Hey y'all, I have been running MegaSquirt N/A for a couple of months & I would appreciate a review of my tune. Eventual goal once I am confident in the tune is to install my kraken turbo kit. I have been tuning over time following tutorials and things but I am very much a beginner to MS. Please don't hesitate to share feedback

Everything had been pretty good until I was messing with my tune today & I had a weird knock event. Seems the car exited overrun but the fuel cut continued for another 5~ seconds. Any ideas what I can do to resolve this?

Knock for each cylinder generally hovers around 3.5~ going up to 5/6 at certain times. I've been trying to pull some timing to keep it in the 3-4 range. Am I being overly cautious or am I risking my engine by consistently going so high?

Any thoughts on the overall tune?

Tune & Log are attached.


Spooky

 

My understanding of this might be limited but where are you getting those knock sensor settings from ? Doesn't look like anything I'd expect on a Miata.
What sensor is this ?
Why is your knock scaling linear for all 4 cylinders ?
Why is your knock input threshold NOT linear ?

Your knock sensor inputs should look like a noisy analog signal, it's basically a microphone. Your log looks like a digital delta voltage signal on an oscilloscope.

 

I’m going to be honest maybe I missed something during setup but I really did not see much about the knock. It is using whatever knock sensor comes with a 2000 NB & the values from the base tune.

The full log looks like what you are describing. It’s specifically this chunk where there is knock reported & it is rather strange.

 

Stock engine/compression ratio? What octane of fuel are you running?

 

Yep stock engine and compression ratio, & I’m running 93 pump gas. I have really only seen the knock like that this time. It looks like the fuel did not start when overrun ended.

 

- The knock settings are incorrect, mainly the bandpass frequency. Try the settings in this post: https://www.miataturbo.net/megasquir...1/#post1651838
- AFR targets are too lean in my book. Contentious point, I know. But you shouldn't be leaner than 12.7 at NA WOT and I wouldn't target more than 15.2 at cruise. Personally, I run 14.7 at cruise. I see spikes in your AFRs around 15.6 which usually indicates slight misfires.
- Turn off EAE until your engine is fully tuned and you have lots of time to play with it. EAE will change your fueling based on what it is attempting to model. The spot in your log you're asking about was caused by EAE as it was at 0 (pulling all fuel, look at the correlation between EAE1 and PW too). EAE is active all the time, even in overrun. Here is a good writeup on the forum: https://www.miataturbo.net/megasquir...eae-ms3-83753/