ericablack36

Hi

Excuse this basic question and apologies if it has been answered before.

I have read somewhere that the manual 1993 964 was improved in a number of ways in comparision to 964s from ealier years. I would appreciate it if someone could tell me what were those improvements/changes.

cheers

springer3

There were running changes, but the 964 changed very little. Some of the limited-production models were produced only in the later years. I am sure this is not complete, but here is what I know:

There was no C2 in 1989, only the C4 which was going to be the last 911 before the 928 became the new flagship for Porsche.

The problematic dual-mass flywheel appeared in 1990. In 1991 the spoiler lost its manual switch in the rear of the car, and one of the two control modules disappeared.

The cylinder head seals were improved during 1991. Also, the rear shock top mounts changed.

In 1992 the flag mirrors were changed to aero-look, and the Design 90 wheels were changed to Cup 1.

The RSA was produced only in 1993 and 1994.

I am not aware of any differences among the 1992, 1993, and 1994 models.

Almost all 964s had the flywheel replaced. Any that leaked at the head seals had that fixed under warranty. Aero mirrors and Cup 1 wheels are popular upgrades on the early models.

swftiii

Adding: rear brake calipers increased in size in 1992, but are an easy upgrade for early cars.

andrew911

I think the clutch was improved to a better unit sometime during 1992 model year, so to be safe all 93-94 had the updated clutch.

Also, my '93 has the current 134 freon for A/C...I'm not sure if 1992 had that yet (a big difference if you care about A/C, as the old R12 is no longer available and it's not cheap to convert to 134)

velocitylover

Adding: 1989 C4 had no air bags, using cup 1 wheel required a spacer in tie rod end to avoid rubbing in full lock up (later years were cup 1 ready), dizzy belt upgrade was standard since '90-91?,air intake bacame plastic in '91-92?

R6XTERRA

Also, the earlier cars 89,90,91 have the cast intake manifold vs the 92,93,94 have the plastic version. Correct me if i am wrong.

jimq

My 91 has plastic

anto1150

92+ models have oval gear lever bushes, so you can easely upgrade to RS short-shifter.

springer3

MY92 was all R-12. R-134a conversion is no problem - lots of cars including early 964s have been converted using standard adaptors. Conversion is less expensive than a repair and re-fill using R-12.

andrew911

Actually this is incorrect- there was no vent tube on my 93. It's an easy enough upgrade to do (changing the distributor, or as the europeans say "dizzy", belt is a little more involved but not the end of the world).

gchristofi

I vaguely remember a v. small change to the rear light cluster, somewhere around 91-92. Aimed at reducing condensation.

hamah

Specific to the 93 over 92:

Synthetic oil
Revised Air Bags
LUK double mass flywheel installed (standard on the C2)
C4 had Valeo friction disks on the differential locks
revised tension ring for front axle (new p/n)
AC refrigerant changed to R-134a, other changes include refrigerant oil and receiver dryer changes
rear heater blower resister changed (new p/n)
new wheel alignment data in US
distributor sealing ring changed
regulator mounted in alternator changed (new p/n)
C2, C2TL, Turbo 3.6 have new covers on inside of front wheel carrier
Turbo has revised crankshaft pulley
oil cooler thermostat insert revised (new p/n)
oil cooler design revised (new p/n)
Turbo has upgraded O2 sensor control unit
Turbo engine control system revised

elbeee964

...and faster paint.

boxsey911

I believe that by 93 Porsche finally got the 964 right out of the box. Those of us with earlier ones had to get the little annoyances with the design fixed ourselves.

andrew911

Is this correct? I'm almost sure my car doesn't have anything referring to synthetic either in the engine compartment or manual- I thought the factory synthetic fills for 911s started with 993? At least for non-turbo cars- I have no idea what turbo cars had....

I've been running 20W-50 non-synthetic for 20 years in my 93 and prior 78 and 87...changed every 12 months which works out to about 2,000-3,000 miles the way I use the car (weekend good weather spring/summer/fall only). I don't think there would be any benefit to synthetic given my usage- the oil looks like new when changing, but had the factory recommeneded synthetic I would have been using it on my 964.

On a side note, the original poster seems to be new to rennlist and was probably expecting a couple of responses like tire size differences or something and here we are all bragging about our expanded knowledge about these cars....to outsiders we probably seem like people who play super high level video games seem to me, or people who are into the nuances of star treck episodes or something Hey, everyone has to have something they are obsessive about and for us it's cars (or here 964s specifically) -ha!