924Board.org

[gohim]

Having driven a number of examples of both cars, I would say that unmodified, the 924S will take the 931.

The 931 is slow off the line, where the 924S has a very flat torque curve with close to full torque available from the bottom rpm to the top. That means that while it accellerates well, as someone else has already pointed out, it will not feel like it's fast.

The 931 having a non-linear accelleration curve will feel fast, BUT, be way behind initially. By the time it catches the 924S, a 1/4 mile will be over.

My friend's 81 931 shed it's first turbo at under 6K miles (leaking oil seals), replaced under warranty by Porsche even though it was outside of the 2-year factory warranty. The car only has 13K miles on it now, and has always been garaged, but unfortunately, it looks like it is going to be ready for another turbo (leaking oil seals again) when it comes out of hiberation for the first time in over 15 years. My friend treats his 931 with kid gloves, as he bought it new from Rusnak Porsche in Pasadena, CA in 1981.

All that being said, the 931 has never impressed me (slow initial accelleration, and tricky throttle pedal work needed for maximum accelleration), nor have many of the 924S and 944 that I have driven (strong but flat torque curve, and not enough engine sound).

Still, I made my choice. I have a nice, really nice 87 924S.

[Eturbo924]

If you go strictly by the factory numbers the 931 is slower. Rated at some thing like 9.3 to sixty. 924S is rated at 8.0 to 8.5 depending on year.

So I still say we need a showdown to settle this!

1987 924S against 1980 931 and then 1988 924S against 1981-82 931!

Who will step up with a car to throw into the mix?

Would make a great story for Pano or Excellence.
_________________
1982 924
1992 968
2003 C4S
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[Maybe924]

Not sure where you're getting the 9.3 number as a factory figure. There was one test in 1980 by road & track that produced a 9.3 0-60 and any 931 owner will tell you this number is suspect and if you look at the other 5 tests performed you'll see they are all between 6.9 and 7.7secs to sixty. The ROW car getting the 6.9 and low 7s with the US cars seeing 7.5 and 7.7 to 60. That 9.3 number is just plain wrong, and has no basis in reality as an indicator of a 931s 0-60 performance. It rather arbitrary actually.

I posted this before but here it is again. If you look at the chart on the 9.3 0-60 time you'll see the other numbers are also WAY off. The car either had mechanical problems or the testers were serious morons. The factory never specified 9.3 as the 924 turbo's 0-60 time, US spec or otherwise.

http://www.weissach.net/924-944-968_RoadTestSummary.html

Also Gohim, not sure why it'd take a 931 a 1/4 mile to "catch up" with a 924S... though it starts off slower, the 931 will still beat the 924S to 60mph.

Course, a lot of this discussion is pointless since for around $200 you can modify a US Spec 931 to ROW boost levels and then its not even close.
_________________
1981 931 GT (CGT Intercooled)
1985 911 Targa Carrera (Sold)

[Squeaky]

Well if I get a Turbo it will be a series 2, and I will run track days so the power at higher RPMs shouldn't be a problem.

With a series 2 how much could I play with the boost? Can I bump it up 2 or 3 PSI or are we talking like 5-7 or what? How much power would that give me?

Would I need to but a boost controller?

[Eturbo924]

Yeah it was the 1980 test of the 924 (S) specification turbo with the larger wheels and sport suspension that I am quoting. As I recall the article did state that the factory quoted 9.3 sec to 60. But as you and I have discussed I to do not put much faith in those numbers. Both 931s that I have driven (while not in perfect tune) felt much stronger than that number would indicate.

The ROW cars were definately much faster than the stock 931s here in the USA... but as you indicate... $200 remedy to that!

Still it begs the head to head comparison.

Come on I still have not goated anyone into this hu?

I think for pure thrill the 931 would be hard to beat. Both 931s I drove were the series 1 cars. The turbo came on with a wallop around 3500 rpm. It was a rush. Can not say they were dead before that either.

It was fun fun fun!
_________________
1982 924
1992 968
2003 C4S
Parts Parts Parts and More parts.
E-mail me for parts you need!
Drive Fast!

[ideola]

[Maybe924]

Eric,
That 9.3 second 0-60 number is definitely the one to quote if you want to goad a 931 owner into a drag race thats for sure.

Squeaky,
You can safely (I say this assuming the car is in good mechanical shape) turn the boost up to 10psi on 93 octane without fear of detonation. Any more and you're outside of what the factory felt was feasible for this engine without an intercooler. I suppose with the lower compression in the US cars one could run 11psi without problems but when you push it, expect problems to crop up more often. Some say you can run higher boost without problems but considering the cost of replacing holed pistons I'd err on the side of caution.

With an intercooler I run 12psi of boost, but instead of detonation, now the limiting factors are fuel delivery and the ability of my turbo to blow any more air. I think the Series 2 stock turbo would likely run outta steam above 14psi.
_________________
1981 931 GT (CGT Intercooled)
1985 911 Targa Carrera (Sold)

[gohim]

Why can't we just agree that the 931 and 924S are pretty well matched, as the hp reported for both is very similar? Yes, you can modifiy the 931 to increase boost, and that should bring the 931 closer to Euro Spec for the 931. But what about comparing a Euro Spec 924S?

But here's another observation for you. I looked up the 931 and 924S performance specs in one of the road test reprint books (specifically PORSCHE 924 Gold Portfolio, published by Brooklands Books).

According to several British Magazine road tests, the 931 was uniformly reported good for 7.7 secs to 60mph. I found four British Magazine road tests for the 924S with specs listing (7.4 secs, (2) X 7.5 secs, and 7.8 secs).

This would indicate to me that in Euro Spec Trim, the 924S is in fact faster 0-60mph than a Euro Spec Trim 931. Of course these results are so close that the driver probably had more influence than the test gear.

If I remember correctly the Euro Spec 924S was initially rated 170hp in 1986. In 1988 when Porsche went to it's Worldwide Same Horsepower Policy, the US 924S got a bump up to 160hp, and the Euro 924S took a hit, going down to 160hp.

The Euro Spec 931 was always rated at 170hp, wasn't it?

So that makes both cars real Euro Spec HP the same at 170hp. Which is the reason that road tests place them pretty even.

[9xx]

My experiences about the P-cars I have owned:

Fastest first:

1. 924 Turbo stock 177hp
2. 944 S stock 190hp with a dyno sheet showing 189hp. I eventually installed a ProMax chip, possibly 195 hp after that. Manufacturer claimed 20hp gain but I do not believe in that.
3. 944 8-valve US spec 143hp. Sold in California when new, then to Israel, from there to Scandinavia.
_________________
Mikko

All gone: 931 '82 Alpine White, original option "220" G31 with LSD + 3 x 944

[Maybe924]

Info from the 924 Bible (Porsche 924 Brian Long)

ROW Porsche 931 Series 1 Turbo 170hp, Max Torque 180lbft
Factory 0-60 time: 7.8 seconds
AutoCar records 0-60 time of: 6.9 seconds

US Spec Series 1 Turbo 143hp, Max Torque 147lbft
Road & Track records 0-60 time of 7.7 seconds

ROW 931 Series 2 Turbo 177hp, Max Torque 188lbft
No reported performance figures

US Spec Series 2 Turbo 154hp, Max Torque 155lbft
No reported performance figures

ROW 86-87 924S 150hp, Max Torque 144lbft
Factory quoted 0-60 time: 8.5 seconds
Motor records 0-60 time of 7.8 seconds

US 86-87 924S 147hp, Max Torque 140lbft
An unnamed test confirms 0-60 time of 7.8 seconds
Car & Driver manages 0-60 of 7.5 seconds

ROW 88 924S 160hp, Max Torque 155lbft
No performance figures reported

US 88 924S 158hp, Max Torque 155lbft
No reported performance figures
_________________
1981 931 GT (CGT Intercooled)
1985 911 Targa Carrera (Sold)

[Eturbo924]

Love that book
_________________
1982 924
1992 968
2003 C4S
Parts Parts Parts and More parts.
E-mail me for parts you need!
Drive Fast!

[J1NX3D]

[emoore924]

First car? You need something reliable and cheap. Neither the 924S nor the turbo is that, comparably. Then n/a is much tamer and less complex, but you're still talking about a 25 YEAR OLD CAR.

I own a turbo and an n/a. I've owned an 88 24S (great car BTW). I have driven all three hard so I know what they'll do.

At this stage in their lives, even the best examples tend to be cantankerous enthusiast cars, whose parts you can't get at pep boys anymore, where the a/c doesn't work or is non existent, the electricals can have more gremlins than a 1940's Warner Brothers cartoon, and your local shop won't or doesn't know how to work on them (and I appreciate your enthusiasum regarding self-applied labor but without some serious knowledge, especially regarding the turbo, you can get yourself into some serious trouble...)

If I had to rank them in order of "most appropriate for a first time owner" to "least appropriate...", I would say:

924S, 88
924S, 86 or 87
924 n/a, 1980 or later, with 5-lug wheels
931 (that's a turbo) 81 or 82.

Any model not mentioned shouldn't be considered. Please note, I own a 79 n/a and an 80 turbo, and they're not on the list, so I'd say I speak from first-hand experience.

All of this list falls behind pretty much any modern car from any decent manufacturer like toyota or honda. They're just better technology, more reliable, easier to find parts for, and so on. The a/c might even work and if you get something after 1993, you're even likely to find a car with air bags for the driver and passenger and ABS -- a significant +! for a new driver, ask your parents (sorry, I had to throw that in ) Go look in consumer reports or carsense.com to find what you want.

The old cars are fun, but they're fun because they're challenging and interesting to own and tinker with. That's NOT what you want with a first car. And not what you would want for a daily driver.

YMMV
IMHO
blah blah,,,
etc...

[Squeaky]

Challenging and interesting is what I want...

I'm not bragging but I'm at the top of my Tech High School Automotive class.
I KNOW that I have ZERO experience on these cars, but the thing is I will have help of three instructors that all have 20-30 years experience (one of them with sports cars and some exotics as well) and I can bring my car to school and work on it so I think I would be ok there.

As far as reliability I am hearing mixed things. Some people say they aren't reliable and I should buy a Honda, and others say if you keep up with it and dp preventative maintenance it will serve you well. Which one is correct???

As far as needing a car that is cheap, I am not worried about the actually cost of the car or insurance at all (I already got a quote and everything). I am only concerned about parts and maintenance costs.

[J1NX3D]

even though you're buying it to work on, with whichever type you go with i would still buy the best condition car you can afford, both mechanically and cosmetically (maybe more just cosmetically since you are so keen to work on it) while still budgeting for parts.

this is where preventative maintenance by past owners is so important, because it will save you a lot of tears in the long run. best cond car = preventative maint by p.o.= reliable and a good project car for you.

neglected, these cars can be a 'mare.
_________________
'86 944