Megasquirt and emissions

[Chilliman]

If, as I understand it, Megasquirt will control fuelling and ignition to optimise combustion (greater efficiency at any load/rpm/state of mods etc) then is it reaonable to assume that if main and pre-cats are removed the 'burn' will be sufficiently efficient to be within the MOT allowable emission levels ?? Or am I talking (as I often do) complete pish ????

[JonyTVR]

Yup you can set an extra lean map no problems so you could drive it there, lean everything off so performance would be crap by would go through emissions easy and then change it before you leave.

[SILICONE KID]

yes the megasquirt has the option to switch over to Map two which can also be used for nitros,LPG etc..

[Derek Smith]

Chilliman said:

If, as I understand it, Megasquirt will control fuelling and ignition to optimise combustion (greater efficiency at any load/rpm/state of mods etc) then is it reaonable to assume that if main and pre-cats are removed the 'burn' will be sufficiently efficient to be within the MOT allowable emission levels ?? Or am I talking (as I often do) complete pish ????

However, if you drive it on the road not on that specific map and are stopped for an emissions check you must not switch it back to the lean mode.

Thought I'd let you know, just in case.

[SILICONE KID]

Derek Smith said:

However, if you drive it on the road not on that specific map and are stopped for an emissions check you must not switch it back to the lean mode.

Thought I'd let you know, just in case.

My god your boring

[peaktorque]

SILICONE KID said:

My god your boring

You're

Almost as boring as the endless MPG threads that seem appear on the Chimaera forum..............

[SILICONE KID]

SILICONE KID said:

Derek Smith said:

However, if you drive it on the road not on that specific map and are stopped for an emissions check you must not switch it back to the lean mode.

Thought I'd let you know, just in case.

My god your boring

Come on that is ridiculous !"Sorry officer im running to rich but im not telling you about the drug stash in the boot"

[v8 racing]

Chilliman said:

If, as I understand it, Megasquirt will control fuelling and ignition to optimise combustion (greater efficiency at any load/rpm/state of mods etc) then is it reaonable to assume that if main and pre-cats are removed the 'burn' will be sufficiently efficient to be within the MOT allowable emission levels ?? Or am I talking (as I often do) complete pish ????

No it wont, no ecu system is capable of doing what cats do, yes you can lean an engine off where you want too but, the more you lean an engine off the higher the hc's will go, so you pass on the co but fail on hc's! or lambda

[Chilliman]

Thanks Rob, have read everything I can find on megasquirt and was curious about the emissions aspect...

[Alexdaredevilz]

Chilliman said:

Thanks Rob, have read everything I can find on megasquirt and was curious about the emissions aspect...

Try this

http://www.diyautotune.com/

[Chilliman]

Cheers Alex, looks very interesting !!! will take some time to read through it in detail.. Now, where did I put my soldering iron ????

[lwt]

For emissions you need to balance HC vs CO. One will rise as mixture leans, the other as it richens. What you need is Lambda=1 (the MoT measures Lambda and has an allowable band, shown on your print-out. The MoT test is done no load, steady rpm in a stated band, so if you have an adaptive ecu it is easy to set target lambda=1 for throttle sensor positions that correspond to that rpm band. On test, the adaptive will settle lambda once the rpm is steady and you have optimal emissions. Out of that band and on load you can set whatever you want and of course the adaptive bit won't kick in while you are accelerating so your base map can be optimised for power/torque.

Ian.

PS the above works on a KMS, I assume Megathingy is similar.

[blitzracing]

You've missed the important bit (as V8 racing says), you NEED THE CATALYSTS to get anywhere near an MOT standard, however good the ECU is.

[TV8]

blitzracing said:

You've missed the important bit (as V8 racing says), you NEED THE CATALYSTS to get anywhere near an MOT standard, however good the ECU is.

I must be lucky, it gives good power for a 4L and still passes the MOT after taking out the main CAT. Not sure if it is standard or not.