The current king of the hot hatch scene (at least in performance terms) is the Ford Focus RS500, the 345bhp limited edition of Ford’s hot hatch that sold out before it even went on sale. That looks set to change because when the Subaru Impreza STI CS400 hits the streets it will be even more powerful and offer significantly more performance.
Before we talk performance stats it’s worth pointing out that this is no ordinary Subaru. Behind that familiar badge is a name that has set pulses racing amongst hot hatch fans for many years now – Cosworth. The people responsible for many fast Fords over the years are now helping to make the ultimate Impreza. So, forget that clunky name – this is none other than the Impreza Cosworth.
For years there have been rumours of a four-wheel drive Focus RS Cosworth, so it’s ironic to see Cosworth toppling the Focus RS from the top of the tree with a tuned Impreza. But while Ford dithered and never committed to the project, Subaru started talking to Cosworth and the CS400 was born.
Cosworth have been hard at work on the Impreza STi and have altered a lot of the components on the standard car. For a start the 2.5-litre turbocharged engine now is now tuned to 395bhp, an increase of 99bhp. The extra power drops the 0-62mph time down by 1.5 seconds to an incredible 3.7 seconds. That’s a surprisingly quick time, but unlike the Focus RS the Impreza uses four-wheel drive with variable torque-shift, making it much easier to deploy all 395bhp.
The engine work has been substantial and a host of new parts have been fitted, including the turbo, exhaust system, pistons, head gasket and oil filter. One of the most important factors that Cosworth have considered is durability, so you can rest assured that the engine won’t explode the minute the warranty expires.
Another vital ingredient of the Impreza Cosworth is that the car feels like a proper Subaru, that it is a fast road car rather than a track day special. This led Cosworth to tune more than the engine, they’ve also turned their attention to the suspension and brakes. In order to cope with Britain’s crumbling roads Cosworth have fitted new Eibach springs with Bilstein dampers, dropped the front ride height by10mm and increased the rear track by 10mm. There are also new front brakes, AP Racing units with six-piston callipers and 355mm grooved discs.
Inside Cosworth have re-trimmed the front seats and added thicker bolstering to ensure you’re held securely as you tear around the B-roads of Britain, but other than some additional gloss black trim on the dash the interior remains standard.
Externally the changes are subtle. There are Cosworth badges front and rear, but other than a restyled front bumper there’s very little to distinguish the fastest of the Impreza range. Even the dark grey alloys are relatively understated as Cosworth have stuck to the same 18-inch diameter as the original items.
So what’s the price for all of this? Well, the Impreza Cosworth is going to set you back an eye-watering £49,995. That’s a huge price, especially when you consider the standard STi retails for under £28k, but you are getting a well-developed package – don’t forget that this is much more than a simple ECU remap. There’s also the benefit of exclusivity as Cosworth will only build 75 examples of the CS400, so you can expect residual values to be strong too.
Is that it then? Is that all we’re going to see from this partnership? Probably not, as even though there are no official plans yet there is room in the range for a less powerful (and cheaper) model to sit between the standard STi and the CS400. Perhaps a CS350?