I’ve followed the past postings on the 123Ignition and was able to get mine (Bluetooth Version) installed in my 914 with a Raby 2270 engine. My question is I’ve never messed with the Map Curve Settings, I’m still getting some misfires when the car is cold until it warms up. I’m not sure if I need to adjust the Map settings to address this problem or help on reaching peak performance? Thanks for any suggestions. I’ve attached a couple of current pics of the settings for the Centrifugal Curve and Map Curve. Thanks

Centrifugal Curve Pic

I'm on a Raby 2316 with 9560 cam & SDS fuel & ignition with ITB's so horrible MAP signal, gave up on using MAP and went with TPS only.
The SDS uses an excel spreadsheet format to compute fueling and spark advance based on temperature, TPS value and RPM. Very simple.
I'm advancing spark faster than your centrifugal curve shows--I'll try to paste from the excel column below:
RPM IGN
500 10
750 10
1000 14
1250 14
1500 15
1750 17
2000 21
2250 24
2500 27
2750 30
3000 30
3250 30
3500 30
3750 30
4000 30
4250 30
4500 30
4750 30
5000 30
5250 30
5500 30
5750 30
6000 30
6250 29
6500 29
6750 28
Wow, it worked....the IGN values are degrees BTDC just the same as your centrifugal advance values..(I have fuel cut at 6750 as a rev limiter with this system).
IF you're on a single Throttle body you can probably be ok with MAP signal but if it's ITB's you'll get stumble at part throttle due to the choppy signal...

Nope I have dual Weber 44s

OK, now I think I understand the 123 system which uses the MAP to simulate vacuum advance so your advance curve and mine are more similar during normal acceleration progression as it adds up the rpm dependent advance to the MAP driven advance....

When you say misfires when cold, do you mean a “sneeze” out of the carbs when cold. If so, it’s fairly normal when cold. Do you have a wide band O2 sensor installed?

You could pull a vac line from all four and "tee" them together for a more-reliable MAP signal. Alternatively, I've seen them interconnected to a common small vac canistor from which the signal is sourced.

No 02 sensors installed on this Type 4 engine. As far as the misfire its more of a cough. I’m not sure that you even need a Map Curve setting when your using carbs instead of Fuel Injection.

I went ahead and set the Map Curve numbers to Zero. I cain’t see where they’re affecting anything when it comes to the run ability of this engine. There are no vacuum hoses on this Weber carbs (44s) setup except for the one vacuum outlet on the 123dizzy which isn’t hooked to anything. Thanks for your help. It appears the missing I’m hearing mostly through the d/s carb when cold is normal, it disappears once the temperature gets up on the engine.

12/29/19 I sent a message to 123Ignitionusa,LLC inquiring there suggestion on using the Map Curve on my application. Ed Madok responded on Sunday with the following comment: Ed Madak
To
r b
Dec 29 at 4:39 PM
Hi Roy
It is ok to set the map at 0. In actuality if you had not changed it the outcome would have been the same.Because there is no vacuum to cause the map to come live.
As for the misfire. It should be ok if it leaves after warm up. However I think I might look at the coil or even fuel mix as the culprit. Have you conferred with the engine builder?
Hope this helps
Ed


Thanks Ed for your help, Happy New Year.

You really need a wideband O2 to tune the car. Otherwise you are just guessing.