Mapping - Advice...

[eternalife]

I am looking to get my car mapped soon and have a number of questions which I would hope some people may be able to offer advice on...

I am currently using a Emerald M3DK Ecu - which is capable of being upgraded to a K3 so that the ECU stores three maps which are switchable from inside the car - on the fly using a dashboard switch - via a configurable voltage input.

Has anyone any experience of this?

Is it worth upgrading having done?
Obviously this question is slightly open ended - although I am not too familiar with mapping and therefore, I currently believe a single map can be produced which can be geared towards MPG at certain throttle positions and RPM whilst also being geared towards power at other throttle positions/RPM?

Will a map which is geared towards MPG be 'grossly' different from one that is aimed at yielding maximum power potential?

Would it be possible to have a map which is geared primarily for power from 70%-100% throttle and between all other throttle positions be geared for fuel economy? Likewise, can the same be done for varying RPM - i.e. mapping for power above 4500rpm or something similar?

Does anyone have a 'single' map that varies its bias from MPG to Power according to Throttle position/RPM?

Can anyone also offer advice on how this will effect the behaviour of the engine and the cars drivability? - i would imagine the bias from MPG to Power can be done so in a gradual manner over many 'sites' thus making the car perfectly drivable?!


Finally, what experiences (if any) do people have of using Dave Walker for mapping purposes?

Any recommended mappers for Emerald ECUs?


Many thanks in advance.

 

[edde]

Dave Walker is superb if you have the oportunity to use him then do.

Regards the mapping best talk to him but realy for low threottle use the normal road cars are mapped for good mpg for higher rpm there mapped for power depending on demand is how they map for a race car fuel economy isn'ty as much an issue usually so they use one all out power map

As for if you should upgrade humm depends on what you use the car for personaly for a normal road car withou turbo etc I woulnd't see any real point.

 

[stan*]

negative edde...

A race car will run part economy on non full load conditions. Consider a Le Mans car, they run circa 16:1 AFR when not on WOT....helps conserve fuel.
As for economy v's power, its not RPM based, but load based. You only need max torque on full load. Any thing else can be for economy.

Edde have you ever used Dave Walker??
What are you basing your recomendations on??


Eternal--you'll be fine with a single map, no need in a second map unless your running boost and/or have traction issues.
With proper calibration stratergies applied you can have the engine perform as required for specific conditions. As above, max power is only required on full load (load being defined as % of potential max power being produced, so it follows at 100% load (WOT), we map for full power).
on cruise conditions, say 20-50% load and 2500-4500rpm we can set to run lean(er). Typically a target AFR for non-max-power areas would be stoich/14.7:1...as this is the theoretical point of complete combustion (note, THEORETICAL). It is also the optimum for a 3way catalytic convertor to operate. However on cruise conditions we dont do emmisions tests lol, and an engine will SAFELY run on the lean side of stoich to about 15.5-16:1 based on my experiences of mapping. Theoretically you can go to about 17:1....it all depends on the crown design etc etc but basically you can go as lean as the engine wnats to (it will start mis-firing and torque will drop sharply off). SO on cruise conditions we would set to circa 15.5:1. Every where else I tend to aim for stoich so as to maintain "crispness".
As for between these afr changes onthe map, its best to gradually bring them in over maybe 3 sites, so as to stop jumpiness and jerking when passin g over these sites. you shouldnt notice it when driving.

Ign timing will also influence fuel consumption but not to the same extent as AFR.