What settings will give the desired dwell control like this:

At and below 100kPa 2.5ms.

From 100kPa to 300kPa ramp up to 5ms,than limit it at 5ms.More than that usually destroys the coils we use.


We recommend base dwell=2.7 msec and dwellmap=8

The maximum dwelltime extension in function of MAP is *1.4 (+40%). 3.8 msec in your case with 2.7 msec base dwell. That is 1.4*1.4 = 1.96, so 'almost twice the power.

In short: *2 time (that is *4 power) is not possible to configure, and very dangerous anyway.

We had ECU (powerdown related) crashes at high power (lots of fuel in cylinder unless you reboot very quickly). These happened at about 4.5msec dwell in audi 3B factory harness (although non-stock ign for cyl 2-5). The crash just went away when we lowered dwell.

The total maximum extension is appr *1.86 if VBATT is also down. Mostly interesting during cranking. Hopefully your VBATT is above 12V during high power runs.

The car in question is not a 3B but ABY, the coils are non standard and are LS2 and run optimally at 5 msec

Are you saying the ECU cannot do it? I've seen a BMW car running 3.26 which ramps to 4.8 with no issue,1018.0.html

What is the "scaling" of the variable called Ign adjust Cold 0deg C (Ignition Settings dialog) ?

2009-11-27 VemsTune was not yet compatible with 1.1.63 firmware realtime lambda value.

2009-12-04 VemsTune is better,reading well in the middle of the lambda range