924Board.org

[Guest]

From: michael jos barnes
Email: michaeljosbarnes@aol.com
Date: 02 Mar 2000
Time: 18:13:19

is the 924 body the same as the 931 body and what about the transmission? does the 931 have more power? or is the 931 the 924 with a turbo
whats the deal ?
thanks alot ,
mike

[Guest]

From: Fredrik
Email: i97lafr@itek.chalmers.se
Date: 02 Mar 2000
Time: 18:34:48

Hello,

You are correct, the 931 is basically a 924 with a turbo. Needless to say, there are of course some other differences between the two cars (clutch, brakes, wheels etc). The transmissions also differ. As far as I know the 931 has a different gearshift pattern than most 924:s (1st gear down to the left) and it also has higher gearing. The bodies are practically the same, although the 931 has the characteristic air ducts on the front center plate between the headlights. When it comes to power, a late Euro 931 produces 177 hp whereas a 924 produces a mere 125.

Hope this helps
Fredrik Larsson
'82 924

[Guest]

From:
Email:
Date: 03 Mar 2000
Time: 01:27:58

I think the spark plugs on the 931 are easier to get to then on the 924, pretty sure. And the 931 has a hood duct also. I drove a 85 944 and wasnt to impressed over my 77 924, there basically the same car but 944 has a 2.5L engine(wow). If I ever get another Porsche its gonna be a newer 928 with the 5.4L V-8 yeah baby yeah!

[Guest]

From: Brad Wright
Email: wrightbr@kos.net
Date: 03 Mar 2000
Time: 10:12:16

If you went for a test drive and couldn't notice the difference between a
77 924 and a 944 , Did you take the car above 2 grand? 944's have
some speed ( more horsepower ) to go along with the 924 handling
ability, and how about the 5-speed in the 944 a lot nicer than the 77
924 4-speed!!! The cars are basically the same, but as the they get
newer the factory just kept refining it ( more speed,better brakes, nicer
interior, etc. ) Therefore the later cars are much better cars. Don't get
me wrong I love my 924, but more for it's classic appeal, and elagant
shape ( no boy racer fat fenders ) I would rather drive my 944 every
day ( more fun!! ) than my 924. Brad

[Guest]

From: Bob
Email:
Date: 03 Mar 2000
Time: 10:30:12

A 931 is a 924 Turbo, probably the most economical porsche with the greatest performance and performance upgradability of all the cars built in the late 70s to mid 80s. The 924 was the platform which brought Porsche back from the brink of bankruptcy during the oil crunch of the early 70's. The 931 first proposed in 78 was built for the euro market in 79, with a few US spec cars brought to the US in that year. Porsche having learned alot from its turbo race cars, put the technology to work in the first water cooled turbo by Porsche. At the same time the factory was planning a series of race cars to promote the 924. The Carerra GT GTS and GTR were built in different stages and configurations from 80 to 81. The GTS was the factory prototype for the soon to be 944 Turbo. The story goes that one of the 924 GT Lemans cars in 80 was equipped with the Protoype 944 engine. After the development of the 928 motor, Porsche took the technology and engineering and built the 944 2.5 liter engine from the ground up, some writers state that porsche split the 928 motor and came up with the 944 motor, hogwash, I 've seen no facts to that.

More than likely due to the dewindling demand for 924/924T in the US and the extra effort in making the 924 Turbo, Porsche pressed on with getting the 944 to the european market in 82 and the US market in 83. There are a few 81 944s built by the way. The 944 engine in itself is an interesting design and a seperate story.

The 924 itself continued production until 88 in Europe, I'm not sure when the crossover to the 2.5 liter engine occured, maybe our euro counterparts can have an answer o that question. For the US market porsche offered the 87 and 88 924S with and downrated 2.5 liter engine. The 924 body style has a better drag coeffcient and thus a higher top speed than the 944, that is the reason for the detuned 924S motor (keeping things fair).

Back to the 931, the european 931 stayed the same specs throughout production til it ended in 83. The 83 models allegedly went to Italy only. I have yet to see one advertised or an actual photo of one. The US market 80 model has a lower compression and a Porsche designed transmission (aka snail shell G31), this was the same trans used in the GT unit with a few internal parts uprgraded for the extra GT HP. The 80 also had a hyrid half vacum half digital timing sytem. In 81 and 82 the 931 went to the same trans found in 944s built up to 85.5 . The engine recieved a compression bump and full digital timing, a few more options here and there.

The debate over brakes on the 931 is ongoing. The 79 931 were equipped with 924 brakes, disc in the front and drums in the back. The brakes were a little under powered when taking the car into performance driving, and besides there was a push from owners and enthusiaists to have four wheel discs. The 80 cars at least for most of the US market I feel were equipped with full disc brakes. It may be a regional thing but I haven't seen any drum equipped 80 931s. There was an option which delivered the cars with full disc, sport suspension and 16 inch wheels, all the 80's I have seen have had this option. If you find a drum brake 80 931 don't worry, the 944 brakes bolt on with a little work. The 81 and 82 931 came equpped with full disc, the same system used on 944s.

There are so many common parts used from the 76 924 to the end of the early 944, that you can be surprised what can be swapped and upgraded.

The 931 itself can be modified for extra HP. Without going into those mods, I just point out the progression from one model to the other.
US 931 154 HP
euro 931 177 HP
GT 210 HP
GTS 245HP
GTR 280-345+ God and Ferry Porsche only know

The blocks stay the same all the way through
The crank is the same til the GTR
The pistons change on every model due to that is were the compression ratio is primarily set.
The rods stay I believe stay the same til the gtr
The head is the same til the gtr, there may be be some valve size differences on the GTS

The gtr and gts start getting wild on the intake system. The GT adds an intercooler and the GTS adds a 944 style intercooler in the nose and a 928 fuel distributor. The GTR has a kugelfisher mechanical fuel injection pump , ram induction intercooled intake and a dry sump oil system.

The turbos on these cars vary and I can't remember the specifics, other than there were like six different numbers for the stock us and euro 931. And it finally got settled down to two numbers, a euro version and a us version, both interchangable. They spool up at different rpms.

I'm going from memory on this so the facts may be a little different and if anyone knows something for sure, please correct me. Time for me to get back to work.

[Guest]

From: Brad Wright
Email: wrightbr@kos.net
Date: 03 Mar 2000
Time: 10:55:14

Just thought I would give you the Canadian stats on the 924S, we got
the car back in 1986 with the 2.5L motor, for 86 and 87 it had the down
rated motor but for 88 we got the 160HP motor in the 924S. Brad

[Guest]

From: Vaughan
Email: vscott39@hotmail.com
Date: 03 Mar 2000
Time: 13:18:59

Whoa, I think Bob gets the Pulitzer for that essay!

Nice work!

Vaughan

[Guest]

From: Webmeister
Email: webmeister@924.org
Date: 08 Mar 2000
Time: 09:12:26

Yep. In fact, I think I'll plagarize the whole thing soon as I get a chance.

But, first, drivers ed this weekend. Cars first, website second. Sorry. (Well, no I'm not sorry so there!)

John

[Guest]

From: Bob
Email:
Date: 09 Mar 2000
Time: 12:41:07

Got a tip that the GTS head has larger ports. This is from a GTS club sport owner.