Ignition Timing Question.

[k4nnon]

Hey all LinkG4x PnP user here with my USDM 2006 EVO9. I have an ignition timing question that I am unsure of. Self tuned and doing well so far on street and on dyno. Car is on ethanol and content is reading about E72 currently. So Iv recently started further tuning my Boost and ignition tables after having a decent base map. My starting ignition map is just the base startup ignition map provided from Link only I initially lowered upper end quite a bit to build my knock threshold tables. Now going forward, I did a few curiosity searches about what ignition timing numbers the evo 9 likes and I have noticed that other peoples ignition maps are running a lot less timing during peak tq than I am. Now these other maps are from older posts and users are using EcuFlash and EvoScan if that makes a difference. But what im seeing in other ignition maps are timing numbers around the 4* and 5* during peak tq and then the added timing going towards redline. Looking in my current ignition map I havent changed anything in the peak tq region as of yet but the stock provided map from Link has numbers from 25* down to about 15*. I have not seen any knock in my logs but wondering if I would see a benefit by running less timing in this region and how to go about finding that sweet spot. I understand the adding timing to find the MBT but how do I go about the lesser timing in peak tq region if it is beneficial. Would like to build the best ignition possible as we would all like to but if anyone has any input on this I would love to hear it thankyou.. Ill post up current map and pictures of other timing maps for reference. I will mention that i did come across a couple maps with higher values but the question is which is correct? or do I just continue with my current map and progression?? Thanks again!!

 

https://drive.google.com/drive/folders/1S3uG6q3h0MHMiIYy0mWX0BABzi37R8n_?usp=drive_link

[Deondré Williams]

Timing at peak torque will depend on the fuel you're using, boost you're running & where it comes in, and whether or you have built engine or not and would like to push things. If you have access to a dyno, you can start with a lower timing at peak boost and increase gradually to see what gains it gives. If you turbo comes in hard, say under 4000 RPM, be a bit careful adding a bunch of timing at peak boost.

[k4nnon]

44 minutes ago, Deondré Williams said:

Timing at peak torque will depend on the fuel you're using, boost you're running & where it comes in, and whether or you have built engine or not and would like to push things. If you have access to a dyno, you can start with a lower timing at peak boost and increase gradually to see what gains it gives. If you turbo comes in hard, say under 4000 RPM, be a bit careful adding a bunch of timing at peak boost.

Hey thanks for the response. I understand all of that already, just wondered if there was a proper way to go backwards with timing to find the best spot or if it’s always the advance method. I guess ultimately what I can do is set everything under boost levels as stock and everything above to 0* and add from there to find the best timing for pk tq then use the add method towards redline to fill in the rest of my map. Looks like that’s the rout. Thanks again for the response. 

[Hodgdon Extreme]

21 hours ago, k4nnon said:

if there was a proper way to go backwards with timing to find the best spot or if it’s always the advance method.

 

On 7/16/2023 at 8:37 AM, k4nnon said:

im seeing in other ignition maps are timing numbers around....

I used to run dynos for the OEMs. I know of no other way to develop ignition tables other than hammering out tests on the dyno. MBT is pretty easy and can be done on a chassis dyno pretty well; but if you want to minimize pumping losses and BSFC at less than WOT the way the OEMs do - it'll need to be done on an engine dyno - or take lots of time and fuel doing it on the street empirically.

I suspect you are already well aware - but it bears repeating: be super careful reading into other internet people's ignition timing values. Did they truly get the trigger offset and ignition delay correct? Are the timing marks on their balancer even accurate? Are yours? Do they shine the timing light on the balancer and look at it from the same angle as you? There can easily be 5º or more accumulated error based on these factors.

[k4nnon]

44 minutes ago, Hodgdon Extreme said:

 

I used to run dynos for the OEMs. I know of no other way to develop ignition tables other than hammering out tests on the dyno. MBT is pretty easy and can be done on a chassis dyno pretty well; but if you want to minimize pumping losses and BSFC at less than WOT the way the OEMs do - it'll need to be done on an engine dyno - or take lots of time and fuel doing it on the street empirically.

I suspect you are already well aware - but it bears repeating: be super careful reading into other internet people's ignition timing values. Did they truly get the trigger offset and ignition delay correct? Are the timing marks on their balancer even accurate? Are yours? Do they shine the timing light on the balancer and look at it from the same angle as you? There can easily be 5º or more accumulated error based on these factors.

Hey thanks for the input, All true statements and especially about the forum stuff. I think Iv decided to develop my own ignition tables the next time I get on the dyno. Easiest best method. Thanks again for the input.

[Deondré Williams]

59 minutes ago, Hodgdon Extreme said:

I suspect you are already well aware - but it bears repeating: be super careful reading into other internet people's ignition timing values. Did they truly get the trigger offset and ignition delay correct?

This is very true.