*The R56 MINI Cooper S is pretty quick from the factory, its 1.6-liter turbo four is rated at 172 hp and 177 lb-ft of torque, but it feels a little higher than that. We wanted to see what we could wring out with some basic bolt-on performance parts, so we called Alta MINI Performance to improve breathing first, then GIAC to turn up the boost a little.
2007 MINI Cooper S
Transmission: Six-speed manual
Testing octane: 91
Peak wheel-hp: 167 @ 5400 rpm
Peak wheel-torque: 182 lb-ft @ 4300 rpm
Temperature: 64 to 68 degrees F
Test gear: Third
*Notes: As is the case with most factory turbo cars we've tested recently, this one is making substantially more power than its makers claim. During the testing process, O2 sensor data was also logged and we found that the stock car runs extremely lean-not necessarily detrimental, but somewhat surprising. The car was tested with both the sport button active and non-active-no difference was found.
Alta Open-Element Intake
Peak wheel-hp: 172 @ 5600 rpm
Peak wheel torque: 183 lb-ft @ 4350 rpm
Maximum wheel-hp gain: 9 @ 5900 rpm
Maximum wheel-torque gain: 10 lb-ft @ 3200 rpm
*Install process: Removing the stock airbox is straightforward and painless, removing a couple of screws that hold the box in place and then removing the clamps on the stock hoses. The new intake shroud attaches to factory mounting points and includes a new elbow to connect the filter to the MAF and a coupling for the factory intake. Installation time is about a half hour to an hour and requires basic hand tools.
Well-built components made from quality materials A little more intake noise along with a whoosh from the diverter valve could be good (or bad) Makes power across the rev range
We'd like to see the filter shrouded from engine heat and maybe an intake funnel inside the filter to smooth flow before the elbow
*Notes: The intake showed a measurable gain across the entire powerband and definitely improved the sound. The stock airbox is nearly adequate for standard amounts of boost. This is one of those mods that will come into its own when more changes have been made.
Alta Cat Back Exhaust
Peak wheel-hp: 170 @ 5600 rpm
Peak wheel-torque: 187 lb-ft @ 4400 rpm
Maximum wheel-hp gain: 4 @ 4450 rpm
Maximum wheel-torque gain: 5 lb-ft @ 4400 rpm
*Install process: This involves cutting the factory exhaust just behind the second catalytic converter and installing the supplied clamp-on adapter. The center and rear section are held together with high-quality V-band clamps and use the factory hangers. The entire process took less than 45 minutes using a lift and power tools to cut the factory system.
Factory-like build quality and better-than-factory looks Makes a deeper, throatier sound without being much louder than stock-and no drone
The catalytic converters seem to be the real bottleneck, not what's behind We'd recommend installing Alta's downpipe at the same time
*Notes: We're impressed with the quality, sound and ease of install, but to really get the full advantage in terms of power; we recommend buying the full turbo-back exhaust. It lost a couple of hp at peak power, but created a bigger surge in the midrange.
GIAC Software Flash
Peak wheel-hp: 180 @ 5450-6175 rpm
Peak wheel-torque: 202 lb-ft @ 4300 rpm
Maximum wheel-hp gain: 14 @ 4300 rpm
Maximum wheel torque gain: 16 lb-ft @ 4250 rpm
*Install process: Software flash through the OBD-II port.
Huge power and torque; the car will now spin its tires in second gear even with the limited-slip diff Factory smoothness and no dead spots or hesitation
GIAC tells us the turbo can't be used to its full extent because of high intake temperatures
Notes: In the upper rev range, the car is restricted to just over 16 psi because of intake temps. With a larger intercooler, GIAC is convinced more boost is possible, meaning more power.
As with most turbo cars, the software is the first big step. While we saw gains from the intake and exhaust, our testing made us think a front-mount intercooler might be an even better first step. We'd also recommend Alta's full turbo-back exhaust (instead of just the cat-back) to maximize power. All components are nicely engineered and well built. None require a sacrifice in comfort or driveability for the sake of performance.