Porsche 911 964 (3rd Generation) Research Hub (1989 - 1994)

964 Carrera 4

The Type 964 911 first launch with an all wheel drive model. It was a serious investment by Porsche in updating the chassis and tech platform. The 964 Carrera 4 was powered by the M64/01 3.6 liter flat six engine, developing 250 bhp and 229 ft/lbs of torque. The objective of the C4’s all-wheel-drive system was not only to provide improved traction but also better handling, especially in the wet and on slippery surfaces. The Carrera 4 model also launched with a Cabriolet version in 1989 (for 1990 model year). The added weight needed meant that both the Coupe and Cab needed ABS brakes and power steering (a first for a 911). In addition to the Coupe and Cabriolet versions, the 964 Carrera 4 had a Targa body style. Only 1,329 of the C4 Targas were sold.

964 Carrera 2

While it was developed alongside the 964 Carrera 4, Porsche waited a year to release the Carrera 2 as a 1990 model year car. It launched with Coupe, Cabriolet and Targa body styles. The rear-engined, rear wheel drive C2 was 220 lb lighter than its C4 sibling was more fun to drive, was sportier and was considered a true successor to the Carrera 3.2 of 1984. The Coupe was (and still is) the enthusiast sports car driver’s choice, while the Targa and Cabriolet were (and still are) popular with those who want their 911 experience with some fresh air. From the outside the Carrera 2 looks exactly like the Carrera 4 other than the obligatory ‘2’ on engine lid versus a ‘4’ for the Carrera 4. Starting in January 1990 the Carrera 2 body styles were available with a new Tiptronic (automatic) gearbox with manual override. Several additional model variants of the C2 came over the following years. In 1992 there was the 964 C2 Cabriolet Turbo-Look (often called the C2 WTL Cabrio), which took the body, chassis, braking system and wheels from the 911 Turbo 3.3. The 964 Speedster came along in 1994.

964 Turbo

The 964 Turbo was the last of the single turbo rear-wheel drive 911 Turbos and was the successor to the famous 930 Turbo. Porsche engineers had been working on a new turbo motor for the 964 but were not fully ready in time for launch of the 964 Turbo. The result was that the 964 Turbo was initially released with the proven 3.3-litre turbo engine from the 930 Turbo. A number of updates improved the engine and power increased to 320 bhp. The 964 911 Turbo had a wider body with significantly more flared wheel housings.

Several improvements to the 964 Turbo lead to the launch of the very special 964 Turbo S. The idea was to combine the 964 Turbo’s straight-line performance with the Carrera RS’s handling characteristics. The Porsche 964 Turbo S Leichtbau was born for model year 1993. Power was up to 380 horsepower (61 hp above the standard Turbo) thanks to thanks to more aggressive camshafts, new injection valves and more boost pressure. The Turbo ended up 400 pounds lighter.

The second generation of 964 Turbo 3.6 launched as a 1993 model year car. The 3.3 liter turbo engine was replaced by a 3.6 liter turbo engine based on the M64 power unit in the 964 Carrera 2 and Carrera 4. Power was up to 360 bhp @ 5,500 rpm and torque was up to 384 ft/lbs @ 4,200 rpm. Other upgrades included better brakes, lower suspension and 18 inch 3-piece Speedline wheels. At the end of 964 production, the Porsche factory had 93 Turbo chassis left. These were all sent to Porsche Exclusiv and built as special 964 Turbo 3.6 S, offered with normal, or ‘Flachbau’ slant nose front ends.

964 RS

In hommage to the 1973 911 Carrera RS, Porsche used the same formula to produce a lightweight version of the Carrera 2 from the race-ready Cup car known simply as the Carrera RS. A primary objective for Porsche engineers was making the 964 RS as light as possible and in the end they were able to take out almost 300 pounds of weight. At 2706 pounds the 964 RS was 286 pounds lighter than the standard model. The RS used an upgraded version (M64/03) of the M64 engine used in the 964 Carrera 2 and 4 (M64/01). Power was boosted by 10 horsepower from the new 3.6 liter boxer engine thanks to some magic by Porsche engineers. Power went from 250 hp to 260 hp and torque increased from 229 ft/lbs to 240 ft/lbs. The chassis was stiffened thanks to additional bracing and welding in key areas. The suspension on the Porsche Carrera RS was lowered by 40mm and made considerably stiffer with race-tuned shock absorbers. The 964 Carrera RS was offered in three road legal versions. The first was a base option that offered no luxury at all, the second, a touring model, came with limited extras and the third was the N-GT (near-production GT).

The original 1973 Carrera RS was available in Europe but not in the USA. Porsche decided to build the 1993 Carrera RS both to European spec and a limited number in compliance with US regulations. These US spec cars were assigned the name “RS America”.

Porsche wanted to race an RSR variant in the GT-category and the result was the car you see here, the Porsche 911 Carrera RS 3.8 (964). The RS 3.8 served as the homologation base for the 3.8 RSR for international competition. Many of its features were borrowed from the 964 Carrera Cup cars. There were two versions; the Sport (or Lightweight) weighed about 10 percent less than the Touring version. Only 55 cars were ever made and they were all special ordered from the factory. Power for the RS 3.8 came from a 3.8 liter version of the M64 motor and was good for 300 bhp.

The rarest 964 RS variant was the awesome 964 C4 Lightweight. Known as the 964 Leichtbau it made use of surplus parts from 953 Paris-Dakar project and only 22 were ever made. The idea was to combine the 964 RS body with the more sophisticated all-wheel-drive system from the 959 while lowering weight. The 964 C4 Lightweight was powered by the same 3.6 liter flat six as the normal 964 RS, but was fettled to produce 300 hp.

964 Race Cars

In 1990 Porsche devised a racing series for the 964 Carrera 2 known as the 1990 Pirelli Carrera Cup Competition and later series such as the Trophie Series and the 1993 Supercup. These cars were completely stripped out for series racing by fitted with aluminum shut panels and a roll-bar system. They were fitted with the M64/03 with a bespoke aluminum intake and a G50/10 gearbox, but almost every system in the car was updated for race preparation. Many of these developments were pushed onto the limited Carrera RS in 1992.

In 1990 and 1991 Porsche made a total of 172 Carrera Cup cars. These were updated to M0001 specification in 1992 with a two-year production of 127 cars bringing the four year total to 299 Carrera Cup cars.

The 964 Carrera RSR reflected Porsche’s return to production-based GT racing dominance. The Carrera RSR 3.8 was an all-out racing car and could be delivered to the track in a race-ready, ‘just-add-driver’ form. The engine of this car was further tweaked and fitted with racing cams, the output varying from 325bhp to 375bhp, depending on track requirements.

Based on the only slightly less-potent RS 3.8, the RSR was a full-bore lightweight Turbo-bodied beast aimed at major European GT contests and the North American Supercar series. The rear of the 911 Turbo’s wide body was occupied by a model-specific Type M64/04 3.8-liter air-cooled flat-six, naturally aspirated with 11.4:1 compression, lighter pistons, dual ignition, new intake manifolds with six individual butterflies, dry-sump lubrication, and Bosch electronic fuel injection. Power was fed through a racing clutch to an uprated five-speed manual transaxle with 40 percent limited-slip.

The Engines

Non Turbo 964 Engines

There are three basic engines used in the non-Turbo 964’s. They are the M64/01, M64/02 and M64/03. The 964 engines were the first produced by Porsche which were the same for all markets, worldwide. All three engines were naturally aspirated, air-cooled or oil-cooled, horizontally opposed (flat), dry-sump lubrication and obviously rear-mounted and all three had a displacement of 3600cc.

The M64 engine is oil and air cooled and, as a consequence, has a lot of oil (11.5 liters) when compared to a more usual water cooled engine. Air is blown over the engine from the main crankshaft driven fan and is also drawn over the engine as the vehicle moves forward. Oil is routed throughpipes along the right hand sill to the front mounted oil cooler which is called into play once the oil thermostat (in front of the right rear wheel) opens. The engine uses a dry sump lubrication system which avoids oil starvation issues in extreme G-force conditions. Using 2 valves per cylinder with a single chain driven overhead camshaft per cylinder bank operating both inlet and exhaust valves via rocker arms, the engine design is heavily based on that of the GT1 racer.

The M64/01 was fitted to the standard Carrera 2 and Carrera 4 models with manual transmissions. The M64/02 was fitted to the Tiptronic-equipped Carrera 2. The M64/01 and M64/02 had 100 mm Bore and 76.4mm Stroke, with a compression ratio of 11.0:1. The M64/03 was fitted to the Carrera RS. It had a remapped engine program and slightly higher compression ratio of 11.3:1 when compared to the M64/01 and M64/02. The result was a bit more horsepower at 260 hp at 6,100 rpm and torque of 229 ft/lbs at 4,800 rpm.

There was also a super rare M64/04 engine used in the Carrera RS 3.8. The engine was known as M64/04. While retaining the same 76.4 mm stroke of the 3.6 liter, the bore was stretched to 102mm, increasing the engine capacity to 3746cc. It also had larger valves, individual throttles and a 11.6:1 compression ratio. In the RS 3.8, the engine produced 300 bhp @ 6100 rpm and torque of 265 ft/lbs @ 4800 rpm. It was further tweaked for the RSR with racing cams and the output varied from 325bhp to 375bhp, depending on the restrictors fitted according to the different class regulations applicable.

Turbo 964 Engines

When the 964 Turbo was unveiled in 1990, Porsche reused the 3.3 liter engine from the Type 930 because it did not have the necessary time to develop a turbo version of the 3.6 liter M64 engine before it released the Turbo variant. A few revisions were made to increase power, but it was basically the same basic engine. Displacement was 3,299 cc.

Power was 320 bhp at 5,750 rpm and torque was 362 ft/lbs at 4,800 rpm. The turbo had less turbo lag than the 930 engine and was different enough that it was designated with its own M30/69 code. A more powerful version of the turbo engine was used in the very limited edition 964 Turbo S 3.3. Power was up from 320 hp to 381 bhp at 6000 rpm with torque of 362 ft/lbs at 4800 rpm.

The 3.6L M64 turbo was finally made available in 1993 and was known as the M64/50 engine. It was a marked improvement over the old M30/69 engine and powered all Turbo 964 models after 1993. The engine had a 3,600 cc (220 cu in) displacement with a 7.5:1 compression ratio. This fine-tuned version of the M64 engine produced an impressive 360 bhp at 5,500 rpm and 384 ft/lbs at 4,200 rpm. A more powerful version of the M30/69 engine was used in the 964 Turbo S 3.6. Power was up 20 hp to 380 hp.