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For Sale: 1981 Porsche 928S Auto, White, extensive restoration

Detail

A good example of an earlier model. With the benefits of extensive mechanical restoration (the service history starts here!)

1. Engine disassembled and replaced parts as required. including timing belt, idler assembly and water pump.
2. radiator re cored.
3. External oil coolers fitted with new hoses.
4. Alternator and starter motor overhauled.
5. New brakes, disks and backing plates installed.
6. S-4 slot alloys fitted with new Bridgestone S-02 with N-3 rating.

Interior- dark brown leather in good condition

Exterior- good paint work minimal with minimal discrepancies.

body --cavity wax treated.

Fuel tanks removed and hoses and metal fuel lines replaced.

Flex plate “checked

New battery

The car is a pleasure to drive. I'm retired and don’t need two Porsche's now.

Price £3850 Ono

Click here to contact the seller by email Phone: 01362 688 466

Contents

• Warning - 18inch wheels are not supported on the Porsche 928
• The mysteries of Wheel offsets for the Porsche 928
• Pictures of the standard 928 wheels
• Porsche 928 RDK System
• Installing 17in wheels on 87-91 Porsche 928's

Warning - 18inch wheels are not supported on the Porsche 928

Such damage can occur without warning and the vehicle may become very hard to control or steer as a result of this Improper installation."

Source: Technical bulletin 9305

Offset

I really didnt understand this at all. David Porter created this wonderful diagram that makes it all perfectly clear even to a simpleton like me.

Double click here to get the pdf of it which includes the rears!

What do standard Porsche 928 wheels look like?

1979 Porsche 928 'Telephone Dial'

Porsche 928S

Porsche 928 S2

Porsche 928 S4 - Cast - 7J/8Jx16

Porsche 928 S4 Club Sport - Forged light alloy - 8J/9Jx16

1989 Porsche 928 S4 GT - Forged light alloy - 8J/9Jx16

1990 Porsche 928 S4 GT - Cast Design 90 - 8J/9Jx16

1988 Porsche 928 S4 SE

1995 Porsche 982 GTS - Cup 2 - 7.5J/9Jx17

Spacesaver Spare

Part number from the 1995 Parts list - 965 362 030 00 emergency wheel 5 1/2 J x 16 (offset not mentioned)

Pic: Angus Fox

Winter wheels

Pic:ebay auction (8008930179) With permission from seller klosi001

RDK

While RDK equipped OE wheels are still available from Porsche (in 16" 'flat disc' and 17" 'Cup 1' styles), the expense of these wheels and the unreliability of the system mean that, many owners prefer to fit either replicas or other after market alternatives which are not compatible, and disable the rdk system.

General information on installing 17 inch wheels on 1987 through 1991 928’

1. Front end rear fender well lips must be reworked to assure adequate clearance for tyre travel.
2. All wheel housing components such as brake lines, brackets, etc. must have adequate clearance during suspension travel.
3. The rear tyre pressure for 17” summer tyres is 2.5 bar (36 PSI) at 20% (SW). Rear winter tyre pressure remains at 3.0 bar (44 PSI}. See note on page 2.
4. Snow chains cannot be used with summer tyres, Vehicles with winter tires may use Porsche snow chains, Part Number 911 361 924 00, only.
5. On 1989 928 GT, the distance ring between the wheel and the rear brake disc is not used. .’
   

On 1990 and 1991 928 vehicles with RDK, all of the information above applies, plus this additionat general .information when installing
Porsche 17” tyres and wheels.

1. New tyre pressure sender brackets must be installed. They are Part Number 926 341 087 01 front (2 each) and Part Number
   8,. 928 331 083 01 rear (2 each).
2. When installing 17” Porsche summer tires and wheels, new wheel pressure switches must be installed in the rear wheels. The switches are needed due to the reduced pressure specification. part number for the switch is 928 361 022 00. It is a 2.5 bar switch. Quantity of 4 switches are needed.
3. A new emergency wheel is needed. The original emergency wheel cannot be used once the vehicle has had 17” wheels installed. Part number for the emergency wheel is 965 362 030 01.
4. Once a 1990 or 1991 928 has had 77” wheels installed and all the necessary changes done, it is recommended not to go back to 16in wheels
5. When transferring or installing new pressure switches, always use new seals and torque to proper specification (see Workshop Manual Vol. IV, page 44-31).

NOTE:If 17 inch wheels are installed on the rear axle, the pressure switches are changed to 2.5 bar type. The 3.0 bar type switches should be returned to the customer in the event 17 inch winter tires are to be installed

Porsche say they do not approve 18" wheels on the 928 yet all current Porsche models can be bought with 18" as standard equipment so one suspects that if Porsche was still producing the 928 it would be available with 18" wheels.

One issue with bigger wheels is to remember to decrease the size of the tyres so that the rolling distance of the resulting combination is approximately the same. This ensures that the speedometer, gear ratios, ABS, cruise etc will not be adversely affected by the change.  The table below shows the recommend wheel size / tyres size / tyre pressure combinations for the 928: