Engine management mapping

[doughman]

So I’ve got the car running (duratec with throttle bodies) on a base map, emerald ecu. I have it reading the lambda sensor. Have been playing around with the map slightly, light throttle normal driving seems to okay reading about 12.5 afr. I know this could be a bit rich for driving around but it drives nice and smooth.

At full throttle it’s reading quite lean 16-19 afr. I have richened it up which helped a bit, but do I basically keep putting fuel into it at WOT until the afr is reading around 12-13? Is it normal to read this much when it’s getting maximum air in?

The injectors are quite large large for the spec it’s running. 440 injectors on a fast road engine maybe too big but that doesn’t explain why it’s lean at the top end? So basically is it a case of getting the afr right at full throttle?

[theduck]

Thats FAR too lean for wide open throttle. Yes you need to add more fuel, though I suggest paying someone to map it before you blow it up!

[wildo105e]

Emerald has an auto tune facility. Will this not get you closer for fine tuning after. I would imagine emerald have a map for a duratec that will get you pretty much there.

[Graham]

as i understand it for the auto tune to work properly you need a suitable wideband sensor and the map fairly close

[doughman]

Yea it does have an adaptive function but as said I think it needs to be pretty close and it needs quite a bit of driving before it makes adjustments

[Forest_rallying]

If I were you I would get it to Dave Walker or Northampton Motorsport for a proper setup and RR tune.

[doughman]

I agree with getting it set up properly. But I’ve done everything else on this car myself, I might as well give this a go, learn about the software and how it works. And if something goes wrong in the future at least I have an idea how to fix it.

[wildo105e]

I will be pretty much at this stage in the next few weeks. so i have a lot of "book theory" i have had the engine running before on Megasquirt and what you say is exactly right. If you are running lean then effectively you need more fuel to get the AFR in a suitable range for a petrol engine at WOT. It is also my understanding that at WOT you will also tend to run a lower AFR ratio in the 13's etc.

[daniele]

my 2cents thoughts
In the past I blown an engine trying to map on the road. Dta base map was totally out. It is also true that time WB sensor kit were not easily available.

Before mapping, I read a lot of books and I was well aware of what an engine likes as fuel and ignition.

So, my cons are

if you decided for diy mapping, call a friend with the same knowledge and passion as your. You cannot drive and map, or at least not safely , both for the engine and your health.
If you decide to go for roller session, it is the best. After that, you'll anyway put the hands on the map. There are some cells that cannot be mapped decently on a roller. You'll discover that the map will be too rich in some areas, especially on partial throttles. You'll also change correctors for air and water temperature, acceleration and the like. Probably ign advance will not require big adjustments

In turn, after dyno session, you can play with mapping.

[katana]

A dyno mapping session is money well spent - you could drive hundreds of miles and get an 'ok' map but there are few places to do sustained WOT runs so it'll still be guesswork there. If the ECU has data logging function it makes like a bit easier but it's still drive, stop look at log, adjust, drive, stop look at log, adjust, drive repeat etc. Sometimes specialists do do a better job than talented DIY'ers

[Graham]

even if you can get the mixture right-ish, its impossible to get the timing correct mapping on the road