What's the difference: 911 to 930

[steviee7]

I'm just really interested in what the difference is in the engine, I have an 86 911 and I know that a 930 of that year is basically turbocharged but what else as far as the motor? Are they both 3.2l DO they have a different compression ratio, different piston, crankshaft, etc...?
The reason for my concern is that I wondered about aftermarket supercharging or turbo kits. and will any form of charging be very bad for my "non-charged" engine, heads/pistons/ etc... (provided my a/f mixture is set up within safe limits.)

As you can see in my signature I own a VW Corrado G60 which as you may or may not know is supercharged. Right now my charger is out of my VW and I've just been toying with the idea of being able to fit it into my 86 911. Since I never drive them at the same time I figured would it not be cool to have the best of both worlds?

[jrdavid68]

Hi steviee7,

Aren't those vintage Turbos 3.3L ? Here's a link I found:

85 911 turbo vs stock 3.2

[steviee7]

Very nice link, ( I feel stupid now that I could have done that search) but thanks anyways...

I see that there is a big difference here. I wonder what turbo kits come with, If I need to do too much work I might as well scrub the idea. Has anyone done an aftermarket kit out there in Porsche-land??


By the way has anyone seen a kit for sale? and from whom.

[jeff1hughes]

The 930 is a 3.3, and uses different compression ratio for sure. As far as internal components I don't know off the top of my head but The Performance Handbook will have all the answers.

[MAS]

Aside from the engine sizes, I think you'll find there there are quite a lot of internal differences.


-MAS

[WydRyd]

The Carrera motor has the same bottom-end as the 930 motor.

The 930's Pistons (7.0:1 Compression ratio) and Cylinder (97mm) are different to the Carrera's Pistons (9.5:1 C/R) and Cylidner (95mm).

The 930 also has different heads with smaller exhaust ports (1-1/2" as opposed to 1-5/8"). The 930 also has the CIS Injection, whereas the Carrera runs the Motronic EFI.

The 930 also has a different/larger oil pump to that of the Carrera.

As for your question about turbocharging the Carrera, a few of us on this board have done it and if you are interested in further details, send me a PM

On a stock US spec motor, 0.5bar non-intercooled and 0.7bar intercooled without touching the internals. Any higher boost and you have to start decompressing the engine