Cars are packed into the showroom of KTR Racing in Ayer, Mass., a performance shop for vintage racing cars. In the foreground is a Cunningham.

The Providence Journal / Steve Szydlowski

AYER, Mass. Maybe it’s a weather thing.

While relatively common in California, New England shops that specialize in vintage sports cars are pretty rare. Such cars (and their owners) prefer steady sunshine, and certainly do not like rain, snow, salt and grit.

“There aren’t a lot of shops in the Boston area,” said Andrew Funk, general manager of KTR European Motorsports, the division of KTR that specializes in restoring, repairing, tuning and storing vintage race cars here in Ayer. From the outside, the 32,000-square-foot steel box of a facility appears unprepossessing. But a few exotics parked outside hint at the glories within, where KTR is all business with an airy upstairs waiting room its only concession to customer comfort. But then this is a shop for fanatics and it is only open by appointment. A front office gives way to a “showroom/storeroom” so tightly packed with cars it is impossible to get near most of them. But that hardly matters; with such vintage beauties as a 1967 Lamborghini 400 GT, a Maserati Merak from the 1970s, a couple of Porsches – a 993 and a Flat Nose 911 – and a March GTP all in drop-dead condition to drool over, who needs to kick the tires?

But it is in the workshop beyond that the show really begins. Through the door, a vast space reveals all manner of vintage racers in various stages of repair and restoration. A number of low-slung Lotus and Lola racers from England cram one section of the floor, an Aston Martin DB4 sits on the other side, while in the center a stately white 1952 Jaguar KK 120 is raised up and partly stripped. “It was damaged in Pittsburgh at a Vintage Grand Prix when the front end hit hay bales,” said Scott Bertz, general manager of KTR Performance, which services such contemporary European marques as Audi, Mercedes-Benz, Porsche and Volkswagen.

Hang on – damaged in a race? “That’s the beauty of it,” Bertz said. “(These cars) are still raced.”

Indeed, toward the front of the workshop, a 1962 Ferrari 250 GTO was being prepared for the early September Rolex Vintage Festival at Lime Rock Park in western Connecticut. KTR shipped about a dozen cars to that festival. “We bring them down to the track and the owners fly in and race the cars,” said Funk. “That’s all they have to do.”

“(The owners) are a unique group of people, very particular about what they want, very demanding,” he said. “To me, (KTR) is not the corner garage. (We’re) dealing with people who are doing this out of love of the cars. In addition, the racers are very competitive.”

KTR was established about 25 years ago by singer and guitarist J. Geils of the 1970s and 1980s Boston-based rock group, the J. Geils Band, whose biggest hit was ‘Centerfold’ in 1981. Geils had started collecting Ferraris from the 1950s and 1960s and set up the business “mainly to work on his own stuff and help out friends,” Funk said. (The name KTR reflects the names of his three original partners.) Geils sold out to car collector Bob Gett eight years ago, and five years ago the company built and moved to its current facility. “(Geils) still has a little Alfa (Romeo) that he keeps here,” Funk said.

Funk said restoring cars is very expensive, mainly because of the labor involved. But the owners have emotional attachments to the vehicles, he said, and are prepared to spend the money. “Maybe it was their dad’s car or maybe it’s a barn find,” he said. “Maybe they raced it into the ground and parked it somewhere and now have the money to spend on it.”

He said in some cases, the restoration was more of a replacement, recalling a so-called restoration job that the shop did on a Ferrari 275 GTB. “I don’t know if there was a bit of that car that was usable,” he said. And then there is the white Alfa Romeo Zagato that is in an upstairs storage area. “It was a little race car that had been tortured a lot in its life,” he said. “Plus it had been wrapped around a pole. Only a couple of panels were original (after restoration.)”

The shop can manufacture “pretty much any part,” Bertz said, and has a Dyno Dynamics 4WD Low Boy dynamometer to diagnose, test and fine tune engines. It also installs the engines for the Noble M12 and M400, which are very high performance sports cars designed in England. Everything but the engine is manufactured in South Africa and then shipped out to have the engine installed separately.

After 20 years in the business, does Funk have a favorite car? He said it was hard to choose. “I’ve been around these special cars for so many years,” he said. “Ferraris. Their forte was racing and, between styling and performance, that’s a pretty good package there.”

He paused.

“And the outrageous French show cars of the 1930s and 1940s, such as the Talbot Lagos,” he added, referring to high-performance cars noted for their teardrop design.