Engine Worries

[Rich H]

Erm, yes...

[robin]

I have a MS2 built ... just lost interest because I couldn't find my way through the maze that is the MegaSquirt s/w ...

Cheers,
Robin

[Shug]

Good luck with the Emerald - I can't say I had much luck with any of the ones I've used ... it's one thing to use it for a sprint/race car where you only need full throttle from 2,000 RPM up and you don't care if it idles at 1,500 RPM ... but on a road car they are a PITA IMHO.

Sorry Robin, but that's pish mate. Mine behaves perfectly - you just have to accept the fact that it takes ages to get things like the cold maps right. Mine (on TBs with no IACV) sits on a beautiful 8-900rpm idle all day

[robin]

Try taking it up a mountain ...

Robin

[Shug]

Okay, but I'm sure you can plumb MAP sensors in now, if that's a problem. Certainly it uses them for turbo installations with the K3...

[Rich H]

even the MS has an input for atmospheric pressure if you need one, the emerald must have the same option....

[roadboy]

Yup,

No reason why you can't map in using MAP signal. Just convention dictates that readily available maps are mapped by TPS signal predominantly.

Dan

[Rich H]

?Eh?

Even my Pikey Porky MS 1 unit can make you a map with MAP/RPM and targer AFR not TPS/RPM, there is an option of RPM/TPS but its definatly not reccommended. Surely the Emerald must be the same?

[tut]

Taking it or towing it...........?



tut ps only just noticed that it made you wet yourself.

.

[robin]

LOL @tut ... that was a good day out despite the chaos of the towing over the mountain

My beef with the emerald (especially the very latest) is the sheer amount of data that it needs to run your engine properly. There must be 8 factors that influence the final injector pulse width and most of them are lookup tables with 10 or more interpolated positions. Perhaps you're all a lot smarter than I am, but I cannot see an easy way of properly filling in these items so that they interact correctly in most operating conditions. Worse, I don't believe the interactions between all these items is properly documented. Sure, Dave Walker can map a car on the rolling road in a couple of hours - I've seen him do it - but he doesn't really address anything other than the main ignition and fuel maps. If someone has proper documentation for the K3 (not the crap that comes with the ECU when you buy it) I would love to see a copy ...

But it's horses for courses - as I said earlier - if you want to make a race car, you can do it with relative ease and moderate expense - but unless you have a lot of time to spend on fine tuning and a very methodical approach (which is hard when you cannot control the ambient factors very easily), I'll take the OEM ECU any day of the week - and if I had to choose an aftermarket ECU for a car running on a single throttle body I would be looking for one that uses MAP or MAF as primary load indicator with automatic correction for all the ambient factors (physics is, after all, physics ).

Cheers,
Robin

[mwmackenzie]

DTA can do either or.. I had to use it on MAp when my TPS broke...

Mark

[Shug]

Fair points Robin - I guess you can't please everyone. The Emerald can be mapped to run everything beautifully in all conditions, but as you say, it's a lot of work. I guess that's why the mapping and development for OEM ECUs is soo bloody expensive! What I will say is that a lot of the tables have intelligent default maps in them, which should only really need tweaking (cold start/fuelling being the most obvious) I mean, I can map the VVC mech with revs and load, but it's set on revs only (with all the load sites copied), as TBH, it'll make a minute difference mapping it on load as well. So, the complexity is there, it's up to you whether you want or need to fiddle with most of it.

I think the choice of a TPS as a primary input (although you can use MAP too) was down to the initial design of the ECU as a cheap unit to power multiple throttle body installations. in 90% of single body situations, the TPS sensing is fine - certainly it's more reliable (if not technically as accurate) as MAP, if the plenum in question is on the front of a cammy engine - the pulses can confuse a MAP sensor more easily than using TPS.

I love my Emerald Has to be said that Karl and Dave at Emerald are also two of the most helpful guys you could hope to meet - reinforced by my experiences with putting TBs on a VVC engine (at the time, one of only 2 known in the UK - certainly with an Emerald) When Karl took plenty of time to go through my problems getting it started - despite making no money from the process. Top lads

[Rich H]

So IAT probe swap first then?

[Shug]

If he's cleaned the filter and IACV, probably

[hiscot]

Okay, but I'm sure you can plumb MAP sensors in now, if that's a problem. Certainly it uses them for turbo installations with the K3...

you always could my old emerald that came with a supercharged engine uses a map sensor
for bario corrections its just a cheap fiat sensor