1ZZ COP dwell times - these look ok?

Hi all,

Just looking at the dwell times in my Link G4+ Xtreme and just sense checking a few of the dwell tables I have found for the 1zz COP, I have attached a shot of the table I have setup using data from someone on the MR2OC who has tested them with a scope.

My ignition delay is currently at 80us with a spark duration of 1.0ms although I think I have seen a few run them at 0.7ms spark duration.

Just wondering if these seem to be sensible - have previous run the engine fine with the 12v dwell at around 3ms, 13v at 2.2ms with 14v at 2.0ms.

Wasn't sure what others are using in their builds as there seems to be a fair mismatch of tables as I think there are a couple of different 1zz coils - they seem to be a popular choice to use to swap to COP.

Hi David,

The 1zz coils do not require a large amount of dwell, we have found the are also pretty sensitive to over dwelling and result in damaging the coil and the coils getting quite hot.

The dwell we run, which has been scoped/measured and is very successful in many high powered 4G63 and JZ motors we tune. Close to yours although a little lower at 14v

8V 6.3

9V 5.3

10V 4.4

11V 3.8

12V 3.2

13V 2.7

14V 2.4

15V 2.2

Thanks for that - will amend my dwell times, is the spark duration of 1.0ms ok or shall I reduce that slightly?

Did you verify the ignition delay? 80 uS seems high (typically I see 40-50uS)

The way you do that is to lock ignition timing (either a test mode in the ECU software, or by setting the igntion table to a constant value like 10 or 15 degrees). Then using an inductive timing light (use a plug extension so you are picking up the coil output), you verify the timing at idle -- now as you rev the engine up, the timing should not change -- if it does adjust the ignition delay until it doesn't.

The reason this works is that ignition timing is in degrees of crankshaft rotation and thus the time varies with engine speed, but the igntion delay is a constant. If it's not the right constant, then the timing will vary with engine speed.

Spark duration of 1ms is fine.

As David said though you will need to check your delay as this can vary.

Thanks guys, will look to check the delay - I am using a basemap from the Link dealer I purchased my ECU from, they sent me over a basemap for a 1zz they had tuned - finding a few issues with some of the settings they have used though so going through everything!

Will put a timing light on the engine and check to see if it moves - might drop it down a bit anyway - trying to compare what is a 'normal' range and can work from there.