Oct. 8 (Bloomberg) -- Exposed, exhilarated and vaguely terrified. That’s the best way to describe the cocktail of emotions as I roll onto the Lightning racetrack at New Jersey Motorsports Park in a stupidly fast car that has no roof, doors or windshield.

The Ariel Atom accelerates faster than a Ferrari, yet my upper half is sticking out above the hood. Talk about letting it all hang out.

The Atom is a U.K.-designed racer now also produced in small numbers in Virginia. Costing $65,000 and up, it is meant for amateur motoring on the racetrack.

Racetrack culture used to have two very separate camps: Professional teams running million-dollar cars and blue-collar guys who wrenched in their garages and banged bumpers on weekends.

In recent years the allure has expanded to urban professionals who’d prefer to spend Saturday on the track rather than the golf course, testing the limit of their personal sports cars. Few actually race one another. Car clubs and private- membership racetracks have opened around the country.

In the Northeast, New Jersey Motorsports and Monticello Motor Club have opened in the past two years; Lime Rock Park has also begun a membership program. Lifetime memberships, not including dues, run from $15,000 in New Jersey to $50,000 for a limited membership at Monticello.

Of course, you’ll also need a car and maintaining a track vehicle can be as pricy as the fees.

Weekend Warrior

Take the Atom. This is a weekend warrior with an emphasis on warrior -- we’re talking 0 to 60 mph in under three seconds. Its 1,400 pounds are as light as a whisper, and the four- cylinder engine sits in the rear like a Porsche 911. The chassis and body are composed of a steel-tubing exoskeleton, partly covered by lightweight body panels. It has two seats with racing harnesses.

What you won’t find: Windshield wipers (no windshield), door handles (no door), roof. Nor should you expect power steering, ABS brakes, or electronic stability and traction controls. This is blinding speed at its most elemental -- an ultra-light rocket.

The design is from U.K.-based Ariel Motor Co., which previously licensed the Atom to another U.S. company. Now the license has gone to TMI AutoTech Inc., which is producing an updated version called the Atom 3. The Atoms are made-to-order, and most run to around $80,000.

Honda Power

The new version uses a Honda powertrain. Buyers can choose from a 2.0-liter naturally aspirated engine with 245 horsepower or a supercharged version with 300 hp. This is a big upside, as it’s an extremely reliable setup that can be serviced by any Honda-qualified mechanic. It even takes regular gas -- all of which saves bucks.

“I used to run a Viper and a BMW M5,” said Mark Simons, who owns a Virginia IT consulting firm. “On those cars brake pads and tires would last only a single weekend.” Now he owns an Atom 3, which he has brought to the New Jersey track today. “The Atom’s brakes and tires last an entire racing season -- it’s bulletproof.”

The Atom isn’t technically street legal, though some owners have registered them as kit cars. (It depends on the state and one’s own craftiness.) Simons has brought his in on a trailer.

I’m testing an $80,000 Atom 3 with bright yellow body panels. I put on my full-face helmet, step over the side and buckle in.

Aston Martins

New Jersey Motorsports is south of Philadelphia, and its 700-acre facility has two full tracks. The 1.9-mile Lightning road course is extremely fast, with tricked-out 800-hp Porsche Turbos and Aston Martins hurtling down the straightaway at speeds of 160 mph.

The Atom handles like an extreme go-kart: Any twitch of the wheel produces a sizable response, and its tendency to oversteer means that it is eerily easy to slide and spin. I have no intention of being a hero today.

On my third lap, I wheel down a descending right hander and joggle the wheel unsteadily. The back end wiggles and I catch it -- just. Concentrate, Jason. In other cars the electronic stability control would even out my mistakes. Not here. Yet I’ve rarely felt so in tune with a vehicle. Steering is clothesline tight, the brakes are incredibly sure and the acceleration is boggling.

No Insulation

As I blast into the straightaway at 130 mph, the wind buffets my chest and the supercharger churns behind my head. Like a motorcycle, there is no insulation from the road and I’m aware of the speed in a very profound way. I could reach out and touch passing cars.

The six-speed manual is a bit tricky as I’m occasionally unsure what gear I’m in, and the last thing I’d want to do is mistakenly drop from fifth to second. That would mean disaster.

Pulling into pit lane, I’m covered in sweat but am feeling fine. The Atom is a great way to get in touch -- with your fears, abilities and the asphalt itself. Just don’t joggle the wheel unless you mean to.

The Ariel Atom 3 at a Glance

Engine: 2.0-liter supercharged four-cylinder with 300 horsepower.

Transmission: Six-speed manual.

Speed: 0 to 60 mph in 2.9 seconds.

Gas mileage per gallon: 33 mpg on-road (estimated). Price as tested: $85,000.

Best feature: An unbelievable power-to-weight ratio and go- kart-like handling.

Worst feature: Difficult to register for on-road use.

Target buyer: The weekend racer.

(Jason H. Harper writes about autos for Bloomberg News. The opinions expressed are his own.)

To contact the writer of this column: Jason H. Harper at Jason@JasonHharper.com.

Last Updated: October 8, 2009 00:01 EDT