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Sveina · Joined: 02 Nov 2002 Posts: 92 Location: Norway/Sweden

Can anyone tell me some specs on 931, and I think about original max torque and HP DIN and what RPM they are on. And I wonder if it was differences in the engines codes (XK, XJ, XE ...)? I read it was 154 HP in US-model, and 170 first year in RoW, next years 177. Is this correct? No idea about the torque. So at least someone with turbo can tell me their specs? Would be nice to know!
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Sveina
Porsche 924 1976 RoW NA
Porsche 944 1982 RoW RSR
Porsche 951 1987 RoW 400 hp+
Porsche 951 1987 RoW 230 hp daily driver
Dodge Viper GTS 2001 soon supercharged
MB E320 CDI 4matic 2007
x 4 Porsches and lots of cars from different brands

Paul · Posted: Sat Apr 05, 2003 11:56 pm Post subject:

Here's the 1980 931:

924 turbo · Posted: Sun Apr 06, 2003 5:16 am Post subject:

1980 931, US spec:
150 HP @ 5500 rpm (DIN)
206 NM @ 3500 rpm (DIN)
Top speed 132 mph (212 kph)
0-100 kph 9.4 seconds (at DIN curb weight + 1/2 payload)
1/4 mile 16.3 seconds
Standling kilometer 30.0 seconds

1981 931, US spec:
156 HP @ 5750 rpm (DIN)
210 NM @ 3500 RPM (DIN)
Top speed 134 mph (215 kph)
0-100 kph 9.3 seconds (at DIN curb weight + 1/2 payload)
1/4 mile 16.2 seconds
Standing kilometer 29.8 seconds

1981 931, RoW spec:
177 HP @ 5500 rpm (DIN)
250 NM @ 3500 RPM (DIN)
Top speed 143 mph (230 kph)
0-100 kph 7.7 seconds (at DIN curb weight + 1/2 payload)
1/4 mile not available
Standing kilometer 27.9 seconds

Sorry, I don't have the specs for the '79 or '80 RoW 931, but they are 170 DIN HP. All these numbers were from the factory service manual and the '81 model supplement.
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Jon Furst

mrgtturbo · Joined: 06 Jan 2003 Posts: 526 Location: Skowhegan, ME

I've got that same issue.
I don't know about anyone else but can't read the print on the scan... too small. I'll write out how they compare in my next message. However one thing to keep in mind, the 81 and the 82 turbos were differant. I don't know if the N/As were aswell or not. This is a Mag from 79'.
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81' 931

mrgtturbo · Joined: 06 Jan 2003 Posts: 526 Location: Skowhegan, ME

I see someone allready replied with some figures.
The Mag didn't compare them anyway, ooopps.
But it did give a Torque spec of 147 ft lbs @ 3000 RPM.
I don't know if thats the 79' or 80' model, (or if the 81's and 82's where nearly the same), as I said the Mag is a 79'.
Then ofcourse there were upgrade packages, and special orders available, which could make a differance aswell.
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81' 931

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

1979 931, Euro-spec (Source=owners manual)
7.5:1 compression ratio
170 HP @ 5500 rpm
245 NM @ 3500 rpm
Top speed 225 km/hr ~=140mph
0-100 kph 7.8 sec
1/4 mile not given - hey, it's a German language document...
Standing kilometer 28 seconds

Once upon a time someone was asking about gear ratios, so while I'm at it, I'll post them since this year car seems to be an "oddity". I don't really know what the numbers in parenthesis are. (Porsche, not Audi snailshell)

1st ( 12/38 ) ~= 3.166:1
2nd ( 18/32 ) ~= 1.777:1
3rd ( 23/28 ) ~= 1.217:1
4th ( 29/27 ) ~= 0.931:1
5th ( 34/24 ) ~= 0.706:1
Reverse ( 22/48 - 12/16 ) ~= 2.909:1
Differential ratio ( 8/33 ) ~= 4.125:1

Does anyone "in the know" know how these figures stack up against the later cars? Same, better, worse, inconsequential difference??
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'79 Eurospec 931

924 turbo · Posted: Sun Apr 06, 2003 11:42 pm Post subject:

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

Sorta figured the numbers in parenthesis were gear teeth numbers, now it's confirmed... The "how things stack up" question was directed at the gear ratios, as opposed to HP and performance ratings. I've never really dealved into the pros and cons of having one set of ratios over another, but I realize that to some folks certain setups are more desireable than others. Surely certain ratios are designed to provide better low-end torque or a broader power band, whereas others are for better fuel economy, and that there are trade-offs no matter what the numbers are.

I was just curious as to whether this early production model had a setup that was different than others, and what might it's advantage might be (if any). I'm guessing that the difference between US and European model HP output had something to do with emission standards or fuel economy, so did perhaps the gearbox differ as well for similar reasons?

Can any of the hardcore machine heads out there offer some insight into all this?
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'79 Eurospec 931