Ford's 2,521cc Duractec five-cylinder petrol engine comes with a single turbocharger that delivers 305hp at 6,500rpm and can rev to a 7,050rpm redline. If the engine's ECU senses no gearchange at the redline, it will automatically reduce revs to 6,500rpm to avoid damage. To achieve its 305hp over the
Focus ST
on which the engine block is based, Ford used a larger turbo, exhaust downpipe, intercooler, stronger forged crank to cope, and lighter pistons with graphite coating for minimal friction.
Engine tweaks over ST were comprehensive
Coupled to an uprated version of the ST's six-speed manual gearbox, which had the same ratios as the ST but stronger bearings, clutch housing and a Quaife helical LSD, the RS was a much more bespoke car. Despite all of the changes, however, the RS has proved to be incredibly reliable for such a powerful hot hatch.
Early cars suffered from a few with exploding plenum chambers due to a backfire, but Ford solved this with a remap of the fuelling. Some tuned cars can still experience this, so a cast aluminium plenum chamber is advised for more heavily modified cars.
At the same time Ford launched the RS500 in 2010, the company also unveiled the Mountune-developed MP350 kit that cost £1,995. Due to demand for the RS500 and limited supply, Ford recognised a desire among standard RS owners for increased performance which the MP350 kit provided it by taking the engine to 350PS with upgrades that consisted of a larger air box, larger diameter exhaust downpipe and higher capacity fuel pump, as well as a reworked ECU.
305hp not enough? Mountune can help
The Mountune kit had the distinct advantage of being factory-approved to retain warranty cover and it comes with its own Association of British Insurers code to make insurance easy and relatively affordable for a modified car. Mountune has since gone on to offer its own MP375 upgrade to take power to 375hp and drop the 0-62mph time to 5.0 seconds. This kit has a three-inch exhaust downpipe, sports catalyst and cat-back exhaust, cast aluminium inlet plenum, recirculating bypass valve and upgraded engine map. However, this kit is not backed by Ford's warranty.
There are other tuning kits out there for the Focus RS Mk2, from the likes of Graham Goode Racing and BBR, that offer improvements in power to 335hp and all the way to 400hp. The Focus's engine seems happy to take such hikes in power, but anything beyond 400hp will require larger fuel injectors to keep the engine reliable.
Service intervals are spread quite far apart for the RS, with an initial 2,500-mile check then leading to the next scheduled service at 25,000 miles. Many owners will prefer to have the car serviced every 12 months rather than wait for the miles to accumulate, so check the car's service record carefully for evidence of a fastidious owner.
Tuned and standard cars will benefit from an engine stabiliser bar, which is £102 from Graham Goode Racing, plus fitting. It eliminates vibration and helps the engine transfer power more smoothly to the wheels. Otherwise, there's very little to worry about under the bonnet of the RS Mk2.
PHer's view:
"If I was to need a rabid getaway car, or need to get 50 miles down a piece of British B-road quickly, I'd take the RS over any car. It's simply more composed and exploitable to drive at nine or 10 tenths. The chassis is brilliantly balanced and it really can be driven incredibly hard without issue."
Mark Harries