Installing 123 Ignition Distributor - advice sought

[KTPhil]

I graphed the few that I am considering for my '71 Fastback (1776cc)

The yellow and orange are '71/'70 stock curves from the Bentley.

Right now I used the recommended "F" (purple) but is it "too little, too late" and the car is sluggish.

Next I will go as aggressive as "E" (green) but it may be a bit much and I don't want to risk detonation, so I'll watch it.

If it's too much, I may try "B" (blue) which has a little less max advance, and is slightly slower to rise than stock.

The vac advance will add another 9 degrees, though they are not strictly additive, depending on load as well as rpm.

The "123" tables above and the "123" curves I made are engine degrees advance at engine rpm, just as you usually measure it.

NOTE: This graph (and the data posted above and by 123) is not comparable directly to the Bentley curves. Bentley measures distributor advance degrees (not crankshaft degrees) at a given distributor rpm (not engine rpm). Here is an overlay I made years ago from Bentley (ignore the orange dotted line).

[KTPhil]

I decided to aim high and selected curve "E".
A brief run around town, on the freeway, and up a long full throttle hill so far, and no sign of pinging.

She pulls much better in the midrange, as you would expect!

I'll be on the lookout for any pinging at the higher final advance this setting allows, even a few degrees higher than stock. I am running premium. I'll keep testing to see if the pinging comes back when she gets hot from long hot drives on the freeway over the next few weeks, but this is a good sign.

[KTPhil]

I am getting an occasional miss/hiccup, more often when cold, but I am guessing this is mixture causing it, not advance. My guess is that it is running rich, partly based on the 24 mpg reading over the 200 mile trip for Meet in the Middle, mostly freeway, where it should have been in the high 20s.

After another valve adjustment, I'll hook up my AF meter/bunged resonator, and have a go at recalibrating the MPS on the road. Last time I did this was before the latest rebuild.

So the final tuning of both advance and mixture will determine which curve is really best for power, economy, and cool running. Everyone likes Cool Runnings.

[heimlich]

If you can't find a good one ask if you can exchange your unit for the programmable one. Then you can enter into the unit the curve you want.
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[KTPhil]

Is this the Bluetooth model? I saw some reports about interference on those models, but can't locate it at the moment. But thanks for the tip, always nice to have backup plans.

[heimlich]

I asked if he had a unit that is programmable. His reply was 123/TUNE+-4-R-V-V.

It does show wireless on the page for it.
_________________
www.vwnos.com [email protected]
Classic Brands. Classic Quality.
Not all parts are made the same. NOS OE/OEM parts made mainly in West Germany, Early Germany, and Early Brazil are where VW produced the best quality parts and best fitting products.
5% Off your order with coupon code: 5%OFF
Restored Distributors Available (<--Click here)

[Jason37]

Anyone running the tune + version? If so what temps are you seeing on the dashboard?

[NotchVuu]

[Tram]

Here you go:

The numbers you can see at the bottom are RPM
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[NotchVuu]

[Tram]

Oops, sorry, I just noticed you are in Australia. Your engine is different than USA which got fuel injection. Your Aus distributor may have had a different curve entirely- I don't know.

If I were you I would try out the 010 and 019 curves here and see which best suits:

Link in case the image stops working
http://www.sparkingplugs.com/resources/_wsb_500x354_Advance_019-010-009.jpg

These were the "hot" VW distributors. The 009 is sort of a dog because it was originally for industrial engines.
The nice thing with this 123 is that you can play with the advance points moving things around till both you and the engine are happy. As we've found out, what works really well on one Porsche engine does not on another identical engine.

You can just bypass the vacuum altogether. My experience with the Tune Plus models has been that it seems every other one does not like the vacuum. It could also be me being an idiot though. On the base 123s where you just select a pre determined curve rather than programming it the vacuum works fine.
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[HenrikL]

If I read the manual correctly, a 1968 manual transmission carburator engine would have used one of the three distributors:
311 905 205 F
311 905 205 G
311 905 205 Q

They seem to be vaccuum only and have the same curve.

[HenrikL]

[NotchVuu]

[heimlich]

[NotchVuu]

[NotchVuu]