The Dodge Viper special editions continue, and on Thursday a turnkey race car, called the Viper SRT10 ACR-X, broke cover.

It’s not street-legal and is upgraded with a slew of performance modifications aimed at racing enthusiasts. Power grows by 40 hp, to 640 hp, for the 8.4-liter V10. The suspension is tuned for the track, and weight is cut by 160 pounds compared with a standard production Viper.

A Viper ACR-X turned 1:31 laps at Laguna Seca last month, Dodge says. That’s about three seconds faster than the time turned in by a production ACR at the track, which the company says is the record.

The car follows on the heels of the Viper 1:33 and Voodoo editions, the other special versions of the Dodge supercar announced so far. The current generation of the Viper will end production as a 2010 model with a run of 500 copies. The ACR-X will have an MSRP of $110,000, and production is expected to begin in the spring of next year.

The powerful racer will launch this summer as part of a new spec series called the Dodge Viper Cup. It will be sanctioned by the current Viper Racing League, but each car must be an ACR. Two races will be run over five weekends, starting July 9-11, 2010, at Virginia International Raceway. The series wraps Oct. 22-24 at Daytona International Speedway.

It is sponsored by Dodge Motorsports and Mopar, with cash prizes of $6,500 and $1,000 in Mopar vouchers for first-place finishes.