LightWeight Confusion

Lightweight Carrera Confusion – Second Edition

This article is a revision of my article ?Lightweight Carrera Confusion?
which appeared in the May 1993 edition of Porsche Panorama, the monthly
magazine of the Porsche Club of America,

For Europe in model
year 1992, Porsche produced a lightweight road version of the Carrera 2 called
the Carrera RS which was available in 3 variants for road use and also a for
racing only fourth variant, the Carrera Cup racing car.

For the United States and Canada in model year 1992, Porsche produced the
limited production Carrera Cup USA Edition and introduced the RS America, both
of which are also lightweight road versions of the Carrera 2.

This article will discuss the history and differences between the normal
Carrera 2 and these lightweight Carrera 2 cars.

The 1992 European Carrera RS

Porsche has a long history of developing and selling special performance
versions of their normal product line for both street and racing use. Of these
cars the Carrera RS versions of the 911 are probably the most famous. The first
of the Carrera RS cars was introduced in 1972 when Porsche introduced the
Carrera RS 2.7 lightweight as a homologation basis for a GT racing car, the
Carrera RSR 2.8. These cars were extremely successful both on the sales room
floor and at the racetrack and ultimately evolved into the Carrera RS 3.0 road
cars and Carrera RSR 3.0 racing cars. Porsche did not import RS 2.7 and RS 3.0
road cars to the USA.

Twenty years later during model year 1992, history repeated itself when
Porsche developed a special performance version of the 1992 Carrera 2 called the
Carrera RS, again not imported to the USA.

The 1992 Carrera RS was conceived primarily as the basis for a competition
vehicle to be used for FIA Group N (large series production based touring cars)
or FIA Group GT (Grand Turismo) racing, as well as a basis car for the factory?s
popular Carrera Cup racing series.

In creating the 1992 European Carrera RS, every component of the 964 Carrera
2 suspension, braking, and power train systems was changed in the interest of
higher performance. Porsche extensively applied design features used in the 172
Carrera 2 based Carrera Cup racing cars produced for the 1990 and 1991 racing
seasons.

There were three M optional versions based on the so called: ?Carrera RS
Basic? offered in model year 1992:

Carrera
Cup Vehicle, option M001
Carrera
RS ?Touring?, option M002
Carrera
RS ?Competition?, option M003.

The RS Basic, M002 and M003 types were approved and sold
for
road use around the globe for model year 1992 only, excepting the
USA.

The M001 Carrera Cup racing car was not approved for
road use
anywhere and was built for racing customers only using the 964 RS
chassis in both model years 1992 and 1993.

The 1992 Carrera RS Basic and M002 Touring cars have VIN
numbers with a 9 series thirteenth digit (9= Carrera RS) reserved for them in
the range: WPOZZZ96ZNS4 9 0001 to 2500.

The 1992 M003 Competition versions have VIN numbers with 99
as the thirteenth and fourteenth digits reserved for them in the range:
WPOZZZ96ZNS4 99 001 to 300

The 1992 M001 Carrera Cup
racing cars built have VIN numbers with a 9 as thirteenth digit and an 8 as the
fourteenth digit reserved for them in the range: WPOZZZ96ZNS4 98
001 to 150.

In 1992 Porsche built 2282 road cars distributed as:

1916 Basic version cars (including 72 right-hand
drive).
76 Touring version M002 cars (including 11 right-hand
drive).
290 Competition version M003 cars.

In 1992 Porsche built 112
M001 Carrera Cup racing cars.

The 1993 M001 Carrera Cup racing cars are in the ?P? series
VIN range WPOZZZ96ZPS4 98 001 to 999.

I have no data on the number of Carrera Cup cars produced
in 1993. No Carrera RS Basic, M002 or M003 cars were built in 1993..

Engine serial numbers for all 1992 RS
variants are in the sequence 62N80001 to 62N 90000, 1993 Carrera Cup cars have
engines in the range 62P80001 to 90000.

Gearbox serial numbers for the type G50/10
gearbox for all types are in the sequence starting: G5010 2 000001.

The RS America

The RS America was introduced in 1992 as a performance
oriented lower cost alternative to the regular Carrera 2. All RS America’s are
technically 1993 and 1994 cars, even though production of the cars actually
began in January 1992.  August is the usual month when Porsche does its new
model change over and the month when the other model year 1993 Porsches began
production.

The RS Americas built between January and August 1992, a
total of 294 cars, have VIN numbers in the 1993 “P” series range, with a 1
series (1=RS America) thirteenth digit and an 8 as the fourteenth digit reserved
for them in the range: WPOAB296?PS4 1 8001 to
8293.

RS Americas built after August 1992 have VIN numbers in the
sequence with a 9 as the fourteenth digit reserved for them in the range:
WPOAB296?PS4 1 9033 to 9368 (335 cars).

RS Americas built after August 1993 have VIN numbers in the
1994 ?R? series cars with numbers in the range: WPOAB296?RS
1
9067-9139 (72 cars).

The ??? in the USA VIN Number indicates a randomly
generated number which can be the numbers 0 through 9 or the letter X in the
United States only.

Engine serial numbers for the first 294 cars are in the
1992 “N” series range, 62N 00001 to 20000. Engine Serial numbers for cars built
after August 1992 are in the 1993 “P” series sequence 62P 00001 to 20000 and
engines built after August 1993 are in the ?R? series sequence 62R 00001 to
20000.

Gearbox serial numbers for the G50/05 type gearbox for all RS America cars
are in the normal Carrera 2 sequence G 5005 1 000001 without LSD or G
5005 2 000001 with LSD option M220.

Total production was 701 RS America cars. The RS America was offered for sale
in the USA and Canada only.

The Carrera Cup USA

In the early 90?s Porsche instituted a very
successful racing series in Europe called the Porsche Carrera Cup. The Carrera
Cup at the time was a racing series featuring specially factory modified 911
Carrera 2?s running as a support race during Formula 1 race weekends like the
Porsche Supercup series today.

In 1992 Porsche Cars North America (PCNA),
hoping to emulate the success of the International Race of Champions (IROC)
races of the early 1970?s, sought to develop a Carrera Cup series in the USA.
The plan was that teams would pay around $100,000 for a car specially prepared
for a USA Carrera Cup racing series that would support professional races here.
As in Europe, no further modifications to the cars were to be allowed except for
wheel alignment, wheel weighting and sway bar adjustment. The engines were to be
sealed so that internal modifications were not possible. All teams were to use
Toyo tires. The Motronic engine management brains for each race were to be
handed out to the teams by the organizers before each race and then collected
after each race. Now all that was needed for this plan to work were racing cars
and teams that would buy the cars and race them.

Production of a suitable racing car for the series turned out to be a little
tricky. The simple solution car would have been for Porsche to build a run of
Carrera Cup cars for the series and import them as was done with the IROC
Carrera RS 3.0 based series cars in the 1970?s. I have been told that this was
not feasible in 1992 because of some trouble Porsche found itself in during the
1980?s with the US Federal Government after Al Holbert, then director of Porsche
motorsport activities in the USA, imported some European Porsche 959 cars as
?racing cars?. When the Environmental Protection Agency and Department of
Transportation decided that the 959?s were more likely to end up on the street
than on a racing track they were impounded and sent back to Germany. Porsche was
put on notice that any ?racing car? that ?looked like? a street-type car had to
meet EPA and DOT laws. PCNA was sensitive to the fact that anything they import
may be sent back to Germany by the US Federal Government if it didn?t meet
federal regulations.

At the time the 1992 964 Carrera RS served as the basis car for the European
Carrera Cup, just as the 996 GT3 serves as the basis car for the Supercup series
today. Therefore, for the proposed USA Carrera Cup, PCNA asked Andial/PMNA to
coordinate with Porsche AG a limited production run of USA legal cars similar to
the European Carrera RS. Andial/PMNA would then be contracted to convert these
road legal cars to Carrera Cup racing cars for the racing series. Forty-five
?Carrera Cup USA Edition? cars were specially produced and sent to the PCNA port
in Charleston, W. Virginia.

Twenty-nine of these 45 cars were shipped from Charleston to Andial/PMNA. Of
these, 25 were converted to the full Carrera Cup racing specification and 4 had
their engines sealed, checked on the dynamometer and their clutch plate changed
to the racing unit. These 4 cars were to be used as parts cars and were
otherwise unchanged from the way they were imported. These 29 cars were then
shipped to Reno, Nevada for storage at Porsche Cars North America.

The cost of producing racing specification cars in this way was high and PCNA
tried to pass on this cost to racing teams, so finding enough teams to buy and
race the cars proved impossible. In addition the weak American economy in 1992
reduced the hoped for sponsorship support and the series was cancelled by PCNA
before it began.

After the Carrera Cup USA series cancellation, the 29 racing and modified
cars were returned to Andial and reconverted back to their original street legal
specification as originally imported. The only remaining elements of the
conversion are 2 tubes left from the roll cage on each side of the engine
compartment, remnants of the roll cage weld pads inside the car and the stiffer
steering coupler links were also left in the cars. The cars were then shipped
from Andial back to the Porsche port in Charleston, South Carolina for final
carpeting and paintwork before shipment to dealers.

Sixteen of the original 45 cars were never shipped from South Carolina to
Andial in the first place and were sold as they were imported.

Probably since PCNA was sensitive about the cancellation of the racing series
there was no national advertising program about the cars availability other than
a letter to Porsche dealers. All 45 cars were sold quietly through the regular
dealer network as a model officially called the Carrera Cup USA Edition.

The cars were delivered with a dash plaque indicating each cars VIN number
and their Carrera Cup USA Edition status. The 25 cars that were converted by
Andial/PMNA to full race specification also have a separate sub-serial number
engraved on their dash plaques numbering them from 92-01 to 92-25 (92 for the
year 1992, 1-25 for the cars conversion sequence).

Carrera Cup USA Edition cars have standard USA Carrera 2 VIN numbers with a 2
series thirteenth digit (2=Carrera 2) in the range: WPOAB296?NS4 2
XXXX, where ?XXXX? represents the serial number of the chassis.

The USA Carrera Cup edition cars were built non-consecutively on the
production line and have serial numbers ranging between 0392 and 0602,
inclusively. Serial number 0392 was a pre-production car. Production really
began in earnest with serial number 0509 so, during the actual period of
production, approximately every other car on the production line between 0509
and 0602 was a Carrera Cup USA car.

Gearbox and engine serial numbers are in the identical range as the European
Carrera RS cars shown above.

Comparing the Bodywork

Bodywork Comparison

Table 1


 


 


92/93
Carrera 2

 


93 RS
America

 


92
Carrera RS Touring

 


92
Carrera RS Basic

 


92
Carrera Cup USA

 

Spoiler

 

 

 

Retractable

 

Fixed

 

Retractable

 

Retractable

 

Retractable

 



Side
Mirror

 

 

 

Electric Adj.

 

Manual

 

Electric Adj.

 

Manual

 

Manual

 



Front
Hood

 

 

 

Steel

 

Steel

 

Aluminium

 

Aluminium

 

Aluminium

 



Glass
Type

 

 

 

 

Standard

 

 

Standard

 

 

Thin

 

 

Thin

 

 

Thin****

 



Rear
Bumper

 

 

 

 

Euro or USA
Standard

 

USA Type

 

Euro RS

 

Euro RS

 

USA Type

 


Door
Beams

 

 

 

Yes

 

Yes

 

No

 

No

 

Yes

 

NGT Racing Seamwelds Etc.*

 

 

 

No

 

See Text

 

See Text

 

Yes

 

Yes

 



Rolled
Finder Lips

 

 

 

No

 

No

 

Yes

 

Yes

 

Yes

 


Interior Sound Dampening

 

 

 

Yes

 

Reduced

 

Yes

 

No

 

No

 


Undersealing

 

 

 

Yes

 

Yes

 

Yes

 

No

 

No

 



Rust
Warranty

 

 

 

10 Years

 

10 Years

 

10 Years

 

3 Years

 

3 Years

 



DIN
720020 Weight

 

 

 

 

 

 

 

 

 

 

 

 

 

Kilograms


K G

 

11 1377
USA  13111325  Euro

 

1343

 

1320

 

1220

 

No Spec.

 


Pounds

 



LBS

 

3031 USA

2970 Euro

 

2954

 

2904

 

2684

 

2835*

 


Fog
lights

 

 

 

Yes

 

Yes

 

False Lights

 

False Lights

 

Yes

 


Windows

 

 

 

 

Electric

 

 

Electric

 

 

Electric

 

 

Manual

 

 

Electric

 



Cruise
Control

 

 

 

Yes

 

No

 

No

 

No

 

No

 


Central Locking & Alarm

 

 

 

Yes

 

Yes

 

Yes

 

No

 

Yes

 



Wiring
Harness

 

 

 

Standard

 

Standard

 

Standard

 

Simplified

 

Standard

 

Battery

 

 

 

75 AH

 

75 AH

 

72 AH

 

36 AH

 

36 AH

 

 

Master Electrical Switch in Trunk

 

 

 

No

 

No

 

No

 

Yes

 

Yes

 


Interior Lighting

 

 

 

Yes

 

Yes

 

Yes

 

No

 

Yes

 



Heated
Rear Window

 

 

 

Yes

 

Yes

 

Yes

 

No

 

No

 


Windshield Cleaner Capacity

 

 

 

7.4 ltr.

 

7.4 ltr.

 

7.4 ltr.

 

1.0 ltr.

 

7.4 ltr.

 

Airbags

 

 

 

Yes (USA only)

 

Yes

 

No

 

No

 

Yes

 



Front
Seat

 

 

 

Basic

 

Sport

 

Sport

 

Bucket

 

Basic

 


Rear
Seat

 

 

 

Folding

 

Pkg. Tray W/2 doors***

 

Carpet only

 

Carpet Only

 

Pkg. Tray W/O Doors

 

Carpet type

 

 

 

Standard

 

Lightweight

 

Lightweight

 

Lightweight

 

Lightweight

 


Door
Panel

 

 

 

 

Standard W/Pocket

 

Lightened Pull Strap type

 

Standard W/ Pocket

 

Lightened Pull Strap type

 

Lightened PullStrap type

 


Front
Trunk Carpet

 

 

 

Complete

 

Complete

 

Complete

 

Shortened

 

Shortened

 

 


Fuel
Tank Capacity**

 

 

 

77 litre

 

77 litre

 

92 litre

 

92 litre

 

77 litre

 


* See
text


**The
larger fuel tank holds approximately 25 pounds more fuel, which is
included in the vehicle weight indicated.

 


***
The RS America had standard rear seats in model year 1994

****The Carrera Cup USA car had standard rear glass due to the centre high
mounted stop light installation. Door glass was of the thin type.

 

Table 1 offers a
comparison of variations in the bodywork, Interior trim, and electrical
equipment.

Note that the USA Carrera 2 is heavier than the European
Carrera 2 due to the addition of the 5-mph bumper system, airbags and
air-conditioning that are standard for the USA.

The RS Basic

The Carrera RS Basic utilizes the standard European Carrera
2 body with a retractable spoiler. Weight is saved by deleting Carrera 2
standard equipment such as, radio (the windshield antenna and basic wiring are
retained so a radio could be fitted if required), cruise control, electric
window lifts, central locking and alarm, interior lighting, electric mirror
adjusters, fog lights (replaced with dummy lights), rear window defroster wiring
and relays are all deleted to save weight (the rear widow does have heating
elements on the glass but they are not activated since the battery is only 36
AH)

The Carrera RS Basic interior is lightened by the use of
lightweight carpeting which also replaces the seats in the rear, lightweight
door panels, fibreglass bucket seats, simplified trunk carpeting (which only
covers the spare tire) and a simplified plastic cover for the forward trunk
bulkhead. Further weight is saved by use of a simplified wiring harness, an
aluminium hood, a small 36 AH battery, thinner (3 mm versus 4.7 mm) glass and a
1 litre windshield washer tank. Interior sound dampening in what would be the
rear seating area is deleted. A larger 92 Litre gas tank is fitted. The rear
bumper all the European Carrera RS variants is a unique 11 pound lighter
design.

Many changes are made to the body shell of the Carrera RS
Basic to make it suitable for N/GT and Carrera Cup racing. For those of you
interested in the complete scope of the changes, refer to the Carrera 2/4
Workshop Manual, Body Volume V, pages 50-101 to 53-104.

Briefly, these modifications include:

1) Installation of mounts for:

       Master electrical switch above the battery
1-liter
windshield bottle in trunk
Electro-hydraulic brake system
       Alternate mounting bracket for the ABS brain above
the original location.
Front
tow hook
Smaller
36-AH battery
Fire
extinguisher
Inertial reel covers for the front seat belts
Six-point harness restraints

2) Seam welding and plating of the rear suspension mounting
points, rear floor area, transmission and stabilizer mounts,

3) Removal of rear seat brackets, seat belt mounts, and
trim brackets. .

4) Fender lips rolled for tire clearance front and rear.

Undercoating is deleted on the RS Basic so it only has only
a 3-year rust warranty.

The RS Basic weighs 2684 pounds (including approximately 25
pounds more fuel in the 92 litre fuel tank compared to the normal 77 litre
tank).

The Carrera RS Touring M002

The M002 Carrera RS Touring?s bodywork is different than
the RS Basic. The interior is largely the same as the standard Carrera 2 with
the usual Carrera 2 door panels that include radio speakers and pockets. Sound
dampening is used in the rear seating area but seating is replaced with carpet
as on the RS Basic. Sport seats, usually optional on the Carrera 2, are standard
and replace the fibreglass buckets of the RS Basic. Front trunk carpeting and
trim are as a standard Carrera 2. Other equipment is included such as alarm and
central locking systems, interior lighting, 72 AH battery, 7.4 litre windshield
washer tank, power windows, antenna amplifier, 92 litre fuel tank and an
operable heated rear window.

The extents of the bodywork modifications cited above for
the Basic car in the factory manual are limited in the M002 Touring car. Certain
operations such as removal of some interior brackets, installation of 6-point
harness mounts, alternate location of the ABS brain, provision for a smaller
battery and installation of the trunk mounted battery switch and smaller
windshield washer bottle were not performed on the Touring RS car. The Touring
RS also has undercoating and a 10 year rust warrantee.

The RS Touring weighs 2904 pounds (including approximately
25 pounds more fuel in the 92 litre fuel tank compared to the normal 77 litre
tank).

The Carrera RS Competition M003

The M003 Competition option included the following
modifications to the RS Basic:

  1. Deletion of interior carpeting, headliner and A/B pillar
    covering.
  2. Painting of interior to match exterior colour.
  3. Shortened knee padding on lower dashboard to clear roll
    bar installation if ordered.
  4. Driver’s side sun visor only.
  5. Provision to unlock trunk and fuel door from drivers seat
  6. Engine compartment insulation deleted
  7. Six point seat belt for driver and passenger.
  8. DME Brain box moved behind drivers seat (standard
    location under seats in way of crotch belts mounts).
  9. Hand held fire extinguisher mounted on passenger floor.
  10. Cable activated master switch from inside of car
  11. Recaro SPG bucket seats for passenger and driver.

All the European RS cars have a “Carrera RS” emblem on the
deck lid, which is also optionally available on the side of the car as script
along the door bottoms.

The RS America

The RS America deletes the usually standard, in the USA,
Carrera 2?s air conditioning, radio, sunroof, electrically adjustable mirrors
and cruise control to reduce weight and cost. The rear spoiler is a fixed,
non-retractable ?tray? type as on the earlier 3.2 911 Carrera.

In the RS America a simplified lightweight interior uses
the RS Basic door panels but with radio speakers installed and a lightweight
interior carpeting material used. Front seats are cloth covered sports seats.
The rear seats, trim, rear radio speakers are eliminated and replaced with
carpeting and, for the model year 1993 cars, a package tray that has doors to
seal the storage areas below it. Model year 1994 RS America cars had the same
rear seats as standard Carrera 2.

On the deck lid ?RS America? script appears and “RS” is
written on the sides of the car ahead of the rear wheels

It is not clear how many of the body modifications of the
European Carrera RS have been carried out on the RS America. The earliest cars
had basically the same body modifications as a European RS Carrera Touring car.
Later cars did not have the rolled fender lips rolled. I think this change
probably happened after August 1992 when the factory stopped production of the
European RS car.

The RS America weighs 2954 pounds

The Carrera Cup USA Edition

The Carrera Cup USA Edition car is essentially the European RS Basic but
equipped with the following added safety equipment to make the car USA legal
along with some other changes to facilitate it?s ultimate conversion to an M001
Carrera Cup racing car:

  1. Airbags (legal requirement)
  2. Centre high mounted stop light with associated thicker
    rear window glass (legal requirement)
  3. USA 5 mph bumpers (legal requirement)
  4. A door-less rear package tray (Porsche apparently does
    not want the seat pockets remaining in the rear to potentially be used as
    seating without seatbelts),
  5. Standard seats (to be replaced with a racing seat)
  6. Alarm and central locking system (legal requirement,
    Porsche chooses this rather than stamping numbers on body parts)
  7. A 77 Litre gas tank (92 litre not approved for USA)
  8. Power windows (manual windows winders won’t clear the
    airbag dash padding)
  9. Interior lighting (part of American wiring)
  10. Fog lights (part of 5 mph bumper)
  11. A 7.4-liter windshield washer tank (no support for 1
    litre bottle in USA harness)
  12. Standard USA wiring harness (required to support the
    added electrical equipment)
  13. Deck lid and sides are free of any model designation.
  14. Aluminium 7 and 8 X 17 inch wheels as on RS America
    (Aluminium 8 inch rear wheels were needed for the front in the Carrera Cup
    racing conversion)
  15. Deletion of emblem script on deck lid.

The Carrera Cup USA body was created using a so-called
?body in white? as for a USA airbag equipped car and performing the workshop
manual operations listed above for the European Carrera RS Basic. Three of the
operations listed in the workshop manual were not performed though: adding the
bracket for the small water bottle, deleting the bracket for the large water
bottle and removing the brackets for the rear seats.

Carrera Cup USA car serial number 0392, the pre production
car, is slightly different from the 44 other cars in that it had the bracket for
the small RS water windshield washer water tank installed and had the brackets
for the rear seating removed. The carpeting was also tightly glued down.
Subsequent cars did not have the water bottle bracket, the rear seat brackets
were not removed and the carpeting was barely glued into the car to facilitate
removal when the car was converted to a racing car.

All Carrera Cup USA Edition cars were white excepting one
India Red car, thought to be dedicated as the series pace car.

The Carrera Cup USA has no official weight quoted for it,
although a letter to dealers claimed “approximately” 2760 pounds. My Carrera Cup
USA with all fluids weighed 2835 pounds on a certified truck scale.

Comparing the Cars Mechanically

The Suspension System

Table 2


Front Suspension


Component

 


92/93 Carrera 2

 


93 RS America

 


92 Carrera RS Basic, M002 and M003

 


92 Carrera Cup USA

 


 


 


 


 


 

Stabilizer Diameter

 

20mm

 

22mm

 

24mm, 5 way adjustable

 

24mm, 5 way adjustable

 


Spring
Rate

 

Base Rate

 

Base Rate

 

Higher Rate

 

Higher Rate

 


 

 

 

 

 

 

 

 

 

Damper Type

 

Boge

 

Boge HD

 

Bilstein

 

Bilstein

 

Hub Material

 

Steel

 

Steel

 

Aluminium

 

Aluminium

 


Upper
spring strut mount

 

Rubber

 

Rubber

 

Ball Joint

 

Ball Joint

 


Lower
Control Arm Bushings

 

Standard

 

Standard

 

Harder
Rubber

 

Harder
Rubber

 

Ride Height

 

Std. USA*

 

Std. USA

 

50mm Lower

 

50mm Lower

 


Camber
Setting

 

0°±10′

 

0°±10′

 

-1°±10′

 

-1°±10′

 


 

 

 

 

 

 

 

 

 

Wheels

 

6?x16?

 

7?x17?

 

7.5?x17?

 

7?x17?

 

Offset

 

52mm

 

55mm

 

55mm

 

55mm

 

Material

 

Aluminum

 

Aluminum

 

Magnesium

 

Aluminium

 


 

 

 

 

 

 

 

 

 


Tire
Size

 

205/55

 

205/50

 

205/50

 

205/50

 

Steering

 

Power

 

Manual

 

Manual**

 

Manual

 

 

 

 

 

 

 

 

 


Rear Suspension Component

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Stabilizer Diameter

 

20mm

 

20mm

 

18mm 3-way adjustable

 

18mm 3-way adjustable

 


Spring
Rate

 

Base Rate

 

Higher

 

Highest

 

Highest

 


 

 

 

 

 

 

 

 

 

Damper Type

 

Boge

 

Boge HD

 

Bilstein
Single Tube

 

Bilstein
Single Tube

 


Upper
Spring Strut Mount Design

 

Rubber

 

 

Rubber

 

Ball Joint

Ball Joint

 

Trailing Arm Control Mount

Standard

 

Standard

 

Modified

 

Modified

 


 

 

 

 

 

 

 

 

 


Ride
Height

 

Std.*

 

STD USA*

 

40mm Lower*

 

40mm Lower*

 


Camber
Setting

 

-0.5’±10′

 

-0.5’±10′

 

-1º15’±10′

 

-1º15’±10′

 


 

 

 

 

 

 

 

 

 


Wheels

 

8?x16?

 

8?x17?

 

9?x17?

 

8?x17?

 

Offset

 

52mm

 

52mm

 

55mm

 

52mm

 

Material

 

Aluminium

 

Aluminium

 

Magnesium

 

Aluminium

 


Tire
Size

 

225/50

 

255/40

 

255/40

 

255/40

 

 

 

 

 

 

 

 

 

*US
ride height 10mm higher than European, so RS/Cup USA 50 mm lower than USA
cars

 

**
Power Steering Optional on RS Touring. Standard on all RHD RS cars

 

Table 2 shows the RS America suspension
is the same as that optionally available on the standard Carrera 2 as option
M030; changes consist of a larger front stabilizer bar, stiffer 911 Turbo
progressive rear springs and firmer 911 Turbo shock absorbers.

Porsche changes essentially every component of the standard
Carrera 2 suspension to create the Carrera RS and Carrera Cup USA suspension.
The suspension of the Carrera Cup USA and the Carrera RS is considerably firmer
that that of the RS America. Firmer Shock absorbers and stiffer progressive rate
springs are added at all four corners. The front stabilizer is adjustable to
tune handling to driver preference. To reduce camber change in the front
suspension during cornering, harder suspension bushings are used in the lower
control arms and the upper spring strut mount is of a ball joint design. To
reduce weight, steel front hubs are replaced with aluminium hubs. In the rear of
the RS and USA Cup, the stabilizer bar is also adjustable. Spacers are added to
the control mount (outer suspension bushing) to eliminate rear wheel toe in on
trailing throttle during cornering, the so called: “Weissach Axle? effect. The
rear control arm adjustment plates are modified and are different left and
right. They can also be flipped side to side, which allows more negative camber
for racing applications. The upper shock mount is changed to a ball joint
design, similar to that used in the front. Overall ride height is approximately
40 mm lower than a European Carrera 2 and 50 mm (~2?) lower than a USA Carrera
2. Alignment is set with one degree more negative camber front and rear. The
Carrera RS Touring and Basic have genuine magnesium wheels that are 17? diameter
and 7.5? and 9? wide front and rear respectively. These four magnesium wheels
save a total of 10.6 kg (23.3 pounds) of weight, compared to aluminium wheels.
The RS America and Carrera Cup USA both are equipped with the 7×17 (front) and
8×17 (rear) aluminium wheels that are optional on the standard Carrera 2.

The standard Carrera 2 and right-hand drive Carrera RS
models are the only cars with power steering; all other Carrera RS and RS
America cars have manual steering.

Engine Comparison

Table 3


 


92/93
Carrera 2

 


93 RS
America

 


92 RS
Carrera Touring M002

 


92
Carrera RS Basic, M001, M003 and Carrera Cup USA

 

Engine Type

 

M64/01

 

M64/01

 

M64/03

 

M64/03

 


Selected Pistons / Cylinders

 

No

 

No

 

Yes

 

Yes

 


Power
steering Pump Drive

 

Yes

 

No

 

Optional

 

No

 


Flywheel

 

Dual Mass

 

Dual Mass

 

Dual Mass

 

Sports

 

Fan/Alt.
Drive

 

2 Belts

 

2 Belts

 

1 Belt

 

1 Belt

 


Flattened Suction


Oil
Line*

 

No

 

No

 

Yes

 

Yes

 



Engine
Mounts

 

Hydraulic

 

Hydraulic

 

Solid Rubber

 

Solid Rubber

 



DME
Control

 

Standard

 

Standard

 

Sports

 

Sports

 


Displacement

 

3600 cc

 

3600 cc

 

3600 cc

 

3600 cc

 


Compression Ratio

 

11.3:1

 

11.3:1

 

11.3:1

 

11.3:1

 

Horsepower

 

 

250 DIN/247
SAE Net @ 6100 RPM

 

250 DIN/247
SAE Net @ 6100 RPM

 

260 DIN/256
SAE Net @ 6100 RPM

 

260 DIN/256
SAE Net @ 6100 RPM

 


Torque

 

 

310 NM @ 4800 RPM

 

 

310 NM @ 4800 RPM

 

 

325 NM @ 4800 RPM

 

 

325 NM @ 4800 RPM

 



Fuel
Octane Requirement




*For
tire clearance in right rear

 

90 Octane

 

 

 

 

 

90 Octane

 

 

 

 

 

93 Octane

 

 

 

 

 

93 Octane

 

 

 

 

 

Table 3 compares the engines of the three
cars.

The RS America and the Carrera 2 share basically the
identical engine but the RS America engine deletes the power steering pump
drive.

The engine in the Carrera RS and the Carrera Cup USA is a
“blueprinted” version of the Carrera 2 engine. Pistons and cylinders are
selected to optimize power output and minimize variation in output between
engines. A sports flywheel, seven kilograms (15.4 lbs.) lighter than the Dual
Mass unit is fitted. The drive belt system is simplified from two belts to one
belt and the fan belt monitor is eliminated, the alternator light now serving
this purpose. Engine mounts of the Carrera RS and Cup USA are changed to a solid
rubber design. The suction oil line from the oil tank to the engine is flattened
to improve rear tire clearance. The power steering pump drive is eliminated as
on the RS America. The Carrera RS and Cup USA have a remapped DME chip that has
more aggressive timing advance characteristics and thus produces ten more
horsepower. Because of this the RS requires a Research Octane Number (RON) +
Motor Octane Number (MON) /2 fuel of:  98+88/2 =93 octane gas. The standard
Carrera engine requires a 95+85/2=90 octane fuel.

The 29 Carrera Cup USA engines that were dynamometer tested
at Andial/PMNA did not vary more than 1.5 horsepower from 275 SAE in race trim
with no mufflers and a modified air cleaner on 92-octane gas. Porsche reported
on delivery to Andial/PMNA that seven of the Carrera Cup engines had cam timing
within spec, but settings not identical to the other 38 cars; these seven
engines were corrected at Andial/PMNA. Andial/PMNA preformed no other engine
modifications other than sealing them to make tampering impossible.

Gearbox and Shift Lever Comparison

Table 4


92/93
Carrera 2 & RS America

 


92
Carrera RS All Versions & Carrera Cup USA

 

Gearbox Type

 

G50/05

 

G50/10

 


 

 

 


Gear
Ratios

 

 

 

 

 


 


1sg1st
Gear

 

3.500

 

3.154

 


 


2nd
Gear

 

2.059

 

1.695

 


 


3rd
Gear

 

1.407

 

1.407

 


 


4th
Gear

 

1.086

 

1.086

 


 


5th
Gear

 

0.868

 

0.868

 


 

 

 

 

 


Ring &
Pinion Ratio


 

3.333

 

 

 

3.444

 

 

 


Limited Slip Diff.

 

 

 

Optional (M220) 40% fixed
lock

 

Standard 20-100% Variable
lock

 




Trans.
mount

 

 

 

 

 

 

Standard

 

 

 

 

Harder Rubber

 


Synchronizers

 

 

 

 

 

Standard

 

 

Steel, Modified for Quick
Shifts

 

Shift

Shift Lever Ratio

 

 

 

4.0:1

 

 

3.4:1

 

 

Shift Lever Travel

 

 

 

± 62 mm

 

 

± 52 mm

 

 



Lever
Cockpit

Position

 

 

 

Standard

 

 

10 mm to Left, 28 mm
Taller

 

 

Table 4 shows that the G50/05 gearbox of
the Carrera 2 and RS America are identical and a 40% disc type limited slip
differential was optional.

The G50/10 gearbox of the Carrera RS and Carrera Cup USA
has a standard limited slip differential of the variable 20/100 percent type as
on the Turbo. This limited slip provides a 20 percent locking factor on
acceleration, but “locks up” to a 100 percent factor on trailing throttle to
minimize drop throttle over-steer. The gear ratios of the G50/10 have been made
closer by changing both first and second gear of the turbo. The ring and pinion
are slightly higher numerically (i.e. lower).

The synchronizers of the G50/10 gearbox are made of steel
and modified for quicker shifting for gears one through four and the
transmission mount is made of firmer rubber.

The shift lever on the Carrera RS and Cup USA is modified
to shorten the throws and move the lever closer to the driver.

Brake Comparison

Table 5

 

 


92/93
Carrera 2 & RS America

 


92
Carrera RS All Versions & Carrera Cup USA

 

Booster Type

 


 

Vacuum

 

Hydraulic

 


Ratio

 

3:1

 

3.6:1

 


 


 

 

 

 

 


Master
Cylinder Diameter

 


 

20.64 mm

 

25.4 mm

 

Proportioning Valve Switch Pressure

 


 

45 bar

 

55 bar

 


 


 

 

 

 

 


Front
Brakes

 


 

 

 

 

 


 

Calliper Body

 

C2/C4 Size

 

Turbo Size

 


 


Piston
Diameter

 

40+36 mm

 

44 + 36 mm

 


 


Disc
Type

 

Ventilated

 

Ventilated & Cross
Drilled

 


 


Disc
Diameter

 

298 mm

 

322 mm

 


 


Disc
Thickness

 

28 mm

 

32 mm

 


 


 

 

 

 

 


Rear
Brakes

 


 

 

 

 

 


 

Calliper Body

 

C2/C4/Turbo Size

 

C2/C4/Turbo Size

 


 


Piston
Diameter

 

30+28 mm

 

30+34 mm

 


 


Disc
Type

 

Ventilated

 

Ventilated & Cross
Drilled

 


 


Disc
Diameter

 

299 mm

 

299 mm

 


 


Disc
Thickness

 

24 mm

 

24 mm

 

Table 5 shows that
the Carrera 2 and RS America share the identical vacuum boosted braking system.

The Carrera RS variants and Carrera
Cup USA have a completely different braking system than the Carrera 2. On these
cars, the larger diameter, thicker, cross-drilled front disc and larger calliper
of the 964 Turbo are used. In the rear the calliper and disc designed for early
Carrera 2 based Carrera Cup cars is used. This calliper body is the same size as
the C2/Turbo rear calliper and has four pistons of the same size as the Turbo
but it is made to accommodate the thinner, cross-drilled Carrera Cup disc (Turbo
discs are 28 mm thick).

The RS/Carrera Cup USA boost system
is of the hydraulic type as used in the Turbo and Carrera 4 but with a reduced
booster factor of 3.6 versus 4.8:1 on Turbo. This, coupled with a larger 25.4 mm
master cylinder versus 23.18 mm on Turbo, gives the Carrera RS and Carrera Cup
USA cars a very firm pedal feel.

 

Optional Equipment For Road Versions

Table 6


92/93
Carrera 2

 


93 RS

America

 


92
Carrera RSTouring

 


92
Carrera


RS
Basic

 


92
Carrera Cup USA

 


17″
Wheels

 

Optional

 

Standard

 

Standard

 

Standard

 

Standard

 


Sport
(M030) Suspension

 

Optional

 

Standard

 

N/A

 

N/A

 

N/A

 

Limited Slip Dif.

 

Optional

 

Optional

 

Standard

 

Standard

 

Standard

 


Power
Steering

 

Standard

 

N/A

 

Optional*

 

N/A*

 

N/A

 



Model
Designation Delete

 

Optional

 

N/A

 

Optional

 

Optional

 

Standard

 



Sun
Roof

 

Optional

 

Optional

 

Optional

 

N/A

 

N/A

 


Air
Conditioning

 

Standard**

 

Optional

 

Optional

 

N/A

 

N/A

 


Tinted
Windshield

 

Standard

 

Standard

 

Optional

 

Optional

 

Standard

 



Heated
Seats

 

Optional

 

N/A

 

Optional

 

N/A

 

N/A

 

Headlight Cleaners

 

Optional

 

N/A

 

Optional

 

N/A

 

N/A

 



Radio

 

Standard

 

Optional

 

Optional

 

N/A

 

N/A

 


Bumper
Shocks

 

Standard**

 

Standard

 

Optional

 

N/A

 

Standard

 



Sport
Seat

 

Optional

 

Standard

 

Standard

 

Optional

 

N/A

 

Steering Hub Ext.

 

N/A

 

N/A

 

Optional

 

N/A

 

N/A

 



Roll
Bar

 

 

N/A

 

 

N/A

 

 

N/A

 

 

Z option with M003

 

 

N/A

 

*Power steering standard on all RHD cars.** Standard USA only

The Carrera Cup Vehicle M001

The M001 Carrera Cup racing car is not certified for
road use and included all the M003 Competition modifications listed above plus
the following

The USA Carrera Cup Edition cars had
all the M003 and M001 modifications performed by Andial/PMNA to become Carrera
Cup racing cars, excepting as noted below.

  1. Stiffer springs and shock absorbers
    with a different monoball mounting front and rear.
  2. Longer 66mm rear wheel studs with
    21mm rear spacers for 68 mm offset wheels (not used in 1993 season).
  3. Aluminium 9.5? X 17?, 68mm offset
    wheels in rear. (9.5? X 18? 47 mm offset, 3 piece wheels for the 1993 season
    cars).
  4. Aluminium 8? X 17?, 52mm offset
    wheels in front (same as RS America and Carrera Cup USA rear wheel, changed to
    8X18, 3 piece wheels for 1993 season)
  5. Further lowering to just clear a
    100mm block and changing of alignment to -2°30′ negative camber front and
    -2°20′ negative camber rear and corner weighting. The unique RS rear
    adjustment plates are flipped left to right to achieve this setting.
  6. Steel lug nuts
  7. Size 235/45 front tires
  8. Installation of ABS defeat switch
    on dash as well as an ABS high pressure defeat switch on the master cylinder,
    this modification allows the driver to turn off the ABS manually at the
    dashboard or with very high brake pedal pressure. The American Cup cars
    required a special wiring harness to do this since the wiring harness in these
    cars is the standard American harness. Carrera Cup cars in Europe use the
    connections in the European RS harness that are already provided.
  9. Removal of brake backing plates and
    installation of protecting shields and boots to protect ABS wiring from heat
  10. Removal of the brake-proportioning
    valve.
  11. Pagid racing brake pads without
    wear sensors
  12. ABS brain moved to the alternate
    mount above original to protect it in a crash.
  13. Straight pipes replace mufflers
    (catalytic converter remains).
  14. Modification of air cleaner to
    eliminate silencing and improve airflow.
  15. Removal of engine mounted heater
    blower and replacement with bypass pipe.
  16. Dynamometer test of engine.
  17. Clutch plate replaced with racing
    style plate.
  18. Matter Roll Cage installed (a ?Z?
    option in Europe for M003 cars).
  19. Removal of fog lights and
    replacement with red painted aluminium plates (not required on European car
    which uses the RS false fog lights).
  20. Removal of both airbags and lower
    dash padding (not required on European car).
  21. Removal of alarm and central
    locking system (not required on European car).
  22. Towing hooks installed front and
    rear.
  23. Removal of the front bumper alloy
    beam and hydraulic mounts.
  24. Removal of clutch helper spring at
    clutch pedal.
  25. Camber brace installed across front
    struts.
  26. Driver?s side window safety net
    installed.
  27. Clear Vinyl helicopter tape
    covering of headlights.
  28. Wooden drivers floorboard, removal
    of rubber floor padding.
  29. Removal of oil cooler fan,
    installation of duct plate to guide air to cooler.
  30. MOMO steering wheel with horn and
    turn signal contacts removed (USA cars only).
  31. Hood pins installed (USA cars
    only).
  32. Stiffer rubber front stabilizer
    bushings installed.
  33. Stiffer rubber steering couplings
    installed.
  34. Exterior activation of the kill
    switch with a cowl mounted knob.
  35. A Recaro SPG bucket seat covered in
    cloth for driver only.
  36. Solid magnesium engine mounts and a
    stiffer rubber transmission mount (European Cars only).
  37. Spherical bearing drop links for
    rear stabilizer bar (European Cars only).
  38. Rear trailing arm adjustment plates
    swapped side to side for more negative camber.
  39. Removal of engine belly pan.

The M001 Carrera Cup cars do not have
any ?Carrera RS? labels on them.

The Carrera Cup racing cars weighed approximately 2520
to 2540 pounds.