Ignition tuning - via log driven approach
 

Hi guys - first off I'm a total newbie when it comes to tuning so please take my observations and responses from a said perspective, would appreciate it better if you could point/correct me towards the proper direction.

I'm trying to improve full and partial throttle performance by advancing timing. I'm on Wayno's 98RON ROM with stock gutted headers and a catback exhaust on RON97 fuel. Since flashing to Wayno's I've captured about 7 hours worth of logs and loaded it into a visualization tool to help me make more sense of the data I've collected. I typically do city driving, with some highway and the occasional canyon runs.

So I did a dyno run very recently and this is what I've found: IAM is reading at 1 with some minor knock after 5k rpm, with quite an amount of knock past that - about 2-4 degs taken away. However I'm not sure what I could do to improve that situation other than reducing timing at those areas of the map so I'm letting the ECU handle it for now.

https://i.imgur.com/uE6mboj.png

Below is a log of an hour plus drive around city and highway with traffic. IAM is at 1, and FBKC at 0. This looks good to me, which I can probably improve on timing based on these results.

https://i.imgur.com/Ud4KWPV.png

Many advise increasing timing half or 1 deg at a time and check back for FBKC/IAM drops. Now this is simple enough but increasing timing blanket wise doesn't make sense - after all I'm already seeing FLKC at WOT at more than 5k. Increasing timing at sections where the engine doesn't go (low RPM, 1 load) won't do a thing either. So back to the logs again...

This is a heatmap of RPM and load of my logs combined with these filters in place:

1. >=1000 RPM
2. On throttle (>=15%)
3. Oil and coolant temp >=85C
4. Loads >= 0.25

https://i.imgur.com/YCUyMPl.png

My approach is to apply additional timing at the solid blue areas, as those areas are the lines that the engine goes (again, not advancing anything above 5k at high loads)

https://i.imgur.com/uD6F9bI.png

Now I know our engines will be knock limited at WOT so that's easy to tell whether if I'm advancing too far. But would I be knock limited at partial throttle I'm also aware there are methods to calculate or estimate MBT - that's all I know for now, I'll need to do more reading...

Get your fueling coreect first
make sure afr and comnanded afr are close when full throttle
make sure ltft is low throughout rpm range
ie get you maf scaling correct


Then when fueling correct tackle the knock
thisxwill usualky involve removing timing in pronlem areas or increasing the amount of DI fueling

Also consider that in lower load areas you could advance past MBT and lose power. My advice would be to pull out timing at WOT to resolve where it's pulling timing and leave it at that.

General rule of thumb is to have the minimum timing needed to make the torque for any given situation. You can't really calculate MBT without a dyno and TBH does it matter that much when not WOT?

This ECU does it's ignition maps in 0.35 deg steps.

MAF scaling is as good as it gets - LTFT is about 2-4% which is alright. AFRs go from 11.8 to 11.3 from 5K to redline at WOT... fuelling is tad rich but should be safe for people who are still figuring out things.

Looks like I'm SOL without a dyno then, as I may unknowingly pass MBT without knowing power outputs.

My counterpoint is that we don't drive with the pedal to the floor all the time, optimizing timing at non-WOT is basically maximizing power for all situations. But would love to hear your point on why you'd think it's not worth the effort?

Also, assuming if I can get to a dyno and do timing runs all day... what do you think of the methodology I described? Or are there other methods tuners approach this problem with?

Because if you're not WOT and want more power, put your foot down more. The argument could be made that obviously you could use it to maximise economy, but I think you'd want to tie that it with cam timing more than (but alongside) ignition timing. Again, you need a dyno for that.
The general method that I've learnt is generally
1. Cams
2. Fuel
3. Timing

Non-WOT is hard to dial in unless you have live tuning as you can't hold at a load region and adjust. So all you get is power runs. There is some theory that you want a smooth ignition map so perhaps you just total up the timing maps (beware of different axis settings), get your WOT timing sorted and then try and smooth in the timing from high load cruise (around 0.7/0.8 load) and WOT.

That makes sense, given the limitations that we're bound on stock ECUs. A few posts here also reference the smooth, characteristic curve of the timing map.

Thanks @Kodename47 for the tips. Will give it a try in due time and report back those changes.

Just for kicks I did some on-the-road pulls with RON100 recently. Knocking occurs far lesser above 5k RPM but when it does, it would still pull 3-4 degrees away - strange. Will post up the graph later.