The new Ford Focus RS is a hot hatch->ke304 that is sure spawn a wide offering of aftermarket performance offerings ranging from cold air intake systems all the way to more extensive engine and transmission upgrades. Only being around for a short time, model-specific aftermarket performance options are far and few between right now, but Mountune USA has finally released a decent list of upgrades known as Phase 1, which undoubtedly means there will be more to come.

Each piece of the Phase 1 tuning kit can be bought separately. The upgrade list starts out with a Mountune high-flow air filter and high-flow induction hoses that are priced at $59.00 and $69.00, respectively. Next on the list is the ultra-high-performance silicone boost hose kit that retails for $315. More in-depth bolt on parts include a roll restrictor for $159, which is basically a stiffer rear engine mount that cuts back on engine movement during launch, shifting, and heavy acceleration. There is also a quick-shift upgrade which replaces the standard shift arm on the transmission for $199.

There are two other options, which are a little more expensive. First on the list is the OZ Leggera wheels, which as you can see in the attached video, offer just enough clearance for those large RS calipers on the front axle. The wheels are 3.7 pounds lighter than the stock OE wheels, are ET45 offset, and are 19-inchs in size. The wheels are priced at $485, but that doesn’t include tires, which are sure to set you back at least that much, if not more. The big news in the Phase 1 tuning kit is the $1,099 Quaife ATB differential that helps maximize traction, minimize wheel spin and torque steer, and is maintenance free. Mountune USA hasn’t announced an installation kit for the differential, but for the Focus ST, the installation kit runs $124.

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Why it matters

To be honest, I haven’t kept up too much on the aftermarket offerings for the new Focus RS. I assume there are some other aftermarket upgrades out there too, but considering the Focus is so new, I know there isn’t a plethora of options out there quite yet. For the first decent listing of performance upgrades I’ve seen, I would have to say that Mountune USA has done a fairly decent job. The air filter, hoses, engine mount and even the quick shifter are all relatively easy bolt-on upgrades that can be installed on the weekend by your average car guy. I’m not sure how big of a deal the wheels are at this point, but I’ve heard a lot of aftermarket wheels won’t fit the RS because of the brake system, so if aftermarket wheels are still hard to come by, $485 isn’t a bad price for those sporty, 10-spoke, 19-inch rollers.

The biggest news, I think, is the new differential. As I said, I haven’t exactly been looking for Focus RS upgrades, but I haven’t heard of anything else like this for Ford’s newest hatch. According to Mountune, the ATB differential relies on gears instead of clutches, which makes for smoother operation without any harsh locking. Furthermore, the differential automatically biases the torque to the wheel that is spinning less with a “constantly varying degree.” Mountune hasn’t disclosed how much extra power or torque you can get out of all these upgrades. I would assume maybe upward of 10 horses with the high-flow filter and tubing. Shift times will obviously decrease with shorter throws, and the weight reduction from the wheels is better than nothing. For the most part, these upgrades will make the car a little smoother to drive and will provide some small performance gains. But hey, a little gain is better than no gain at all, right?

Ford Focus RS

Read our full review on the Ford Focus RS here.