me!
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| posted on 17/3/13 at 08:53 AM |
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AFR/Spark table sanity check please!
Hello all.
Now that I am MOT'd + taxed in time for the summer, I could do with getting some zeros and ones into my engine. It's a 2.0 zetec, GSXR 600
TB's, standard cams, 4-2-1 exhaust, on microsquirt (similar to MS2) running the extra code. I have an AEM wideband connected to the MS as well.
Alpha-n fuelling algorithm, but I do have a map sensor which I intend to use for acceleration enrichment, fatbaldbloke style
(http://www.msextra.com/forums/viewtopic.php?f=4&t=25222).
It runs ok for trundling along to the MOT station and back, but now I want to get some more sensible values in there. I haven't been able to
find any AFR tables for TB'd zetecs despite a bit of searching. Could somebody have a look at the below and check whether this is a sensible
starting point? Then I plan to use mega log viewer and the VE analyse function.
AFR, sparks, and current VE tables. Not very clear, but if you open the image and zoom in a bit it is readable. VE table is miles out but drivable at
low load/rpm:
 
Tuner Studio Tables
AFR table alone:
 
AFR table
I think the AFR may be a touch high in the cruising area, but I don't suppose it'll do much harm at low throttle angles.
Let me know what you think or post up yours if you can!
Thanks all.
Craig
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ashg
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| posted on 17/3/13 at 09:40 AM |
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your ignition table looks pretty off(well untuned) get a couple of other known good zetec ignition maps from another well tuned 2.0 zetec from any ecu
system, doesnt really matter if its tb's or not then use ve analyse live(its really worth the $49) to get the fuelling somewhere close to what
it needs to be. once you have the fuelling pretty good you will need a pair of det cans you can then drive it and dial more more or less advance in
with blowing it up
the afr table looks goo enough to get started, dont forget to setup the acceleration enrichment so that it dumps extra fuel in if you stamp the
throttle open to speed up fast.
remember ve tables are for nice smooth transitions between load cells and acceleration enrichment is for fast throttle demands.
Anything With Tits or Wheels Will cost you MONEY!!
Haynes Roadster (Finished)
Exocet (Finished & Sold)
New Project (Started)
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matt_gsxr
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| posted on 17/3/13 at 10:21 AM |
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From what I understand you can weaken it down a bit at the high RPM low load sites. Basically these will only be encountered on the over-run so
leaning off gives an opportunity to clean up the spark plugs. If you lean off too much you will get bangs and pops, which is personal preference, but
probably indicates you have gone too far. You can't do any damage leaning off low throttle sites.
If you want to pass the MOT then you might need to be in an area of 14.7AFR at idle.
My one experience of megasquirt with Zetecs (ChrisLeary) suggested that they can ignite pretty much any mixture (unlike bike engines at low throttle
RPM and low throttle openings) so I don't thing you will have a problem at 14.7.
Regarding the spark table, this is one of those things that I have struggled with too. The advice of duplicating a known good one is probably
sensible, but make sure you (and they) have got the trigger wheel offset set up right and if you get any detonation then sort it straight away
(don't hope it will go away!).
Normally if you have a weak mixture on the overrun then you also have a more advanced spark (40deg) as this burns the weak mixture better. These
weaker mixtures are partly for fuel efficiency, so I guess you can ignore them (like you have).
Matt
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me!
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| posted on 18/3/13 at 06:03 AM |
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I think I'll put in the spark table from here: http://www.locostbuilders.co.uk/viewthread.php?tid=156113 next time I have a play. Can't be
too bad if an engine tuner says it's 95% there. I'll add a bit of advance at high speed/load as suggested, but only when I'm
confident it's not all going to go pete tong.
Good point about the high speed low load stuff, it really doesn't need to even be stoichiometric. I'll back it off until it starts to pop
a bit.... might leave a few in for good measure :-) I'm already MOT'd, and I'm on visible smoke only so I can get away with quite a
lot on my car. I have it slightly rich at idle as it seemed to run best like that, but I was stunned at how far either way it would run- I had it lean
off the lambda gauge scale, so 18+ when I first started.
I thought it was best to turn off AE when tuning initially? It's off at the moment and I do have a lot of lean spikes at every throttle prod.
Can VE analyse/live cope with it on? It would be nice to have it on to be honest.
Also about the trigger wheel offset- I'm using the Ford sensor and location, looking at the back of a Ford flywheel, running through an EDIS, so
I'd assumed it would be bob on. Is this not the case?
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rdodger
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| posted on 18/3/13 at 03:21 PM |
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Have you considered getting a rolling road session?
I messed with mine for ages 9supercharged mx5), then went to see Dale at http://baileyperformance.co.uk/ and he had it sorted in a couple
of hours. Well worth the money.
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me!
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| posted on 18/3/13 at 09:20 PM |
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Yep, it's definitely on the to-do list, most likely with Bailey performance as well. But I'm getting married in a few weeks and I'm
hoping to drive there in the Stylus, can't afford a rolling road before that! Plus I quite enjoy all the farting about to be honest!
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