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  View original topic: Stock Distributor Advance Curve Diagrams
EverettB Tue Jan 20, 2015 4:56 pm

With thanks to mikedjames for posting these in the Gallery
[Edit: dupes removed]










































airschooled Tue Jan 20, 2015 6:43 pm

:shock:

So beautiful! Thank you!

:D

Tcash Sun Feb 15, 2015 11:35 am


Tcash Sun Feb 15, 2015 11:36 am


Multi69s Sun Feb 15, 2015 2:31 pm

Sticky ? :D

tasb Sun Feb 15, 2015 8:39 pm

X2

Although I have to ad that some of those diagram labels do not ad up to a recognizable distributor - at least not for VW.

67 Sunroof Sun Feb 15, 2015 10:41 pm

I'll be the first to ask.....awesome but what do they mean?
Which is right for me? How can I tell?

Juanito84 Mon Feb 16, 2015 10:30 am

'67 Sunroof wrote: I'll be the first to ask.....awesome but what do they mean?
Which is right for me? How can I tell?

What do they mean?

These graphs show the acceptable advance curves for VW distributors. So if you have one of the distributors listed on any one of these graphs then all you have to do is check your advance curve(s) and see if your distributor is still within spec.

Some graphs only have one curve on them, measured against vacuum (mm HG) with no RPM listed. These are vacuum only distributors like the ones used on 1970 and older manual transmission VWs. There are some with two advance curves, one marked "a" (vacuum curve) and the other marked "b" (centrifugal curve). These are SVDA style distributors. The ones with three curves (one of them bends down) are DVDA style distributors.

Note that the degrees are distributor drive degrees. To get crankshaft degrees you will need to multiply the number of degrees by two.

Generally, this is just to make sure your distributor is within spec, not for chosing a distributor. Normally you would chose the distributor based off the number on the carb. But I suppose you could put it on a dyno and find a distributor with a curve that matches your engine even better.

67 Sunroof Mon Feb 16, 2015 5:38 pm

Thanks man! I have several of the above distributors. I have no idea which to use with my stock 1600dp with baby dells (34b) carbs.
I've been told the svda would be best (205) but have only dvda distributors. If I leave the retard advance disconnected I assume it would only affect the third curve?
Thanks again :D

Juanito84 Mon Feb 16, 2015 7:47 pm

'67 Sunroof wrote: Thanks man! I have several of the above distributors. I have no idea which to use with my stock 1600dp with baby dells (34b) carbs.
I've been told the svda would be best (205) but have only dvda distributors. If I leave the retard advance disconnected I assume it would only affect the third curve?
Thanks again :D

Correct. Just leave the vacuum retard disconected.

As far as the curve, I'd try the most agressively advancing curve.

modok Mon Feb 16, 2015 7:52 pm

Nice to see this info all in one place! Thanks.

now, I guess I need to get a better computer. it nearly locks up trying to load all those images :lol:

furgo Mon Jan 15, 2018 8:51 am

This is a fantastic post, but every time I've tried to find the info for a particular distributor I've spent quite a lot of time actually finding the post in the first place. Once you've found it, you then need to look at all curves to find the right distributor, as the part numbers are only on the images, which preclude a quick text search.

As I found myself doing this for the nth time today, I went ahead and added the VW part number code to each image, so that the distributor curve can now quickly be found by hitting Ctrl+F on the browser and searching for it. This should also make this post appear on the forum/Google search when giving a distributor part number as search query.

While I was doing this, I noticed there were quite a few image duplicates, which I removed. If you look at the post source you can see which images were actually removed, as their file names are all in sequence and the missing ones can easily be spotted.

To the mods: if you find this useful, please feel free to update the original post with the extra info (or replace the contents), and then remove my post to avoid duplication.

Here it goes:

EverettB wrote: With thanks to mikedjames for posting these in the Gallery

Legend


111 905 205 T vacuum control curve
113 905 205 K vacuum control curve
113 905 205 L vacuum control curve
315 905 205 vacuum control curve
315 905 205 B vacuum control curve

311 905 205 T vacuum and centrifugal control curve

311 905 205 S vacuum and centrifugal control curve

131 905 205 G vacuum control curve
311 905 205 Q vacuum control curve

311 905 205 P vacuum and centrifugal control curve

311 905 205 M vacuum and centrifugal control curve

311 905 205 L vacuum and centrifugal control curve

311 905 205 AK vacuum and centrifugal control curve

311 905 205 AJ vacuum and centrifugal control curve

311 905 205 AH vacuum and centrifugal control curve

311 905 205 AG vacuum and centrifugal control curve

311 905 205 AF vacuum and centrifugal control curve

311 905 205 AE vacuum and centrifugal control curve

311 905 205 AD vacuum and centrifugal control curve

311 905 205 AC vacuum and centrifugal control curve

311 905 205 AB vacuum and centrifugal control curve

311 905 205 AA vacuum and centrifugal control curve

113 905 205 AL vacuum and centrifugal control curve
211 905 205 S vacuum and centrifugal control curve

211 905 205 Q vacuum and centrifugal control curve

211 905 205 N vacuum control curve
211 905 205 P vacuum control curve

181 905 205 centrifugal control curve

113 905 205 AN vacuum and centrifugal control curve

113 905 205 AM vacuum and centrifugal control curve

022 905 205 P vacuum and centrifugal control curve
022 905 205 Q vacuum and centrifugal control curve

022 905 205 H vacuum and centrifugal control curve

022 905 205 E vacuum and centrifugal control curve

022 905 205 D vacuum and centrifugal control curve

022 905 205 A vacuum and centrifugal control curve

021 905 205 L vacuum and centrifugal control curve

021 905 205 K vacuum and centrifugal control curve

021 905 205 J vacuum and centrifugal control curve

021 905 205 H vacuum and centrifugal control curve

021 905 205 G vacuum and centrifugal control curve

021 905 205 F vacuum and centrifugal control curve

021 905 205 E vacuum and centrifugal control curve

021 905 205 C vacuum and centrifugal control curve

021 905 205 B vacuum and centrifugal control curve

021 905 205 A vacuum and centrifugal control curve

021 905 205 vacuum and centrifugal control curve

furgo Mon Jan 15, 2018 9:59 am

One of the reasons I was looking for this post today was because I found a piece of information that relates to my distributor, for which there don't seem to be any curves available (although the data itself is on Bentley).

There is a M107 technical note on the late Michael Knappmann's site that, once translated from German, reads:

Quote:
5 - Ignition system

a - Distributor
4/1800 022 905 205 S
4/1800 021 905 205 P

[...]

The advance values for both distributors correspond to distributor 021 905 205 G (see Repair Manual section M 3.2/1-3 and M 3.3/5-20).


A while ago I plotted the distributor curve for 022 905 205 S / 021 905 205 P (which are essentially the same part, the only difference being that ..205 P has a RPM-limiting rotor):



Comparing it to the curve of the 021 905 205 G distributor, and bearing in mind that on the diagram below the RPM and advance values need to be multiplied by 2 (they refer to distributor rpm and degrees, vs. crankshaft rpm and degrees on the above):



The curves look similar enough. Comparing the actual data from Bentley and the Repair manual, there seem to be just slight differences of 0.5 advance degrees.

nos64notch Wed Feb 15, 2023 5:38 am

Anyone know where I can find a curve for VW 311-905-205D?

tzepesh Thu Oct 19, 2023 1:19 am

Does anybody have the advance curves for 043905205L and 022905205S?

Wildthings Tue Dec 19, 2023 12:19 am

tzepesh wrote: Does anybody have the advance curves for 043905205L and 022905205S?

The curve for the 022-905-205s has been shown in several places in the above posts.



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