Yes, I have my flamesuit on and will openly admit that I have never tuned a FI car and have nearly no experience with MS.

That being said, how does one know where AFRs should be at for a specific pressure?

Car is a 96, Brain built MS-I.

 

Experience.













In the cruising cells (everything that's neither boost nor idle) the low to mid 15s are a good target.

At idle, some cars like stoich (14.7) while others prefer to run a bit richer (mid 13s), which is largely a function of injector size.

In boost, you'll want to enter at the high 13s and taper down into the 12s at the top of the table. This is just a general guideline- you'll need a dyno to find the schweet schpots.

 

Here's a good thread to start reading.
https://www.miataturbo.net/megasquirt-18/anybody-mind-post-their-afr-target-tables-29956/

You'll notice that nobody uses the same tables as every car is different. I'm using this currently.
I'm running ±160kPa so my table only goes up to 183kPa

 

This is what I use:

 

and these are mine:

 

Minez:



Yes, my car like the gas. It wont idle any leaner without popping.

 

Several respected tuners of naturally aspirated motors have said that the best range for power and safety at WOT is within a couple tenths +/- of 13:1. It seems like a bunch of you run leaner than that in your 100 kPa row and I'm curious what the reasoning behind that is.

 

fwiw, mine are very similar to brain's on a 1.6 greddy with begi downpipe and 2.5" turbo-back

 

here's mine...I don't know how to get it to JUST view the AFR target window like you guys did. I'm non intercooled, so AFR's are naturally be a bit richer than those who are(those lucky low IAT seeing *****)