Wideband Results

[cmaxcliff]

Innovate looks good. I have an older Fast meter but I am thinking about buying something new. Has anybody tried the Fast wireless unit linked below? Is there another better unit?


https://www.summitracing.com/parts/fst-170301

[davisshannon]

Thanks, I’ll try that.

[94touring]

I did it a little different at idle. I have 500, 750, 850, and 1300 rpms. Ignore map set to below 1300. 500 @5° 750 @10° 850 and 1300 @15°. I idle at 950 rpms when warm.

[davisshannon]

Something like this?

[davisshannon]

Thanks, I’ll drop to 0 at 85kpa. And you’re saying start at 15 from 500rpm and continue to 1500rpm before ramping up?

[94touring]

Your MAP curve starts too soon. It should be more like 0 at your 85 kp instead of 5. You mentioned you're at 450 meters elevation, which is 96 kpa. Sea level is 100kpa (101.3 to be exact). Since 0 is 100kpa and 5 is 85kpa on your MAP curve and you drive at a 96kpa elevation, WOT no vacuum throttle condition you will be adding 0.33 degrees of timing to your whole curve. Drive somewhere that's 900 meters higher and you're at 85kpa and adding 5 degrees across your curve at all times. This is one reason why I have different timing files for different elevations. If I ran my sea level file at 8k feet, I'd be severely over advanced. I try to have vacuum advance start to take place somewhere around a 75% throttle position and be at the maximum vacuum advance around a 25% position. This is guessing because I don't have a TPS to tell me actual throttle position, and there's fudge factor for minor elevation changes, but you get the idea. My sea level file is good to 2000 feet. Then there's a 2000-4000 and a 4000-8000 file. All tuned on an actual drive across the country and tuned/tweaked to suit.

Also try a higher idle advance. 10 is low. It probably will like 15+

[davisshannon]

Got my 123 installed today. Used the two lower vacuum ports on each carb, into a T, and then both of those into a T to the 123 ignition.

And here’s the curves we set up as a starting point that seemed to run well.

I’ll have to start learning a bit more about how the ignition works and gradually get things tuned better, but I am happy with how it drove compared to my previous Magnaspark.

[cmaxcliff]

[94touring]

[74 Thing]

[cmaxcliff]

[94touring]

Did you happen to have the tune feature selected when you saw 20°? Meaning you manually bumped it up via tune while it was running. Might explain why you mentioned detonation, in what area of your map I consider to be set a bit low for advance. Maybe toss a timing light on it and verify your 10° at idle with and without vacuum hooked up.

[cmaxcliff]

Well that's embarrassing. I don't have an explanation but I do know that my idle timing showed 20* on the phone app screen. Perhaps I was experimenting when I took the screenshots? I have no explanation. The 20* was the key to having the idle absolutely stable and constant from a cold start to a hot engine. 10* was not enough to deliver that result.

[94touring]

Cmax- I'm looking at 10° at idle for you also. You have ignore MAP below 1500.

Alstrup and I posted at the same time.

[Alstrup]

If your distributor is set the way the above screen shots tell, you have no vacum advance at idle. In fact you set it to ignore the vacum signal below 1500. Sooo.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[davisshannon]

I’ll be getting my 123 installed next week. We are taking vacuum off of the carbs as my manifolds aren’t tapped.

Any initial advice on 123 setup? Any traps to avoid?

[cmaxcliff]

[Alstrup]

[cmaxcliff]

I have followed this thread for years and I am impressed with what John Connelly has posted about Weber jetting. However I have no interest in being ultra lean at cruise. I understand the desire but not having a choke I don't want to live with poor drivability during warmup. On the other hand my modern computer controlled cars are wonderful. I do like reading about what you guys are up to though.

Going back in time some manufacturers did understand the advantages of vacuum advance such as GM and British brands which used it on their high performance street cars. Where things were wrong were performance engines with a barrel for each cylinder. I have worked on a number of different brands with independent runners and I can't remember any with vacuum advance. I may be wrong. Those cars seemed to follow the race car norm but racing does not benefit from load based timing changes because they are always under heavy load at WOT. The super sports street engines should have been fitted with vacuum advance and they would have run much better.

Fitting and tuning the 123 Tune BT to my modified 356 engine made a very dramatic improvement in temperature, idle stability, throttle response, and fuel mileage. Every street engine will benefit from some sort of load based timing variation.

These were my settings for 32,000 miles @ 29-30mpg, flawless cold start idling and drivability, quick response tip-in, with IDF44/36 carbs. The numbers are useless to others but do show the difference between idle, cruise and WOT which are very different from a stock 356 manual advance only distributor of 6* idle and 36* WOT. My car ran 20* at idle, 39* at cruise, and 29* at WOT.

[Zed999]

The lean cruise with vacuum advanced timing is nothing new though is it? Its a standard feature of our old VWs from new 50+ years ago or am I missing something here?