Handy930

What emission equipment differences were there between California cars and the rest of the States in 1979? Where air pumps, advance timing on start, Cats all the same? Any other differences?

pu911rsr

No CATS on 79 49 state or Cali 930's, don't know the differences.

Phil

WPOZZZ

My Last 50 930 was from Cali and IIRC, the sticker in the door jamb said Non-Catalyst.

Handy930

My 79 had the cast headers connecting to the heat exchangers and was told that the headers replaced the old style Cats that were attached directly to the heads. The only other thing I observe is the distributor has the advance timing on cold start. My manual shows the CA cars with the dual vacuum/pressure lines.

pu911rsr

Not cats but thermal reactors - all US 79's came with them - most people removed them as they were very hard on exhaust valves and replaced with ROW headers.

Phil

Handy930

What is the functional difference between a catalectic converter and thermal reactor?

Porsche 930

Quick answer;

Cat Converters work with heat, oxygen, and catalysts (usually precious metals like palladium, rhodium, platinum) to break down exhaust pollutants.

Thermal Reactor is like a super heated chamber to burn exhaust pollutants.

Archaic early Cats were restrictive to exhaust gasses and robbed motors of power.

Handy930

Thanks for the quick answer. I would guess it would be hard to find a 930 that still has the TR's installed with all the options available. Did the later models with Cats eliminate the air pumps and all the related devices and plumbing?

Porsche 930

The air pump may have been replaced but the electronic and mechanical emissions pieces that replaced them were not better in eliminating future problems. From what I understand the Cats that were introduced world wide in '86 were quite restrictive. Remember, auto manufacturers were still struggling with how to meet the EPA regs during the '80's.

I have the original Thermal Reactors for my 930 in a box (where they belong!) and have what many referred to as headers in their place. This allows all other original exhaust pieces from the heater boxes onward to remain in place. Most scrutineers overlook the lack of TR's as they realize the problems they can cause.

Porsche 930

There are separate versions of the North American 1979 930 Emissions Stickers for the California and 49 State vehicles. These Emissions Stickers are found on all NA '79 930's on the underside of rear deck lid (silver versions also exist). The most obvious difference between the two is additional equipment and tubing seen on the Vacuum Hose Routing Diagram of the CA sticker. Other differences between the '79 CA 930/63 and 49 State 930/64 engines can be found in the Porsche Workshop Manuals.

The first picture is the CA version (930.006.537.06), second is the 49 State version (930.006.537.05).

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Handy930

Thanks for the information. Now the next step is to try to understand what all the components were designed to do as far as emissions are concerned. I will reference my factory manual.