1981 Porsche 928 Twin Turbo

This Porsche 928 Twin Turbo is built based on a 1981 928 with competition package (pre-S car) with the 5-spd LSD transaxle.  Originally turbocharged by a big name 80's tuner on the east cost, the car has been tastefully upgraded to its current status.  The twin turbo system on this vehicle consists of:

  • Ceramic coated twin turbo exhaust manifolds
  • Dual KKK K-26-6 turbochargers from the Porsche 951
  • Dual Tial 38mm Wastegates
  • Ceramic coated downpipes
  • Front mount (single) bar and plate intercooler
  • Porsche 914 1.7 liter fuel injectors with adjustable baseline fuel pressure regulator (1:1 ramp)
  • MAF conversion with signal intercept to allow for fuel maps to be massaged

The engine was fully rebuilt and upgraded with the following:

  • Nikasil plated cylinder bores by Millennium Technologies
  • JE 2618 forged pistons with Goetze ring packs from the Porsche 911
  • All new bearings and seals
  • 1979 Porsche 928 camchafts

The results on this build speak for themselves.  The car has been documented to make near to the 400 wheel HP mark with over 400 ft-lbs of torque on the tire.  These numbers were acheived with just less than 12 psig of manifold pressure.  This coupled with the short rear end gear allows the car to accelerate to 60 in just a tick over 5 seconds with a 1/4 mile measured in the low 13 second range at about 107 MPH.

Built between 2003 and 2005, this example shows that the anemic 928 engines put into the US spec cars can be made into real world performers, even in this day and age.

© 2011 Kuhn Performance Technologies.