Guide: Ferrari 408 4RM
Background
Despite having manufactured over 200 different models since 1947, Ferrari do not have a long list of experimental cars that never made it into production.
One such machine was the 408 4RM of 1987.
Ferrari built the 408 4RM with two aims.
First and foremost, it would act as a mobile test bed to explore future production technologies.
Secondly (and more speculatively), Ferrari were keen to procure the kind of consultancy work that helped drive profits at Porsche and Lotus. The Italian firm reasoned that a Ferrari-branded engineering division could rival the best in the business. Accordingly, the 408 4RM was commissioned to demonstrate their state-of-the-art design capability.
As a result, these intriguing prototypes were packed with advanced features like four-wheel drive, electronically adjustable suspension and monocoque body shells.
Chassis
Two examples were completed.
The first (70183) came with a pressed stainless steel monocoque.
The second (78610), and a spare, were formed from aluminium honeycomb chemically bonded together with epoxy resin. The initial aluminium variant was manufactured in collaboration with Canadian firm, Alcan.
Both types came with detachable front and rear subframes and a 2550mm wheelbase. For reference, this was the same length as the Dino 308 GT4 (a mid-engined 2+2).
The longer than normal wheelbase for a pure two-seater was required as the 408 4RM featured a forward-pointing transmission that made it easier to transfer power to both axles. 70% of this was delivered to the rear and 30% to the front giving the 408 4RM unrivalled traction in the Ferrari range.
Suspension was independent all round via unequal length wishbones, coil springs and electro-hydraulically adjustable Marzocchi dampers that enabled ground clearance to be varied from 140mm to 210mm.
Anti-roll bars were installed at either end as were ventilated disc brakes with four piston calipers.
Front track was wider than any other Ferrari of the time. The back end was exceeded only by the Testarossa.
16-inch diameter Speedline alloy wheels had a traditional five-spoke star-pattern design and single centre-locking hub nut. They measured 9 and 10-inches wide front to rear and were shod with Goodyear Eagle tyres.
Engine / Gearbox
Although turbocharging was all the rage in the mid-to-late 1980s, Ferrari stuck with a normally aspirated 90° V8 albeit enlarged from 3.2 to 4-litres.
Mid longitudinally mounted, the dry-sumped dual overhead camshaft all-alloy Tipo 117 power unit was positioned further back than normal so the transmission could be accommodated ahead of the motor.
Ferrari even went so far as to class the 408 as a rear-engined layout.
The Tipo 117 engine was a bored out version of the four valve per cylinder 328 motor. It displaced 3999cc thanks to a bore and stroke of 93mm and 73.6mm respectively. This represented a gain of 10mm and 0.6mm respectively.
Weber Marelli engine management software was adopted along with an unchanged 9.8:1 compression ratio.
Peak output was 300bhp at 6250rpm and 275lb-ft at 4500rpm.
Ferrari installed a five-speed manual gearbox, twin plate clutch and differentials at either end.
Bodywork
As the 408 4RM was never destined for public sale, its boxy and unrefined bodywork was not representative of what a production version may have looked like.
Designed in-house (as opposed to by Pininfarina), the mix of flat surfaces and angular lines gave it a functional rather than beautiful appearance.
Body panels were formed from plastic composite and manufactured at Ferrari's Scaglietti subsidiary in Modena.
The red 408 4RM came with retractable headlights whereas the later yellow example had clear plastic covers.
Front and rear windscreens were heavily curved and the cabin pillars were painted black to lend the glass area a more cohesive look.
Cooling intakes down each flank differed from car to car.
Like the rest of the design, the tail fascia was somewhat bland and did without Ferrari’s trademark lights or grilles.
The rear spoiler featured a speed-sensitive electronic central plane.
Interior
Cockpit access required navigation of wider than usual sills on account of the 408 4RM's monocoque construction.
A properly trimmed interior included new seats with ribbed centres, figure-hugging bolsters and contoured headrests.
The seats were split by a particularly bulky transmission tunnel.
Instrumentation was housed in a small binnacle behind a traditional three-spoke steering wheel.
Subsequent History
As the 408 4RM was created to attract consultancy work, the model was heavily publicised as soon as the first example was completed in June 1987.
However, when long-standing Ferrari engineer, Mauro Forghieri, left later in the year, the consultancy idea was dropped.
Nevertheless the 408 4RM was useful for research and development purposes. Its aluminium chassis technology was adopted twelve years later on the 360 Modena.
Text copyright: Supercar Nostalgia
Photo copyright: Ferrari - https://www.ferrari.com
