The calculations made by the team suggested that at least 800 hp would be required to overcome the profile drag of the Turbo-width body, and the downforce created by the new front and rear spoilers required to keep the car stable at a V-max beyond 200 mph.
The faster you go, the greater the downforce, and these loadings have to be taken into account when the spring and damper setup is being developed. That in itself is an issue because you want the suspension to be supple at low speeds around town, yet have cast-iron control over body movement at high speeds.
Apart from saving weight and gaining a huge amount of horsepower, every effort was made to save power. To this end, an electric power steering system was used to reduce drag on the engine.
The idea of braking from 240 mph is frightening if you're trying to avoid a obstacles on the autobahn, but in high-speed testing at Nardo or Papenburg, it isn't really an issue as there are no other cars to hit. You go around and around the track and have literally kilometers to stop. Nonetheless, to make sure the car will stop quickly on the road, it comes with the best brakes that will fit behind the Sportec alloy wheels. These include massive 380x34mm ceramic rotors clamped by six-pot calipers in front, and 350x28mm rotors with four-pot calipers at the rear. The factory Porsche PSM system is still there and plumbed in, but Sportec has arranged things in such a way that it can be totally disabled. Then Sportec's own Swiss-made traction control system, adjustable from two to 30 percent, takes over.
Despite the extra power, Sportec is not claiming better acceleration numbers for the M version than the SPR1. Even so, like the top-speed figure accredited by the Nardo officials, the recorded numbers of zero-to-100 km/h in 3.0 seconds, zero-to-200 km/h in 8.6 seconds, and zero-to-300 km/h in 18.9 seconds make this one seriously quick car. But driving the SPR1 around the countryside near the town of Bulach, near Zurich, where Sportec is based, proved that the car is tractable enough to use as a daily driver. The improvement in low-end response over the SPR1 is quite pronounced, and makes the M version a lot easier to drive at low speeds.
Upshifting at 3000 rpm, you'll find its manners now little different from a stock Turbo. Its finely balanced hand-built turbos prove the point that if you build them properly, you don't need VTG turbos for good down-low response. The only proviso in the car's potential as a daily driver is that the race-grade clutch is heavier to use than stock, although this is not really an issue unless you're stuck in a traffic jam.
While it may exhibit civilized manners in normal driving, once you prod this beast, you know you have released a wild animal whose pace is ably assisted by brute force and a following wind.
In full cry, the push in the back is fierce and unrelenting, and although the traction of any 911 is helped by the weight of the engine over the rear wheels, you feel that the AWD system is really earning its keep as the SPR1M slingshots down the road.
On the straight bits between the bends, the car's ability to compress distance is simply awesome, as is the eyeball-popping retardation offered by the brakes.
The suspension is firm, but its secondary ride has a welcome suppleness that keeps things civilized, so you don't end the drive feeling you've gone 10 rounds with Mike Tyson. With so many horses to unleash, this suppleness is absolutely necessary for getting the power to the ground, especially in bumpy corners.
Although the SPR1M does not rev as high as its predecessor, it still takes some mental adjustment to push a 997 Turbo engine past 7500 rpm. But once you've tried it and realize that the revs are still building at 8000 rpm, you just can't get enough of the sound and feel of the flat-six screaming to 8400-rpm redline. The feeling of being warped into another dimension of Porsche driving never before encountered is quite addictive.