EVERY August bank holiday since 1976 the peaceful rural landscape around Colerne in Wiltshire has hummed with the distant sound of growling car engines.

Anyone living on any of the east Bristol commuter routes out of the city will have noticed scores of "racing cars" heading out of Bristol towards Colerne every summer bank holiday Monday.

For more than three decades two of the city's biggest motoring clubs – the Bristol Pegasus Club and the Bristol Motoring Club – have annually joined forces to host a day of timed racing sprints on the wide-open tarmac of the RAF's airfield just outside Colerne.

Yesterday 125 cars of every shape and size lined up at the airfield to take on the challenging 1.75 mile circuit at the 34th Bristol Two Club Sprint.

"It's the best sprinting circuit of its kind in the country," says Martin Baker, the deputy clerk of the course, as he offers to take me for a spin around the circuit between sessions while the competitors are tucking into their sandwiches.

Inside the marshals' Audi saloon car, the flat and seemingly featureless course takes on a new perspective as Martin weaves between the chicanes, grapples with the hairpins, and puts the pedal to the metal for the straights.

"I was only doing about 70mph on the main straight," he laughs, having noticed my alarmed expression.

"Some of these guys in the single-seater cars can be doing anything up to 170mph or even 180mph."

Martin, from Downend, competed in the annual challenge for 15 years, before retiring three years ago to become a marshal and later the deputy clerk of the course.

"It's a lot about reactions, and when you start getting into your 50s, they begin slowing down a bit," he says. "But I wanted to stop while I was on top. In my final year, I won my class, driving my Seat Leon Turbo Diesel. That's what I'd been aiming at for more than a decade, so it seemed like a good time to start putting all my experience to some use and offering to marshal the course instead."

Van driver Nick Wood also has more than a decade of experience of racing the Colerne Airfield circuit each summer.

"I just love it," Nick, from Whitchurch, tells me, as he dusts down the dashboard of his Westfield two-seater.

"As a van driver, I spend all my days out on the roads, so to be able to come out here with my little pride and joy and let my hair down once a year really is great fun.

"I've always been something of a petrol head," Nick admits. "That's why I joined the Bristol Pegasus Club back in the 1990s. There's a real social aspect to being a club member. We regularly meet up to chat about our cars, but the couple of big sprints that we organise really are the highlights of the year.

"As well as the Colerne Airfield day each summer bank holiday, we also meet up for a full day of sprinting at Castle Combe in October each year, when we try to raise some money for the Wiltshire Air Ambulance.

"It's nice to be able to do some good for the charity while we're basically just having a great deal of fun racing around in our cars."

Father and son team Melvyn and Kevin Lealan have taken their passion for racing to the next level.

Kevin says: "I started out back in the 1990s, driving a Westfield like Nick's, but when you get involved one thing leads to another and you tend to work your way up the different categories."

Now the 40-year-old from Frampton Cotterell drives a single-seater Pilbeam MP racing car – complete with Formula One-style cockpit and spoilers.

Dad Melvyn, 67, has become Kevin's trackside engineer.

"It is a real father and son team," Kevin says. "I run a motor spares company in Yate, so for me this is a bit of a busman's holiday, but it's great fun.

"I used to take part in lots of different rallies when I was younger, and I suppose Kevin grew up watching me racing, and gradually he got the bug himself.

"This is a serious racing car he's driving now. It's a two-litre Vauxhall 16-valve engine in there, pushing out 318 brake horsepower in a car that weighs only 450kg, so the weight to power ratio makes it quite a powerful motor car.

"I wouldn't like to say how much we've spent on it over the years, but it is a big investment, both in terms of money and time. But it's more than worth it."

Kevin came sixth in the national sprint championship last season, but today he's not having such a good time.

"The car's been playing me up today," he admits with a shrug of the shoulders. "But that's how it works. You have good days and bad days on the circuit.

"But however you're performing out there, it's always great fun to be around so many like-minded petrol heads. For me, this is what bank holidays are all about."