Making more output from a turbocharged engine has long been the lowest-hanging fruit of the tuning industry, especially when reflashing an ECU with a new map can easily make more power. Sometimes much more power.
That's not the case here. The Ford Focus RS Mountune upgrade, available in Europe, gets only modest stated increases-20 horsepower and 26 lb-ft over the standard RS, a car rarely criticized for being short of firepower-but, crucially, it's sold with Ford's full approval and warranty support.
Mountune has a long history of extracting more power from production cars and working as a specialist race-engine builder, but in recent years it has become Ford of Europe's go-to arm for tuning upgrades. As well as an ECU reflash, the RS375 kit brings high-flow silicone intake tubing, an upgraded recirculation valve, and what's described as a sound suppressor to cut down on noise from the increase in boost. Most important, it also comes with Mountune badges to ruin the day of mere Focus RS drivers.
Any fears that such a modest increase in power and torque won't be detectable are nullified as soon as you start to drive the RS375. These are big horses, the sort that get the Jockey Club ordering blood tests. The Mountune-tweaked car feels instantly keener and brawnier, pretty much across the entire rev range. We suspect the quoted gains are deliberately conservative to help appease Europe's insurance companies.
The most obvious change is the Mountune car's snappier responses on part throttle, with reduced lag and the sense of improved pickup at lower engine speeds. One also feels the midrange punching harder, and there's a marked increase in enthusiasm for exploring the final 1000 rpm of the rev range. The engine sounds stronger, too, with louder induction noises that get very throaty on full acceleration, like Darth Vader making an obscene phone call.
Ford claims the power boost cuts two-tenths of a second from the Euro-spec RS's claimed 4.7-second zero-to-62-mph time (we timed the standard car at 4.6 seconds to 60). We weren't in any position to quantify the improvement, since our test car was riding on winter tires and being driven in the French Alps over roads often covered in ice and snow. But the low-grip surfaces gave the boosted RS a chance to show its enthusiasm for sending output to its clever torque-vectoring rear axle whenever possible. In slippery conditions, this can be felt working almost all the time, trying to keep the car on its intended line or to drift a little bit beyond it, even in the regular Dynamic mode and not the much lauded Drift mode. The sharpened engine responses were also both obvious and beneficial with the small accelerator openings required when driving on snow and ice.
Beyond the engine, the Mountune kit brings no other mechanical changes; the company does sell plenty of other aftermarket upgrades, although without the same level of warranty support. For its part, Ford is confident the standard RS brakes and chassis are more than up to dealing with the boost in output. We also can report that the RS rides noticeably better on winter tires than it does on summer-grade rubber, and the enthusiasm of the front wheels to sniff out and follow interesting bumps and cambers is at least partly muted.
We're sad to say this is another of those European stories that ends up being summarized with three words: not for us. Or, at least, not for now. Ford said it is still debating whether to bring the Mountune kit to other markets, including the United States, but it's currently limited to Europe. In the U.K., it costs Â£900 ($1100 at current exchange rates) before installation at a Ford-approved Mountune dealer. That's a steep price to pay compared to some of the cheaper ECU reflashes, many of which offer higher stated power increases, but the continued protection of the Ford warranty will be reassuring enough to persuade many RS owners to buy the Mountune kit. (U.S. do-it-yourselfers should visit www.mountuneusa.com or the outfit's Carson, California, shop.)
We also presume that the Mountune-tweaked RS won't be where the story ends-certainly not for European RS buyers. Ford made a more powerful RS500 version of the previous Focus RS, and we've already reported that there are plans to do something similar with the current car before it retires. Given that the last RS500 enjoyed an increase of 45 horsepower over the standard car, we can safely predict at least that much for the current RS, leapfrogging the output boost of the Mountune kit. That's the upgrade we really hope Ford brings to the United States.
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