Ignition Timing


8krpm

Member
Joined
Jan 3, 2017
Messages
71
Car(s)
EK Civic
I'm trying to get my head around how to "correctly" set ignition timing.

I understand as the RPM band increases the plug needs to ignite sooner to accommodate for a faster moving piston, however I'm trying to understand what indicators provide the information that the timing has been set suitably for your build? Would you be looking for a smooth idle, certain noises while the engine is being revved? How does the distributor/computer know that it needs to increase timing as the engine starts spinning faster (since the distributor is mechanically controlled)?

I can understand on a stock build you can set ignition timing as per the service manual, however, how do you know where to set your ignition timing if you have a 300hp build running pump vs a 600hp build running E85?

Yes I know "your tuner should probably know", but this is more for my information on the topic. I'd like to know a bit more about the tuning side of things and ignition has always been an enigmatic subject for me.

Heaps of questions, if someone could help or point me in the right direction that'd be great.

Thanks.
 

Last edited:

chrismc_DC2

Member
Joined
Jan 2, 2009
Messages
462
Car(s)
2000 UKDM ITR. CW factory std
Setting the base ignition timing is obviously a simple case of jumping the service connector & turning the distributor so the idle ignition advance is within the factory range (16 +/- 2 degs on my B18.

The factory ECU has built in maps for the fuelling & ignition that are pre-programmed. These commonly use factors such as RPM, throttle opening & temperature (water & OAT) to determine what ignition value to match to what injector duration to give best efficiency and power/economy depending on whether the car is running on part throttle or heavy load.

The ignition map is set within the ECU. Fuelling depends on whether the car is in open loop or closed loop.

Have you tried googling the answers to your questions? There will be many articles to assist your understanding....
 


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