Reply to thread

See what others are reading now! Try Forums > Current Activity

Message: <blockquote data-quote="sakuraguy" data-source="post: 2414243" data-attributes="member: 6441">0–200: 20.3 secondshttp://img64.imageshack.us/img64/4205/vipermi5.jpgIn this awesomely powerful Viper's first run, Millen is instructed by John Hennessey to launch the Viper at 3300 rpm and upshift at 6000 rpm. Millen does this, and at 203 mph in 5th gear, with the thoroughly tweaked 8.5-liter V-10 singing at 6000 rpm well before the mile, he drops it into 6th gear. When Hennessey learns of this later, he tells Steve to keep the car in 5th during the next run and let the engine rev past 6000 for better performance as the car streaks to 200 and on through the mile. Well, an hour or so later, after the Hennessey crew cools the car's intake tract with ice and wet towels and warms the rear tires with electric blankets, that's just what Millen does. Not surprisingly, he posts the best time of the day, a 0–200-mph blast of 20.3 sec., in only 3488 ft. That's 472 ft. less than three quarters of a mile! And with a peak speed of 220.3 mph in the mile, the Viper sets a new R&T record. Steve describes it best: "Holy Hell! This is a wild ride. It just wants to go sideways in every gear. When you're taking off, you've got to be so careful with the throttle. In 2nd, you've still got to be careful. It'll take a bit more throttle in 3rd. When you put it in 4th, you can go flat, but I had it snap loose with wheelspin. It's not until the middle of 4th gear that the Viper is really hooking up, producing lots of horsepower and torque." Power is clearly not the issue with the Hennessey Viper. Grip is. Steve says this makes each run a series of constant minor steering corrections to counter the loss of traction from wheelspin. To that end, Hennessey fits the Venom 1000 with a trick programmable speed-related boost controller that helps ration the power. From launch to 60, there's 8 lb. of boost, which helps the bored and stroked V-10 to produce 800 bhp at the rear wheels. From 60 to 90 mph, boost is raised to 10 lb. for 900 bhp. From 90 to 120 mph, it's 14 lb. for a nice even 1000 bhp. And at 120 plus, 16 lb. of boost endows the big pushrod aluminum powerplant with 1100 bhp, 99 more than the claimed output of the Veyron (although Volkswagen engineers have hinted their official statistics are conservative).The Hennessey's increasing power at speed — and the sheer difficulty of launching a rear-drive car with 800–1100 bhp — is reflected in our test results: From 100 to 200 mph, in that rarefied arena where precious few cars can play, the Viper absolutely devours the competition, taking only 13.0 sec. and 2956 ft. to accomplish this feat. The next closest car, by no means a slouch, is the Bugatti Veyron, which needs 18.0 sec. and 4229 ft. for its blast from 100 to 200. Hennessey, who builds 24 Venom Twin Turbo Vipers for each model year at his Houston shop, says he wants to give his customers 1000 bhp, but feels a need to give it to them progressively. "Most of our clients don't get the full 1000 bhp until about 100 mph," says John. "A little bit of wheelspin is fun; a lot is counterproductive to going fast."</blockquote>