Porsche 930 TURBO RESTORATION

PORSCHE 930 TURBO RESTORATION

In December 2018 a customer told us he had an opportunity to buy the parts of a 930 Turbo and whether we would help him rebuild the car.  After looking at the “bits”, we advised he should and we would help him restore the car.  The Turbo arrived in bits on a trailer and the Project commenced…

What exactly is a Porsche 930 Turbo?

The Porsche 930 manufactured between 1975 and 1989 , known as the 911 Turbo, or der Witwenmacher (the Widowmaker) was the fastest production car available in Germany.

The 1975 Turbo powered by a 3 litre engine, total power output from the engine was 256 hp at 5,500 rpm and 243 lb.ft of torque at 4,000 rpm, much more than the standard Carrera it was based on.  Fortified by a  Kühnle, Kopp and Kausch (KKK) blower serving up 0.8 bar of boost meant 0-62mph in 5.5 seconds and 155mph: within spitting distance of the Lamborghini Countach and Ferrari 365 GT4 BB. In order to ensure that the platform could make the most of the higher power output, a revised suspension, larger brakes and a stronger gearbox became part of the package, although some consumers were unhappy with Porsche’s use of a four-speed transmission whilst a five-speed manual transmission was available in the “lower trim” Carrera. A “whale tail” rear spoiler was installed to help vent more air to the engine and to create more downforce at the rear of the vehicle, and wider rear wheels with upgraded tyres combined with flared wheel arches were implemented in order to increase the car’s width and grip, making it more stable.

In 1978 an increase in displacement and addition of an intercooler increased power output and torque, these changes also increased the weight of the vehicle, especially the engine, which contributed to a substantial change in the handling and character of the car compared to the earlier 3.0-litre models. While the increase in displacement and addition of an intercooler increased power output and torque, these changes also increased the weight of the vehicle, especially the engine, which contributed to a substantial change in the handling and character of the car compared to the earlier 3.0-litre models. By cooling the pressurised air charge, the intercooler helped increase power output to 296 hp at 5,500 rpm and 412 N ⋅ m of torque at 4,000 rpm; the rear ‘whale tail’ spoiler was re-profiled and raised slightly to make room for the intercooler and the spoiler was now infamously called the ‘tea tray’ spoiler by the enthusiasts. The suspension benefitted from new anti-roll bars, firmer shock absorbers and larger diameter rear torsion bars. Porsche also upgraded the brakes to units similar to those used on the 917 race car.

The Turbo also walked the talk, of course. The 1978 update brought a 3.3-litre engine and 917-derived brakes. Power leapt to 300bhp, 0-62mph dropped to 5.4 seconds and top speed was 160mph. Even quicker versions followed, including the limited edition 330bhp LE immortalised by Judas Priest, also available in ‘Flachbau’ SE spec with pop-up headlights. Despite its steady evolution, however, the Turbo retained a four-speed ’box until its last year of production in 1989, when the slicker G50 five-speeder was finally introduced.

Our Project car is a 1983 930 Turbo with the 3.3ltr engine and 4 speed manual transmission.  The previous owner has started the rebuild. but clearly the work done was of a poor standard and it was clear that all the parts required to rebuild the car were not present.  So our project began…

Stage 1:

A complete audit of the components and parts with an inventory list produced of good parts, missing parts and parts needing repair.

Stage 2:

The 930 Turbo has been sent for paint.  However, before any paint can be applied we have had to replace both rear quarters along with the front and rear bumpers due to corrosion.

Stage 3:

Now the full preparation works are complete; the paint can be applied, giving the 930 Turbo a new lease of life.  Our customer has stayed original and opted for the timeless classic, Basalt Black!

Stage 4:

Whilst waiting for the freshly painted Porsche 930 Turbo body shell to return to our workshop, we have been busy cosmetically refurbishing the powerful 3.3 litre Turbo charged engine.  Our engine overhaul started by carrying out compression tests which revealed two cylinders low, we traced this to several head bolts found to have failed resulting in the loss of pressure.  The next step was to extract the failed head studs and replace, as required.  Once the head studs had been replaced, we set the tappets to the correct specification.  Now the engine was ready for a general overhaul which included: –

  • Carrying out an inspection on the Turbo, replacing gaskets and sheared clamping bolts where necessary
  • Carrying out a full service, replacing HT leads, spark plugs, sealing rings, push rod tubes
  • Fitting of a complete new exhaust system including heat exchangers
  • Fitting a new clutch and flywheel
  • Replacing corroded tinware where necessary

The engine is now ready to be fitted back into the 930 Turbo!