Hennessey's Vipers are fast, but lawsuits say he serves them up too slowly.

Ninety-eight percent of his customers love him, John Hennessey says. But a few hate him and some have sued. Hennessey Motorsports in Houston specializes in tuning Vipers, adding more power to what is already one of the most powerful cars in the world. Hennessey’s Vipers have been featured in this and many other magazines and the cars he has sent to us and to other media were impressive performers. Hennessey presents himself well, projecting an image of the consummate Texas good ol’ boy whose reassuring conversational style and howyewdoin’ demeanor put customers at ease. People believe they will get what he says he’ll give them. But not all people do.

According to a lawsuit filed in Salt Lake City, Utah resident Taig Stewart sent his Viper GTS to Hennessey last May for an engine upgrade to 1100 hp along with several other modifications. For that he wire-transferred $142,500 to Hennessey. The lawsuit states the parties agreed the car would be done by mid-July 2001. As of press time the car was still sitting under a tarp in Hennessey’s shop in Houston. Or most of the car, anyway. Stewart’s suit claims Hennessey sold the car’s engine, transmission, wheels, tires and hood. The suit seeks return of the money, the Viper and “no less than $1 million” in punitive damages.

Hennessey claims he’s just slow in getting the work done.

“My side of the story is we’re planning on finishing his car and planning on giving him everything that he paid for,” said Hennessey. As for the parts being sold, “That’s totally false. We’ve got all his parts in the shop except the hood and he wanted to do a lightweight hood.”

Stewart is not the first unsatisfied customer. The longer we dug the more dissatisfaction we found. Here’s a sampling:

On Nov. 14 a New Jersey court entered a final judgement of $133,674 against Hennessey on behalf of Viper owner Gary Dan for a botched conversion.

William Walters said he is out over $22,000 after shipping his Corvette to Hennessey for a head and cam package that was never done; he did have five rods bent and a head gasket damaged on the dyno in Hennessey’s shop during an experiment Hennessey tried with nitrous oxide.

Jerry Johnson said he had to file suit in Placer County Court in California to straighten out registration and engine computer problems on a Viper he bought from Hennessey. n Jon Belinkie said he loves the changes made to his Viper but had to sue in his home state of Maryland, then register the judgement in Texas, to recover overcharges Hennessey made on his American Express card.

Rick Ryan said he had to hound Hennessey for eight months by long distance from Marietta, Georgia, to put the proper wing and stripes on his Viper.

Mark Lublin said he sent his Viper cylinder heads to Hennessey for new valves but when the heads came back he found the “new” valves were actually used; a cam that was delivered to Lublin in a Hennessey box turned out to be a stock Chrysler cam. Lublin was finally refunded $5,715 from American Express but only after nine months of disputing the charge; and he got no money from Hennessey.

Bruce Iannatuono said he ordered $8,500 worth of Hennessey parts for his mechanic in Baltimore to install but was only able to use two-thirds of what was shipped, and then only after haranguing Hennessey for six months on an order that was originally promised in five weeks.

Most of the complaints come from outside Texas. Hennessey, some said, tends to take better care of local customers.

“If you were out of state, man you were fair game,” said Kyle Kent, a former employee at Hennessey Motorsports. When an out-of-state car came in it was sometimes parted out, with the wheels, tires and whatever else looked good going to other cars waiting to be finished or sold outright, according to Kent and others inside Hennessey Motorsports. Then Hennessey would call the car’s owner and try to sell him an upgraded kit. If the customer balked, Hennessey would take parts from other cars in the shop, or just let the job sit.

Kent described one typical disassembly on an out-of-state Viper. “The motor and transmission went into a Durango John was putting together, the brakes went to someone else, the hood went to a guy in Ohio, the rear bumper to South Carolina, man you name it. We had multiple cars like that.”

Another common practice was putting stock parts on what was supposed to be an upgraded car.

“One customer spent $130,000 to $140,000 and that guy thought he had purchased a Venom 650R package which he thought came with the stroker motor,” Kent said. “John told him he was getting a stroker. He was just getting heads and cams.”

Hennessey denies any wrongdoing.

“I’ve got probably 3000 customers,” he said. “I’ve built over 300 cars and out of that I’ve had a handful of people that I’ve had some sort of a delivery problem with and I’ve had some of them who have sued me. So is that some sort of a trend or is that par for the course?”