- Tue Mar 26, 2024 9:43 pm
#67660
Hello,
I took my friends mx5 (2001 mk2.5 1.8vvt) to dyno to make test what can I achieve on stock car using my PnP board. And I found following issue: car runs unstable especially on high rpm, see attached dyno plots. Above 5000rpm there was massive instability.
First I checked #sync loss and found it is 0 all the time. And car runs really bad. Changing fueling, spark, advance, vvt parameters, dwell did not help at all.
came back home and started to dig in the logs. Only weird thing I found was RPM spikes to 10000+ on some dyno runs. But only on some, there was no good (I mean good measurements) dyno run out of 10 trials I performed
On second day I tested this car and also 2001 mk2.5 1.6 (non vvt) and on both found the same issue - cars were running instable, sometimes even stalling for few seconds (tachometer drops to 0, then comes back). And #synclosses still 0 on both. Tested both 202310 and 202402 firmware, the same issue
tried changing trigger filter settings, "resync every cycle" OFF, did not helped
Workaround was ... switching to semi sequential. Immediately both cars started to run smooth
I can provide logs and tune
I took my friends mx5 (2001 mk2.5 1.8vvt) to dyno to make test what can I achieve on stock car using my PnP board. And I found following issue: car runs unstable especially on high rpm, see attached dyno plots. Above 5000rpm there was massive instability.
First I checked #sync loss and found it is 0 all the time. And car runs really bad. Changing fueling, spark, advance, vvt parameters, dwell did not help at all.
came back home and started to dig in the logs. Only weird thing I found was RPM spikes to 10000+ on some dyno runs. But only on some, there was no good (I mean good measurements) dyno run out of 10 trials I performed
On second day I tested this car and also 2001 mk2.5 1.6 (non vvt) and on both found the same issue - cars were running instable, sometimes even stalling for few seconds (tachometer drops to 0, then comes back). And #synclosses still 0 on both. Tested both 202310 and 202402 firmware, the same issue
tried changing trigger filter settings, "resync every cycle" OFF, did not helped
Workaround was ... switching to semi sequential. Immediately both cars started to run smooth
I can provide logs and tune
Attachments
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kind regards
Aleksander
MX5 NC + RomDrop
MX5 NBfl / NB / NA Speeduino PnP boards
Aleksander
MX5 NC + RomDrop

MX5 NBfl / NB / NA Speeduino PnP boards