ECUs and Tuning Discuss Engine Management, Tuning, & Programming

Tuning for gas milage

Thread Tools
 
Search this Thread
 
Old 08-28-2010, 03:24 AM
  #1  
Junior Member
Thread Starter
 
turboT's Avatar
 
Join Date: Apr 2010
Location: Rohnert Park, CA
Posts: 75
Total Cats: 0
Default Tuning for gas milage

i really hope im not asking something thats already here, but, how would i go about tuning for better gas milage?
I use a AEM F/IC, and a AEM UEGO.
so really, is it as easy as going into the fuel maps and decreasing the fuel? out of boost the air/fuel ratios are in the 15's.
What would be the most lean air/fuel ratios i should go?
and is there any potential risks by doing this?
Any help is appreciated, or if anyone knows of a site or a post that i couldnt find, please tell me about it
turboT is offline  
Old 08-28-2010, 11:37 AM
  #2  
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,338
Total Cats: 573
Default

leaning the mix out will raise EGTs so make sure you have a good timing map (how you'll do it without an EGT gauge is anyone's guess). probably you'll be ok though.

some emissions info you should be aware of: 14.7 AFR is stoich for gas which means not only is it fully combusting the fuel, it is limiting the amount of other things produced (NOx, HC, CO, etc). So as you increase AFR beyond 15 or so, the combustion temp goes up and the excess air (Nitrogen + Oxygen mostly) gets turned into NOx.

NOx will end up in the atmosphere as smog and acid rain eventually, so bear that in mind next time you stay inside on a spare-the-air day or your paint goes to ****.

That said, some people run up to high 16s but the image below seems to suggest around 16.2 is best economy.

y8s is offline  
Old 08-28-2010, 03:17 PM
  #3  
Junior Member
Thread Starter
 
turboT's Avatar
 
Join Date: Apr 2010
Location: Rohnert Park, CA
Posts: 75
Total Cats: 0
Default

Originally Posted by y8s
leaning the mix out will raise EGTs so make sure you have a good timing map (how you'll do it without an EGT gauge is anyone's guess). probably you'll be ok though.

some emissions info you should be aware of: 14.7 AFR is stoich for gas which means not only is it fully combusting the fuel, it is limiting the amount of other things produced (NOx, HC, CO, etc). So as you increase AFR beyond 15 or so, the combustion temp goes up and the excess air (Nitrogen + Oxygen mostly) gets turned into NOx.

NOx will end up in the atmosphere as smog and acid rain eventually, so bear that in mind next time you stay inside on a spare-the-air day or your paint goes to ****.

That said, some people run up to high 16s but the image below seems to suggest around 16.2 is best economy.

thank you, thats exactly what i was looking for, ill give it a try.
turboT is offline  
Old 08-28-2010, 04:36 PM
  #4  
Senior Member
iTrader: (4)
 
dgmorr's Avatar
 
Join Date: Nov 2009
Location: Toronto, ON
Posts: 1,446
Total Cats: 6
Default

I believe the Megamanual also says you can go as lean as you can get before the engine starts to stumble, buck and/or hesitate.
dgmorr is offline  
Old 08-29-2010, 04:31 AM
  #5  
Junior Member
Thread Starter
 
turboT's Avatar
 
Join Date: Apr 2010
Location: Rohnert Park, CA
Posts: 75
Total Cats: 0
Default

Originally Posted by y8s
leaning the mix out will raise EGTs so make sure you have a good timing map
what would be the ideal timing map out of boost? right now its advanced 14 degrees i think. the previous owner set it. me = when it comes to this :(
turboT is offline  
Old 08-29-2010, 07:55 AM
  #6  
Junior Member
 
secretsquirrel's Avatar
 
Join Date: Dec 2007
Location: Santa Fe, TX
Posts: 101
Total Cats: 3
Default

Uhhh, the AEM F/IC is a piggyback - the stock ECU handles everything out of boost... If you change anything when in closed loop, the ECU will adjust right back to where it wants it...
secretsquirrel is offline  
Old 08-29-2010, 12:39 PM
  #7  
Junior Member
Thread Starter
 
turboT's Avatar
 
Join Date: Apr 2010
Location: Rohnert Park, CA
Posts: 75
Total Cats: 0
Default

Originally Posted by secretsquirrel
Uhhh, the AEM F/IC is a piggyback - the stock ECU handles everything out of boost... If you change anything when in closed loop, the ECU will adjust right back to where it wants it...
no, the f/ic can do it, the shop i go to always installs them on the cars he turbos and he has done this before, i just dont want to pay him to do it.
turboT is offline  
Old 08-29-2010, 02:39 PM
  #8  
Junior Member
 
secretsquirrel's Avatar
 
Join Date: Dec 2007
Location: Santa Fe, TX
Posts: 101
Total Cats: 3
Default

Originally Posted by turboT
no, the f/ic can do it, the shop i go to always installs them on the cars he turbos and he has done this before, i just don't want to pay him to tell me that he did it.
Fixed that for you...
secretsquirrel is offline  
Old 08-29-2010, 05:44 PM
  #9  
Junior Member
Thread Starter
 
turboT's Avatar
 
Join Date: Apr 2010
Location: Rohnert Park, CA
Posts: 75
Total Cats: 0
Default

Originally Posted by secretsquirrel
Fixed that for you...
that works too lol, very true, but i have seen it programmed on his wifes g20, and i asked him about it, he told me what to do, i just didnt ask him about when he said to make sure you have a conservative timing map. he wasnt trying to get me to hire him, he is a friend.
turboT is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
StratoBlue1109
Miata parts for sale/trade
21
09-30-2018 01:09 PM
ihiryu
MEGAsquirt
33
10-08-2015 04:56 PM
tazswing
Race Prep
20
10-03-2015 11:04 AM
The Gleas
MEGAsquirt
3
10-01-2015 09:30 AM
brandonbkd
MEGAsquirt
0
09-28-2015 11:52 PM



Quick Reply: Tuning for gas milage



All times are GMT -4. The time now is 10:05 AM.