LAMBORGHINI DIABLO - POWERTRAIN
On its debut, the Diablo came with a 5707cc capacity, with 87.0 x 80.0mm bore and stroke, and a power output of 485bhp at 7000rpm. It also produced 428lb ft of torque at 5200rpm, helping the first Diablo from 0-60mph in 3.9 seconds and on to 202mph. The engine was fitted with Lamborghini's LIE fuel injection, which did little (apparently) to alleviate the average fuel economy of around 14.0mpg.
In 1993, the VT (viscous traction) four-wheel drive transmission arrived and with it came a significantly lighter clutch pedal. This makes VT Diablo models a much better bet for anyone who wants to use their car regularly. Four-wheel drive also helps tame some of the off-the-line traction and cornering foibles of early Diablos, though it also brought more front tyre wear. Hard driving will see the front driveshafts deteriorate quickly, especially with track use, as four-wheel drive Diablos tend towards initial understeer due to the broad rear tyres. The viscous coupling in the four-wheel drive transmission works by sensing the loss of traction at the rear wheels and sending power to the fronts. In extreme conditions, 40% of power can be sent to the front wheels.
With early 5.7-litre VT models, the gearbox's primary driveshaft is not really up to the power of the engine, so look for evidence it has been uprated to a later type. Clutch slave cylinders also fail at around 12,000 miles, while the gear lever itself can snap due to the heavy shift of early cars and weak metal used for the lever in earlier models.
Early Diablos up to 1994 used a hydraulic cam chain tensioner, which continually tightens the chain till it snaps with resultantly expensive bills. A manual adjuster was introduced in 1994 and should have been fitted to most cars as a service item by now, but it's still worth checking. While in the engine bay, Diablos are very sensitive to oil level, so make sure it's at the correct mark and been changed regularly. Oil pumps can fail as a result of low oil level, so keep an eye on this.
In 2000, the 6.0-litre V12 engine arrived with 87.0mm x 84.0mm bore and stroke, upping power to 550bhp. Helping the power gains were a new 32-bit engine management processor, magnesium cylinder heads and variable intake valve timing.
The GTR went further to produce 590bhp thanks to a mutli-throttle intake manifold, titanium con rods in the engine and lightened crankshaft. There was also a bespoke exhaust and reworked engine management to cope with the demands of racing.
Throughout its life, the Diablo was offered with varying power outputs. Notable among these is the SE 30 Jota, which was a factory upgrade for the 525bhp SE 30. The Jota boasted 595bhp for 0-60mph in 3.7 seconds and a 211mph top speed to make it the fastest road-going Diablo ever built.