Timing when using NOS and Megasquirt question

When using Nitrous Oxide on an NA engine do you have to have a controller to retard the timing when injecting NOS?

Also, does anyone know if you can use Megasquirt to control NOS alongside a standard ECU (ABF)?

 

How much nitrous?, anything over a 50 shot will need ignition retarding.

 

Also if the engine already is close to det on petrol, then a shot of gas with the right fuel ratio will only push the engine it into det.
NOS causes fast burn and so you require less ignition advance to achieve maximum in cylinder expansion 10-14 deg CA.

You can configure the MS to run laughing gas and then set the software similar to this screen shot from an example.



Here you can determine how much offset spark advance can be dialled out when nitrous is activated.

 

Maximum would be a 50bhp shot to a standard ABF (digi 3.2)in a MK2 golf.

My idea was to stick with the oem management but use my megasquirt ecu to control nos as I have a MS ecu lying around and dedicated nos controllers are expensive. Im guessing using this setup means I can only control nos and not timing with the megasquirt. Would this work?

I have no idea if the standalone nos controllers (like wizards of nos min/max controller) also control timing?

 

I have a WON Max Extreme V1 and it doesn`t control timing. It does however have selectable ramp rates and power for each gear so you can bring the nitrous in softly rather than one big hit (less chance of setting off knock).

With the Megasquirt, you will have to wire that up to give your car full time timing control to allow it to retard with Nitrous active.

If you`re only using Nirtous in specific instances, like 1/4 mile runs then race fuel could be an option?.

 

ok so the WON system only controls NOS and additional fuel. does it work off a time basis or RPM? so for example if NOS is activated at 3000rpm does the controler inject 30% NOS then at 5000 it reaches 100% progressively OR is it time based so at 3000rpm it injects 30% NOS then after 3 seconds it progressively injects 100%??

does that make sense or is my GCSE failed English showing?

Toyo, does MS inject NOS progressively or all in one go?

 

It`s time based, but has rpm and throttle thresholds as well so you don`t inject too early.

 

The megasquirt is 'told' Nitrous is activated via a switch. You can calibrate the logic:

• Switch to another calibrated table for fuel control
• Tell the ignition table to switch to "spark 2" after a calibratable delay

So if you run a system as suggested by Keith then you can remain on table 1 for fuel and switch to a spark table that progressively retards spark away from det as the burn rate speeds up.

 

interesting, So If I were to fit nos to my ABF I am better off getting a dedicated NOS controller to progressively inject nos.

If I were to use MS then I should get my engine running on the MS first then mess about with nos control on it. The MS has fuel control but is unable to progressively inject nos like the WON controllers. is this correct?

Keith, is it worth going for the Extreme controller or is the minimax good enough? Also, how does the controller know what gear you are in?

 

engine speed in relation to vehicle speed.

 

It cannot control nitrous but can act on base engine control parameters if it is told a Nitrous system is present.