Hi All -
Being that Porsche sold cars in all 50 states, shouldnt there be a factory listing for the different carb settings/jet sizes for the 911? Obviously the cars that were sent to different altitudes had to be set up with different jetting. Has anyone ever heard or seen any sort of technical bulletin?


Scott S

Check in Anderson's book, he discusses the origional factory jetting (smog) and the recommended jets.

I have a copy you can borrow Scott.

Does this work?

The top line of the chart (2.0 liter with L cams) looks quite right, though I don't have the spec book handy.

I know that the original venturis are the 27mm ones, a common upgrade was to enlarge to the 30mm ones on the 40 IDA carbs (along with larger jets).

I don't believe that Porsche specified different jet specifications for higher altitudes, though I'm sure most owners living there had to change their jets to compensate for the lower oxygen levels.

Scott,

want to borrow an innovate?

ha....
Told you my little 2.0 jetting wouldn't work for you
were using:
34vents
170mains
another 50 units of 2ndary enrichment (IDS)
and about 220airs
55idles

I just bought 35vents and 180/190 mains for the new 2.1 that is getting built.

Ha! Holy cow Brant!

Brant, who do you order your jets from?

Thanks for the chart Jmill.

Mr Gint - I would love to borrow that book. I think I will also call PMO, as I will be using their spacers between the head and the intake manifold - I am sure that will alter things too.

Happy New Year

PMO has jets and many other parts.