17" Wheels
 

Were 17" wheels an option on the 90 C2?
The wheels on my car were upgraded by the previous owner to 17".Can I expect any damage to the car over the years as a result of the increased weight and stress? :confused:

Not sure if it was a factory option or not, but 964 series can use 17" without problems, as these were optional in various models. 18" are not approved by Porsche for this series.

As Gus pointed out, 17" runs with no problems (assuming correct offset).

FYI, these were NOT options in 1990 - check out my website for more info at http://members.rennlist.com/complete964

1989 and 1990 964s require the steering stops to be replaced and a minor structural modification to be carried out before installing 17 inch wheels. Failure to do so may and will at normal ride height or when lowered too far,
I enclose the text from the TSB,
Ciao,
Adrian.

Approved 17 Inch Wheel
91porsche03
July 30, 1991
Model Group
911 C2/C4 4
Part Identifier Number
4405 9106
Subject: 17 Inch Wheel Approval
ATTENTION: Service Manager/Service Technician
This bulletin supersedes Technical Bulletin Group 4, Number 9106, dated June 28, 1991.
Models Affected: 911 Carrera 2 and 911 Carrera 4
Concern: Installing 17 inch wheels on 911 Carrera 2/4.
General Information: The following 17 inch rim/tire sizes and tire makes are presently approved for all 911 Carrera 2/4 models.
Tire Size Rim Size Offset Remarks
Front Axle
205/50 ZR 17 7J x 17 AH 55mm
Rear Axle
255/40 ZR 17 8J x 17 AH 52mm No snow chain clearance Note: Rim size 9J x 17 AH ('91 911 Turbo rear axle) is not approved for 911 Carrera 2/4.
Approved tire makes and types:
Bridgestone Expedia S-01 NO Michelin MXX 3 NO Pirelli P700-Z NO Yokohama A-008 P NO
Tire Pressure: Summer tires "17 inch"
Front axle: 2.5 Bar (36 psi)
Rear axle: 2.5 Bar (36 psi)
Note: Tire pressures apply only to Porsche approved tire makes and types. Measure tire pressure only when tires are cold (20~ Celsius or 68~ Fahrenheit). Do not underinflate tires.
Figure 1
Service Information: 1. When installing 17 inch wheels on 911 Carrera 2/4, the steering stop washers, left and fight must be replaced with stop washers Part Number 964 347 325 02 (arrow in Figure 1). Refer to 911 Carrera 2/4 Workshop Manual Volume IV, page 48-3.
Figure 2
2. The bumper cover plastic edge should protrude slightly in the bumper cover to fender joint area. If the fender metal edge protrudes, only the metal edge should be reworked (cut) in the area of the outer mounting screws on the left and fight side to ensure adequate tire clearance (arrow in Figure 2). After cutting metal, apply rust prevention paint.
Parts Information: The following parts are required in addition to the tires:
Wheel rim 7J x 17 Part Number 965 362 124 00
Wheel rim 8J x 17 Part Number 965 362 126 00
(two each required)
Steering stop:Part Number 964 347 325 02 (two required)
Rubber valve:Part Number 900 265 001 50 (four required)
Conversion sets are also available from the Porsche parts department A set consists of:
Four wheels with tires mounted and balanced
Four wheel center hub caps
Two steering stops
Wheel rim cleaner
The following sets are available:
Wheels with Bridgestone Expedia S-01 N0 tires Part Number 000 043 180 00
Wheels with Pirelli P700-ZN0 tires
Part Number 000 043 180 01
Wheels with Yokohama A-008 P N0 tires
Part Number 000 043 180 02

Adrian, I must admit, having those TSBs is proving to be priceless. It will be the first thing I get once I buy the car. Thanks for sharing it with the rest of us. :)

Dear Gus,
I agree that the TSBs are priceless and I wish more repair facilities and parts retailers had them and explained to potential customers about things Porsche. Would certainly help those who run into problems after spending mega bucks doing a simple thing like purchasing a new set of wheels avoid such things like wheel rub. Mind you for 20US dollars you can have them yourself via www.alldata.com
Ciao,
Adrian
911C4
944

Adrian, how do you get them, I searched the site but couldn't find anything. What format do they come in?

regards

Riccardo

[QB]Were 17" wheels an option on the 90 C2?
No. The "Cup-Look" wheels have been option- but they were 16". But don`t worry. PORSCHE allows up to 18" on the 964. Therer are no problems, except teey are to wide.