AC Frua

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AC Frua
1971 AC Frua
Manufacturer AC Cars
Production 1965–1973
81 made
Class Coupé
Convertible
Engine 7 litre V-8
Transmission 4-speed manual
3 speed automatic
Wheelbase 95 in (2413 mm)
Length 176 in (4470 mm)
Width 68 in (1727 mm)
Height 49 in (1245 mm)
Curb weight 3150 lb (1430 kg)

The AC Frua or AC 428 is a British GT car of the 1960s and early 1970s. Built by AC Cars from 1965 to 1973, only 81 cars were built: 49 coupés, 29 convertibles and 3 with special bodies. The car is built on the AC Cobra 427 Mark III raced bread coil springs chassis but extended by 6 inches. Chassis were built at the AC plant in England then shipped to Frua's workshop in Italy where the body was fitted and then sent back to England to have the power train and trim added. The cost was huge and the cars could not be sold at a competitive price. Unlike similar cars such as the Iso Grifo, Iso Rivolta, and Monteverdis and De Tomasos of the period, the AC Frua features fully independent racing based coil spring suspension. It is often confused with the very similar looking Maserati Mistral also designed by Frua. (There is a common belief that the two cars share most of their body panels, but in reality only the front quarter windows and the door handles are the same.)

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[edit] Construction

1971 AC Frua convertible
1971 AC Frua convertible

Construction was similar to most Italian supercars of that era with square and rectangular tubing connecting the steel body to the frame. There were aluminium bonnets & boot lids. The design was intricate and prone to rust. Because of its huge 4 inch tubular chassis, the car was immensely rigid in both coupé and convertible versions. Chassis numbering went as follows: CF## for cars sold in Britain and CFX## for export models.

1968 AC Frua coupe
1968 AC Frua coupe
1968 AC Frua coupe
1968 AC Frua coupe
1968 AC Frua coupe
1968 AC Frua coupe

The AC Frua was never fully developed because AC Cars lacked the financial means. The car's main drawback, which is also common to the similarly-engined big-block United States muscle cars of the period, is a tendency to dissipate the heat produced by the huge engine into the cabin. But this flow can be overcome by using modern insulation on the firewall and under the floor.

[edit] Performance

The AC Frua competed with Ferrari, Lamborghini, and Maserati models. Built over a stretched AC Cobra 427 chassis, the car had immense performance; the big-block Ford FE engine had larger capacity, more torque and more horsepower than similar Italian cars, but in a car of similar weight.

John Mclellan said in his book "Classic ACs, Auto Carrier to Cobra" that Dereck Hurlock once said to journalist Mike Tailor: " I like the 428 because it fits my image of a true GT Car". He also quoted the magazine Autocar which said the following about the AC 428: "Like anything exclusive, especially from craftmen, it costs a lot of money. For this you get one of the fastest cars on the road, guaranteed to make an impression anywhere, and backed by a small company who cares. This one AC that joined that select company of very fast, very luxurious touring automobiles which moved effortlessly from current model to collector's piece".

Due to the rarity of the car, body parts can be very difficult or impossible to obtain. However, all mechanical parts are available through Ford or various Cobra suppliers. The car is extremely reliable and maintenance is easy and relatively inexpensive compared to other exotics of the period because of the Ford powertrain and AC Cobra suspension and chassis.

With a little tweaking the car can be made as quick as, or even quicker, than a Cobra because of its improved aerodynamics, and the chassis is more than able to handle vast amounts of power. Five hundred horsepower is relatively easy to achieve with the 428 motor and the 427 "side oiler" motor can easily achieve in excess of 600hp on "pump gas" (91 octane). With this type of power the car is one of the fastest road going automobile of that era.

A few of the coupes have been destroyed in the past and converted into Cobra replicas— but as pricing has been rising steadily in recent years, this practice has stopped. It is now much cheaper to buy a Kirkham rolling chassis to build a Exact Cobra replica than to butcher an AC Frua.

AC Frua Technical Data
Chassis "AC Cobra 427 Mark III" four inch tube frame extended by 6 inches. Front engine, rear drive.
Engine Iron "big block" Ford FE 428, some models fitted with higher performance crossover bolted Ford 427 engine (side oiler). Hydraulic lifter, Autolite or Holley four barrels carburator. (Specifications can vary substantially between each car).
Bore & Stroke 104.9 X 101.2 mm, 10, 5:1 compression.
Capacity 428: 7,014 cc, 427: 6,965 cc.
Power 428: 345 HP @ 4,600 rpm, 427: 385 HP @ 5600 rpm (Figures underestimated by Ford for insurance purpose).
Torque 428: 642 Nm @ 2,800 rpm, (462 ft/lb) 427: 624 Nm @ 3200 rpm, (460 ft/lb) (Figures underestimated by Ford for insurance purposes).
Transmission Fully-synchronized 4 speed Ford "Toploader Transmission" close-ratio or 3 speed automatic Ford C6 transmission.
Steering Rack & Pinion.
Front Suspension Fully adjustable independent suspension with double triangular wishbones, coil spring hydraulic telescopic shock absorbers.
Rear Suspension Adjustable independent suspension with double triangular wishbones, coil spring hydraulic telescopic shock absorbers.
Differential Salisbury, limited slip. Ratio: Automatic 2.88, Manual 3.08.
Brakes Four discs power assisted "Girling" 3 pistons, dual remote servo assistance.
Body Coach-built steel body over extruded rectangular and square tubing.
Measurements 4,470 X 1,727 X 1,245 mm; Wheelbase 2,413 mm.
Unloaded Weight 1,430 kg
Maximum Speed Manual Transmission: More than 245 km/h, 0 to 100 km/h: 5.4s (Autosport Magazine); Automatic Transmission: 220 km/h, 0 to 100 km/h 7.5s.
Fuel Consumption 17.2 liters/100 km
Production Life 1965 to 1973
Number of Cars Built 49 coupes, 29 convertibles and 3 special bodied cars.

[edit] See also

[edit] External links

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[edit] Notes