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Pressure volume cycle and Cylinder pressure diagram

EFI Tuning Fundamentals

Discussion and questions related to the course EFI Tuning Fundamentals

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Here i attached a pressure volume cycle and cylinder pressure diagram from my friend PLEX PCM1000 tuning his machine engine.

In your video shows the complete pressure volume cycle from point 1 intake stroke till piston return tdc point 6 forcing out remaining gasses.

My question

1) Is it possible to tune using this PLEX without dyno? to achieve perfect ignition timing and fuel afr ? without finding MBT using dyno, but instead checking at cylinder pressure cycle to check a perfect cycle?

2) By looking at cylinder pressure vs crank angle , we can find the correct ignition timing for it?

Attached Files

In-cylinder combustion analysis would be very helpful in optimising the ignition timing however it won't help you with the fuel delivery so much. Of course at some point (both rich and lean) the cylinder pressure will tend to drop off but there is a reasonable range of AFR across which torque (and hence cylinder pressure) will be reasonably constant.

Thanks for the reply.

I saw your video on the mentioned, we can't monitor cylinder wall pressure, so you use the MBT technique to achieve optimizing correct ignition timing on torque curve? basically, there are two ways doing it right? thanks. I bring this point because, most dyno shop here are 2WD, most cars like subaru or evo running on 4wd,.

oh yeah , can you move this topic to efi fundamental tuning? i think i post at wrong section. sorry