924Board.org

[stv951]

Hello all,

I am interested in lightening my 80s 924.
Will be 5 lug with 931/early 944 arms and brakes. What shoud I expect weight-wise as a reasonable target ?
Anyone who has a light car please pop in. Whats your weight and how did you achieve it ?

[9XX Girl!]

[Rich H]

Ali rear arms would help, I think Bass GT has one of the lightest, IIRC just under a ton.
_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[stv951]

so, only just 1000 kg for a car that weights 1080 in stock form ?
Sound dissapointing

[ideola]

There's tons of info here on weight reduction, most of it is cross-referenced in the stickied Performance Upgrade thread at the top of this section. You should start there.

I don't think 1080 kg is a correct figure. The 931 official curb weight was something like 2500 pounds, give or take a few, which is over 1100 kg. Double check your figures on that one.

Most of the results I've seen indicate that net weight can be reduced somewhere between 200-400 pounds, depending on how radical you go, how much steel you replace with fiberglass or carbon fiber, how much glass you replace with lexan etc. I believe you should be able to achieve right around 1000 kg, but probably not much more.
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erstwhile owner of just about every 924 variant ever made

[stv951]

[gegge]

Close to 1000 kg shouldn´t be a problem. But sub 1000 is getting expensive and very time consuming. A 931 can reach 895kg road-leagal and full roll-cage with some effort and the lightest 924 I´ve read about is 70kg down.
_________________
Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs

[stv951]

[gegge]

http://utzon.se/gamla/My931/My931.html

He was ridiculus fast in that car, embarrassing modern and tuned 911´s. A shame that the video link doesn´t work any more.

EDIT: I DOES WORK

Stock engine and stock brakes
_________________
Carl Fredrik Torkildsen

924 turbo -81 Carrera GT RESTOMOD
924 turbo -80 Dolomite De Luxe
924 -85 DP kit, BBS RS, M030 and tuned engine
924s -86 Black on black turbo with Fuchs

[stv951]

[JayZzzz4]

When I bought my 924S, it was a track car. Only thing in it was the two front seats, motors for the windows and the window visors. Hard to say how fast it is because I haven't been in a 924 before, but I do notice night and day if I have a passenger with me. Feels very light and accelerates fast, even if 5th gear. It's easy to spin your wheel at a stoplight without reeving it up, I haven't tried too much because it's hard on everything, but mostly around turns one wheel will spin if you acc. too much. It shirps into 2nd and I did it once into 3rd. The first time driving it in the rain, I ended up sliding sideways through a roundabout. I think a bunch of people thought I was crazy
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White 1987 Porsche 924S manual

[emoore924]

Spec book says 2623lbs. I've always had trouble making that weight even with the roll cage.

I think you can get to 2400lbs pretty quick by essentially removing the interior, dash and all the sound deadening material. After that, you'll need lots of lexan, carbon fiber, fiberglass and ingenuity.

Oh, and a period article on the 924DP cars listed them as being 2138lbs.

[simsport]

I have my sprint car at 980 kilos wet. That still took some work. You can get down to around 900-950 kilos but its not always going to help your speed as much as you think.

Its a well establsihed fact that a 924 can lose more weight from the back than the front hence you may drop your weight but end up slower due to lousy traction.

Dont underestimate the effects of poor traction off the line and out of the tight/slow corners. I have been beaten by a tenth after a sprint over 1.5 miles on a super fast circuit when I was actually quicker everywhere other than the first 60feet!

cheers
simon
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Blown is always best!

[RC]

Has the OP actually weighed his car to get a baseline? Forget what the book says it SHOULD be.

The later 924`s got progressively heavier with the extra "features" fitted. My 77 NA street car with manual windows, no sunroof, no emissions, no bitumen sound deadening, no BS, and no spare & jack came in at one metric ton exactly, 1000Kg (whats that = 2200 Lbs?) on a weighbridge with 10 Kg tolerance. Oh no CIS and no stock cast exhaust manifold either.

Now with a supercharger & mounts, pulleys, FMIC, plumbing, amp, more speakers and a bit of fuel it weighs 1050 Kg. Less than 1000Kg should be easily obtainable on a track car even allowing for the roll cage IMHO.

Simsport gives good advice on the rear weight. Even on a street car (with a hoon driving) the difference is very noticeable between carrying a spare with a full tank and not. This is the biggest advantage of the 911 of course. Suspect there is more advantage to relocating the battery to the rear than a polycarbonate (Lexan) hatch, although I haven`t personally done so, yet.

[ideola]