Hennessey working on 705hp ‘Z700’ Corvette ZR1 for 2010

The world's fastest and most powerful production Corvette, the 638hp (476kW) ZR1 has become the pinnacle of American sports cars. After all, for most ZR1 owners, having a car capable of Nurburgring times of 7m 26s is more than enough to satisfy performance to satisfy their need for speed. However, for the select few who subscribe to the mantra of "too much horsepower is never enough", Hennessey Performance Engineering has something special in store for them next year.

Building upon the already launched ZR700 package, Hennessey is currently working on a new 705hp (526kW) upgrade for the Corvette ZR1 designed for track day enthusiasts as well as professional race drivers. Porsche fans wanting a ready-to-race 911 can order the GT3 RS. Dodge Viper enthusiasts wanting the ultimate road race Viper have the ACR. Now ZR1 owners can opt for the Hennessey Z700 upgrade for their Corvettes.

Hennessey's Z700 performance package starts by upgrading the engine supercharger, exhaust and air induction systems and is dyno tuned to 705hp (526kW) at 6,400rpm and 717lb-ft (970Nm) of torque at 3,200rpm. But this is just the beginning. Additional upgrades include lightweight carbon-fiber wheels with Michelin Pilot Sport Cup tires, which reduce rotating weight by nearly 60lbs.

Hennessey's Z-Aero carbon-fiber front splitter, canards and rear spoiler also add over 300lbs of down force helping to put the added power to the road and track. Rounding out the Z700 upgrade package is a revised interior with lightweight carbon-fiber seats, Alcantara steering wheel and shift knob.

Only 24 examples will be produced, and customers who order a Z700 also get a one-day performance driving instruction course at Hennessey's Lonestar Motorsports Park. Total cost for a base Z700 will start at $207,150, which includes the cost of a donor ZR1 but is essentially double the price.

Later this year Hennessey engineers plan to take the car to the Nurburgring to come back with some performance numbers – and possibly some new records. Some of the claims include a 0-60mph time of 2.9 seconds, 0-100mph in 6.4 seconds, a quarter mile ET of 10.6 seconds at 134mph, and finally a top speed in excess of 212mph.