Fail noob question: What should target AFRs be? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 06-05-2010, 11:22 PM   #1
Want fries with that?
Thread Starter
iTrader: (3)
 
Join Date: Oct 2009
Location: Twin Cities, Minnesota
Posts: 2,023
Total Cats: -1
Default Fail noob question: What should target AFRs be?

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.
rider384 is offline   Reply With Quote
Old 06-06-2010, 12:37 AM   #2
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,326
Total Cats: 1,926
Default

Quote:
Originally Posted by rider384 View Post
how does one know where AFRs should be at for a specific pressure?
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.
Joe Perez is offline   Reply With Quote
Old 06-07-2010, 09:34 AM   #3
Senior Member
 
Join Date: Nov 2007
Location: Belgium
Posts: 939
Total Cats: 59
Default

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


WestfieldMX5 is offline   Reply With Quote
Old 06-07-2010, 10:00 AM   #4
Senior Member
iTrader: (1)
 
Join Date: Sep 2007
Location: Trenton, NJ
Posts: 1,125
Total Cats: 0
Default

This is what I use:

ArtieParty is offline   Reply With Quote
Old 06-07-2010, 10:02 AM   #5
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,895
Total Cats: 1,792
Default

and these are mine:

Braineack is online now   Reply With Quote
Old 06-07-2010, 11:09 AM   #6
Senior Member
iTrader: (14)
 
Join Date: Aug 2008
Location: Tinley Park, IL
Posts: 1,488
Total Cats: 0
Default

Minez:

Name:  afrtargets.bmp
Views: 229
Size:  576.1 KB

Yes, my car like the gas. It wont idle any leaner without popping.
lordrigamus is offline   Reply With Quote
Old 06-07-2010, 12:11 PM   #7
Senior Member
iTrader: (4)
 
Join Date: Jan 2008
Location: Falls Church, VA
Posts: 1,367
Total Cats: 16
Default

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.
ScottFW is offline   Reply With Quote
Old 06-07-2010, 12:15 PM   #8
Senior Member
iTrader: (2)
 
Join Date: Mar 2006
Location: MA
Posts: 885
Total Cats: 2
Default

fwiw, mine are very similar to brain's on a 1.6 greddy with begi downpipe and 2.5" turbo-back
devin mac is offline   Reply With Quote
Old 06-07-2010, 03:08 PM   #9
Newb
 
Join Date: Mar 2008
Posts: 20
Total Cats: 0
Default

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 *****)
Attached Thumbnails
Fail noob question: What should target AFRs be?-afr-targets.jpg  
malachi_fox is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
MS PNP requires reading and following directions??? satisfied MEGAsquirt 141 10-06-2015 11:44 AM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM
why is my car running like pewp? (tune/datalog) itsMikey MSPNP 3 09-28-2015 07:40 AM
TPS based AFR map for better mileage (?) elior77 MEGAsquirt 30 09-23-2015 07:38 PM
ME221 Now has Autotune and Long Term Fuel Trim Tables Motorsport-Electronics ECUs and Tuning 0 09-05-2015 09:02 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 01:05 PM.