924Board.org

epsylon · Posted: Fri Jun 20, 2003 1:55 am Post subject: ehxuast manifold differences

how can you tell the difference between an early model turbo exhaust mainifold and a late model ( 81-82 ) exhaust manifold?
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'82 931
'78 928
Howell Henderson
South Padre Island

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

I believe the later design has extra "webbing" on the underside as reinforcements. I've never seen an early and a late one side-by-side for comparison. Also, see http://www.924.org/techsection/931_turbo.htm for some other info about the manifold design and changes.
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'79 Eurospec 931

924 turbo · Posted: Fri Jun 20, 2003 4:28 am Post subject:

The part number is cast quite noticeably onto the manifolds, so it's pretty easy to go by the part numbers.

'79-'80: 931 111 093 02
'81-'82: 931 111 096 00
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Jon Furst

Lizard · Posted: Fri Jun 20, 2003 4:33 am Post subject:

why are the turbos not interchangeable between 80 and 81/82? I know the compressors are smaller, but what else
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3 928s,

924 turbo · Posted: Fri Jun 20, 2003 4:38 am Post subject:

By "not interchangeable" Porsche just means that they are different sizes and not direct swaps. The earliest of the 924 turbos had no sealing rings for the turbo gaskets, then they added one for the turbo-manifold connection, then eventually another at the turbo-exhaust pipe connection. The last versions of the '80 have both sealing rings, but are "larger" turbos than the '81-'82 versions.

Many '81-'82 931's I've seen, including my own car, had late '80 (dual sealing ring) turbos installed in place of the original "smaller" turbochargers.

My current turbo on the '81 is a European-spec late 1980 version.
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Jon Furst

CMXXXI · Joined: 05 Nov 2002 Posts: 1939 Location: Vicksburg, MS

My '79 Euro model has the "recent" housings/flanges as well. Shortly before I bought it, the PO had the unit replaced, and the unit installed by the dealership was of the newer type. Don't know if they "automatically" upgraded it, if the "old style" was no longer available or what. None the less, it is the true European setup. Here's the info from the data plate:

Grosse K26-2470R6.10
ATL NR 82 057 0125
AUSF NR 5326 970 7007

I understand that the line titled "Grosse" (German for 'large' or 'size') is the code that denotes the compressor & scroll housing configuration. The data line beginning in "AUSF NR" is the KKK part number. FWIW, the part number on the dealership invoice is 931.123.002.FX, and I don't know what the number on the middle line is for.
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'79 Eurospec 931

924 turbo · Posted: Fri Jun 20, 2003 1:57 pm Post subject:

Those numbers match my turbo exactly, CMXXXI.
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Jon Furst