924Board.org

ks114 · Joined: 23 Nov 2016 Posts: 13 Location: Kansas

Hi, This is my 2nd post here. Hope you can help. I just bought a 1981 924 with a Weber conversion. The problem is the vacuum advance isn't hooked up.
What port on the carb does it hook to? I Ve got pics of the carbs/manifolds if it helps. Thanks,Steve

Fifty50Plus · Posted: Sat Nov 26, 2016 7:06 am Post subject:

Vacuum advance goes below the throttle plate.
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

ks114 · Joined: 23 Nov 2016 Posts: 13 Location: Kansas

Is there a port there that I can put a fitting in?

The craig · Joined: 13 Nov 2015 Posts: 8 Location: Brisbane Australia

There are a few different thougts on this some people take directly off the manifold others go for ported and multiple carbs make it more fun
I would go of the ported vac on the carbs and tee both ports together and to the dizzy
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ks114 · Joined: 23 Nov 2016 Posts: 13 Location: Kansas

Are the fittings for the vacuum ports readily available at the parts store, or is this a Weber specific part?

MikeJinCO · Posted: Sun Nov 27, 2016 12:21 am Post subject:

I have a completely different setup because I'm at 8000', but the Redline folks had me plug/cap and not use the vacuum advance, go to a zero bypass on the accelerator pump jet(I think that is the right term) and set the ignition advance to about 15 degrees BTDC. At least 5 degrees of that is for altitude.
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Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

muffin787 · Joined: 13 May 2015 Posts: 5 Location: Puerto Rico

I convert my 1980 924 to webber many years ago. I don't use the vacum advance. if you have two side draft, you will notice a pulse vacum. It make very difficult or impossible to set the advance. You will only have to work with the mechanical(centrifugal) advance.
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Porsche 924 1980, 944 brakes, GM alternator, GM Master Cylinder, 40decoe weber, Crane ignition module.

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11723 Location: PacNW

Path of least resistance is to have your distributor recurved for straight mechanical advance. There are many specialists who can readily do this.

Next choice is Ignition 123.
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WeiBe (1987 924S 2.5t) - 931 S3

RC · Joined: 25 Mar 2007 Posts: 2636 Location: Australia

There appears to be a lot of confusion and misunderstanding on the subject of vacuum advance on many forums, including this one. A few minutes googling and reading the theory is a good start, irrespective of whether it is on a 924, Ford, Chevy or whatever, its all the same. The same theory applies equally to modern EFI & ECUs, albeit oriented towards emissions control in preference to performance.

Here`s a few links that should be sufficient but google will find millions more. Opinions vary immensely but the basic facts & theory remain constant.

https://en.wikipedia.org/wiki/Ignition_timing

http://www.gofastforless.com/ignition/advance.htm

http://server1.chevytalk.com/~tony/fusionbb/showtopic.php?tid/58447/

https://www.cartechbooks.com/techtips/fordignition/
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