Supercharged 1987 Porsche 928S4


Price: $22,000 OBO


Conact Randy Page at [email protected]

General Information

1987 Porsche 928S4
80,500 Miles
Automatic Transmission
Black Exterior/Black Interior
Option Codes:
CO2:  Equipped with catalytic converter
158:  Radio, Blaupunkt Reno SQR 46 (upgraded, see below)
302:  Type Designation on Rear (was not there when I purchased the car)
418:  Side Protection Mouldings
490:  Sound System (upgraded, see below)
494:  Additional Amplifier (upgraded, see below)
650:  Electrical Sliding Roof (see issues below)

I purchased this car in early 2000 from a gentleman in Charlotte, NC.   At the time, it had around 47,000 miles and was basically stock (just an RMB and turbo wheels).   The car was in excelent condition, it just need a few performance upgrades ;)   After driving the car stock for about a year, I started working on the upgrades that are described below (a five year process).   I did the vast majority of this work myself, with a lot of help from folks on Rennlist, the big three, and especially Tim Murphy.

I have tried my best to accurately describe this car, and have attached a lot of big pictures so you can get a good look at it (sorry if the download is slow.)   I really hate to sell it, but I rarely drive it anymore and could put the funds to better use.

Engine Upgrades

·         Murf Supershark Supercharger Kit

o       Vortech SC polished supercharger.

o       Vortech polished air/water intercooler.

o       Polished aluminum pipes.

o       Vortech polished blow-off valve.

o       Vortech Fuel Management Unit.

o       Custom cooling fans.

·         Bosch rising-rate fuel pressure regulator.

·         Nology spark plug wires.

·         Custom dual exhaust

o       2.5” mandrel-bent pipes.

o       X-pipe with two O2 sensor bungs.

o       2 High-flow CATs.

o       2 Magnaflow stainless mufflers.

o       Chrome exhaust tips (looks similar to 928GT tips)

·         Innovate Motorsports Modular Tuning System LC1 wideband O2 sensor with XD-16 A/F ratio gauge.

o       This sensor is installed in the second O2 bung on the x-pipe, and only powers the XD-16 gauge.

·         Autometer vacuum/boost gauge.

·          Summit liquid-filled FP gauge.

·         Parallel kick-down switch.

·         Powder-coated (almost chrome) parts including:

o       Intake manifold

o       Cam covers

o       Waterpump housing

·         GTS oil pan baffle.

Wheel, Brake & Suspension Upgrades

·         Eibach progressive rate springs and Bilstein shocks.

·         Ott droplinks front and back.

·         Swaybar bushings.

·         Cross-drilled rotors.

·         Stock calipers painted red.

·         Porsche 997 19” wheels (8” front and 11” rear)

·         Continental Sport Contact Tires with about 90% tread remaining (235/35/ZR19 front and 295/30/ZR19 rear)


Interior Upgrades

·         Momo leather steering wheel.

·         Jager shifter and leather boot.


Audio Upgrades

·         Clarion DX2755MC head unit.

·         MB Quart Speakers

o       Front:  Mid range and tweeters fitted into stock locations with crossovers installed in the doors.

o       Rear:   Mid range with tweeters.   Crossovers are installed within the factory openings.  These are located in the back seat area.

·         JL Audio Subwoofer.   I do not know the model number, but I believe it is 8". 

·         Amplifiers:

o       Subwoofer:  Audiobahn A1502DP.

o       Front:   Audiobahn A1004DP.

·         Notes

I replaced all the major audio components less than 2 years ago, however something is not working perfectly.   I purchased all the components new, but there is a bit of a distortion in the sound.    I believe it is related to the wiring, but cannot be sure as I have not really spent the time to debugg this issue.

Other Major Maintenance & Modifications

·         Griffiths Kuehl upgraded A/C condenser (works great.)

o       Running R134

o       Upgraded/replaced all major hoses, o-rings, etc.

o       Replaced expansion valve.

·         GTS teardrop mirrors (heated and electric)

·         Griffiths “HO” power steering pump and rebuilt rack.

o       Also replaced all hoses and the reservoir.

·         Porsche OEM fluid-filled motor mounts.

·         Oil pan gasket.

·         All other major gaskets and hoses including:

o       Intake gasket

o       Cam cover gaskets

o       All hoses including vacuum, radiator, etc.

·         O2 sensor, temp sensors, mass air meter, knock sensors.

·         Rebuilt cruise control unit.

·         Ignition coils.

·         Cooling flaps and motor removed.

·         Tinted windows

·         Heater valve replaced

·         Hood insulation replaced

·         Timing belt and water pump replaced and tensioner rebuilt.

Known Issues

·         Sunroof is currently not working.   I am almost positive that the issue is related to the switch.

·         The front bumper cover has some minor damage, which includes some spidering of the paint.    To be perfect it would need to be repainted.

·         I made a mistake when rolling the passenger side rear fender, and there is a slight bulge in the lip (see pictures.)

·         There are some small rock chips in the hood, but they are all very minor.

·         Minor wear on the driver’s side seat bolster (see pictures)

·         The vacuum diaphragms located in the dash that control the HVAC vents are leaking (the replacements will be included.)   I have temporarily unhooked and plugged the offending vacuum lines so there will be no vacuum leaks.  

·         There are a few minor scratches on the window tint.

·         There is a small chip in the windshield glass (see pictures.)

·         The brake light dummy alarm lights up when the car is first started.   As soon as you tap the brake pedal, it goes out.

·         The brake pad warning light comes on when the car is started.   The brakes are perfectly fine, and I replaced the sensors when I last changed the pads.   I suspect I didn't hook up one of the sensor cables correctly, but have not had time to check this.

Engine Pictures


Exterior Pictures
















Interior Pictures




My Least Favorite Pictures

The pictures below show the aestetic issues mentioned earlier.