MoTeC Global Forum

hi guys. So I've notice my rev limiter doesn't "bounce" like a normal limiter, it seems to just hold itself at that rpm instead. Im trying to figure out how to get my limiter to bounce with some ignition cut. I know there's engine speed limit A and B but it doesn't seem to matter if they're set the same or different. Can somebody lead me in the right direction please? Also what should the ignition range and fuel margin be set to? Thanks in advance.

Hi,

Is there a reason that you want the limiter to add harshness into the engine?

If you want the Engine Speed Limiting to be harse, then reduce your Engine Speed Limit Ignition Range to 0, this will give you 100% Ignition Cut as soon as the Engine Speed hits the Engine Speed Limit that has been set, If you also want to have Fuel Cut Limiting, then set the Engine Speed Limit Fuel Margin and Engine Speed Limit Fuel Range to 0 as well.

What the Range and Margin to is adjust the type and harshness of the Engine Speed Limiing function. If you have the following setup;

Engine Speed Limit set to 7000rpm
Engine Speed Limit Ignition Range 200rpm
Engine Speed Limit Fuel Margin 100rpm
Engine Speed Limit Fuel Range 200rpm

Then what will happen when the engine speed exceeds 7000rpm is that the M1 will start to ramp in the amount of ignition cut applied over a 200rpm range, so if the engine speed gets to 7100rpm, then there will be 50% ignition cut being applied at that engine speed. It will also start to introduce fuel cutting from 7100rpm as the Engine Speed Limit Fuel Margin has been exceeded, and will also ramp this in over a range of 200rpm. If the engine still gets to 7200rpm, the M1 will be applying 100% Ignition Cut and 50% Fuel Cut.

Sorry for bringing back this old post.

What does a 50% igntion cut mean?
Does it means that 1 ignition out of 2 is done?

Correct, half of the ignition pulses for a given engine cycle will be cut, so a 6 cylinder engine will only fire three times. This is randomised, so you may have fire, fire, cut, fire, cut, cut, fire, cut rather than all of the even or uneven cylinders being dropped.

Stephen Dean wrote:Correct, half of the ignition pulses for a given engine cycle will be cut, so a 6 cylinder engine will only fire three times. This is randomised, so you may have fire, fire, cut, fire, cut, cut, fire, cut rather than all of the even or uneven cylinders being dropped.

Understood now, thanks for the info.