over Focus ST. 

Says Urwin: "Matching low-end responsiveness with a larger turbo and a peak of 440Nm is a real achievement. That's a figure you would only have seen in so-called 'supercars' just a few years ago. It gives Ford Focus RS a gutsy, strong pull at the lower end of the rev range - great for those wanting a powerful performance feel but also great for more relaxed everyday driving." 

Creating the power of a true Ford RS is one thing; managing that power into accessible yet exhilarating performance and assured traction is another. This challenge was met by Ford's renowned vehicle dynamics experts. 

Under the guidance of Chief Programme Engineer, John Wheeler, the Dynamics team was led by Chief Engineer, Dirk Densing, whose relaxed demeanour belies his passion and pedigree in performance cars and motorsport. 

This team has achieved a car capable of 0-100km/h (0-62 mph) in 5.9 seconds and a top speed of 263 km/h (163 mph). 

Wheeler and Densing were determined to create a dynamic mechanical set-up that would provide a pure driving experience, rather than manage power with constant electronic interference or truncation systems. 

The most obvious change is the car's wider track, but the team completed their solution with a suspension technology that was under development at Ford's Research & Advanced Engineering centre (R&AE) in Aachen, Germany. Called 'RevoKnuckle', this innovation was identified early on as offering significant benefit to a new front-wheel-drive RS. 

The combination of wider track and RevoKnuckle front suspension is the reason Ford has been able to do what was thought impossible previously: develop a 305PS (300 bhp), front-wheel-drive car that is not only driveable every day, but faster in many situations than all-wheel-drive performance cars. 

Exhaustive testing and refining in the hands of Team RS' dedicated vehicle dynamics expert, David Put, has also created a set-up for Ford Focus RS that forgives the bumps of every day roads, yet rewards on-track commitment. 

"It sounds simple, but is a genuine challenge: make a potent performance machine as accessible and useable as any other Focus; able to transform instantly from everyday transport to track-day 'supercar'," explains Wheeler. "It's a combination of innovative technology and class-leading dynamics, finely honed through David's expertise and commitment that made this possible." 

source : Ford Press