Costin-Nathan Imp

based on a letter by Rod Hunt in Impressions, June 1986

Roger Nathan had made a name for himself in the early sixties racing Lotus Elites and then set up in business developing tuning kits for Imps.
In 1965 he colaborated with Frank Costin in the design and development of an Imp engined sports-racing car.

Frank Costin is the well-known aerodynamacist responsible for the design of many early Lotuses, the Grand Prix Vanwall and the Costin-Amigo. He is the brother of Mike Costin, the 'Cos' in Cosworth and is of course himself the 'Cos' in Marcos.

The Costin-Nathan was based on a monocoque centre-section made of resin-bonded plywood (as is expected from the Marcos designer...) with front and rear frames made from steel tubing.
The Imp engine was mid-mounted and angled in the chassis at 54 degrees to the right - a revised lubrication system being necessary for this installation. The gearbox was an Imp unit with close ratios mounted upside-down. On the prototype the body was an open two seater but later models were coupes with typically Costin rounded aerodynamic bodies.
The cars were raced largely in Britain in 1966 and 1967. In '66 Nathan raced the open car six times and won his class five times and was second once. He also set five new class lap records.

based on Wedstrijdsportwagens, deel 2 / Hans Peters. - 1967

	Racing Car Show 1967 The Costin-Nathan sports prototype - new £2150 Behind it stands the topless Nathan Imp

The car made its debut at Brands Hatch in April 1966. Roger Nathan tuned the Imp engine and Frank Costin provided the expertise in aerodynamics.

The central section of the chassis is made of plywood, treated with resin. At the front and rear tubular frames are bolted to the wood with six bolts each. This has the advantage that, in case of misfortune, one of the frames will remain undamaged - which saves costs. The chassis is strong enough for engines up to 350bhp.

The tubular wheel conductors are of unequal length.
It has anti-roll bars both at the front and the rear.
The 13" magnesium wheels have 6" rims, 7" on the back. Girling disc brakes (with AR pads up front and NR pads on the rear), with a disc diameter of 241,3 mm. Race tyres by Dunlop, MK II 5.00x13 R7 on the front wheels, 5.50 on the rear ones.

The bodywork is made entirely of fibreglass. The hinges are on the front side of the doors -- earlier models had them at the rear, which was prohibited by 1966.

Someone in Kent is in the proces of restoring an Imp-engined Costin-Nathan. (1998-1999)

Someone in Sydney (a gentleman called Bruce ...) is rebuilding a Costin Nathan with Imp power. (He races Lotuses) - according to Dave in Oz on Sat Jul 26, 2008 on the Imp Club Forum

Roger Nathan standing next to a BMW-engined Costin Nathan.

Costin Automotive Racing Products ltd., Little Staughton, Beds. (1971-1972)

Nathan GT

Silverstone Test Day : Falcon, Anglia, Berpop, Nathan GT / by Jeremy Walton; driving: Steve Neil; photos: Max Le Grand. - Cars and Car Conversions 1969, Feb. - 147-149
This and future articles, which will deal with each car in more detail.

To try four of the cars that entertained us during '68, amongst them Roger Nathan's 998cc Imp GT. The yellow Motoring News Championship winner was the best prepaired and quickest around that day. Roger used his Nathan GT in the latter part of the '68 season. It was easiest to drive and could outcorner and outbrake all the balloons. Top speed on the long straight was around 120 mph.

• What makes them go (or why didn't they go, when they should have)
• A professional racing driver's thought, just after he'd driven them
• A chance to insert a journalist in the sweat seat, to tell you all how it is in there.