MEGAsquirt A place to collectively sort out this megasquirt gizmo

N/A AFR targets (yes, again)

Thread Tools
 
Search this Thread
 
Old 10-07-2009, 05:42 PM
  #1  
Elite Member
Thread Starter
iTrader: (2)
 
Oscar's Avatar
 
Join Date: Jan 2007
Location: Bolton, UK
Posts: 3,022
Total Cats: 120
Default N/A AFR targets (yes, again)

I've been pondering about this since I was never a 100% happy with the way my AFR targets are setup in MegaTune. I scaled all the tables down to mapvalues used in a non-forced induction motor, but I feel there's more
to improve. Should I really be dipping in the 12.5 AFRs WOT? Not sure if I could lean that out closer to 13 at full load.

Car makes about 140 rwhp on a standalone, exhintake cam swap and dialed-in adjustable camgears.

My idle MAP is between 30-40 kPa, due to altitude and cam overlap, cruising on the highway is usually 70-85 kPa.

Anyone care to take a look at my current target table and the made I cobbled together so far? I attached both tables in the excel file, aswell as a screenshot of the table in MegaTune.

Thanks
Attached Thumbnails N/A AFR targets (yes, again)-afr-targets.jpg  
Attached Files
File Type: vex
afrBins1_200910072329.vex (1.0 KB, 118 views)
File Type: xls
AFR targets.xls (16.5 KB, 143 views)
Oscar is offline  
Old 10-07-2009, 05:48 PM
  #2  
Elite Member
iTrader: (51)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Spring, TX
Posts: 7,257
Total Cats: 26
Default

Seems awful rich for a naturally aspirated motor. (EDIT: Seems way rich for any motor)

Peak torque with gasoline is going to be between 12.5 and 13.7 if I remember correctly...so you're at the rich end of that range.
gospeed81 is offline  
Old 10-08-2009, 06:50 AM
  #3  
Senior Member
 
WestfieldMX5's Avatar
 
Join Date: Nov 2007
Location: Belgium
Posts: 999
Total Cats: 73
Default

My stock ecu goes 13.8 @ at low rpm, than drops towards 12.8 @ peak torque and goes back up to 13.2 towards redline.
WestfieldMX5 is offline  
Old 10-08-2009, 07:46 AM
  #4  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

I firlmy believe that in an NA car, 13.3 should be the upper limit. I'd put my car at 13.1 unless the dyno suggests I go richer.
hustler is offline  
Old 10-08-2009, 09:13 AM
  #5  
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,332
Total Cats: 67
Default

We've found a lot of NA cars seem to run pretty well at WOT in the 13.0 region.
__________________
Matt Cramer
www.diyautotune.com
Matt Cramer is offline  
Old 10-08-2009, 10:13 AM
  #6  
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

on an N/A car there's no reason to go richer than 14s at less than 80kPa unless the motor suggests otherwise by knocking.
y8s is offline  
Old 10-08-2009, 10:23 AM
  #7  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

Originally Posted by y8s
on an N/A car there's no reason to go richer than 14s at less than 80kPa unless the motor suggests otherwise by knocking.
Only they make more torque with more fuel, independant from spark adavance, lol.
hustler is offline  
Old 10-08-2009, 10:31 AM
  #8  
Elite Member
iTrader: (51)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Spring, TX
Posts: 7,257
Total Cats: 26
Default

Originally Posted by hustler
Only they make more torque with more fuel, independant from spark adavance, lol.
To a certain point...and it starts to diminish around 13.0:1.

I can definitely see dipping below 14.0...I liked 13.8 when I was N/A.
gospeed81 is offline  
Old 10-08-2009, 10:48 AM
  #9  
Senior Member
iTrader: (4)
 
ScottFW's Avatar
 
Join Date: Jan 2008
Location: Falls Church, VA
Posts: 1,361
Total Cats: 17
Default

Some of the numbers look a bit funny because I was originally using a 12x12 in MLV and then just smooshed it down to an 8x8 in Megatune. Tuned to these targets I get about 33 highway mpg. Might be able to lean out the cruise cells a bit more but I'm pretty happy with it overall. On track with stock horsepower, part throttle is somewhat rare for me. Seems I'm usually either WOT or braking, so I don't need to target ~13:1 until 90+ kPa. Often times in traffic when I accelerate a little from a steady cruise the MAP will get up in the 80s, and it helps with the economy to not have it run so rich in that row.

Name:  NA-AFRs.jpg
Views: 2010
Size:  50.2 KB
ScottFW is offline  
Old 10-08-2009, 10:52 AM
  #10  
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,659
Total Cats: 134
Default

Those "targets" you're showing us are for closed loop EGO correction. Are you running closed loop everywhere in that table?

If you're cruising at 85kPa, why are you so rich there?
__________________
Chief of Floor Sweeping, DIYAutoTune.com & AMP EFI
Crew Chief, Car Owner & Least Valuable Driver, HongNorrthRacing

91 Turbo | 10AE Turbo | 01 Track Rat | #323 Mazda Champcar

Originally Posted by concealer404
Buy an MSPNP Pro, you'll feel better.
Ben is offline  
Old 10-08-2009, 11:59 AM
  #11  
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

Originally Posted by hustler
Only they make more torque with more fuel, independant from spark adavance, lol.
can you explain "makes more torque" in the context of "not at WOT on an N/A car"?

because I thought making more torque was as easy as pushing your right foot a little further...
y8s is offline  
Old 10-08-2009, 12:38 PM
  #12  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

Originally Posted by gospeed81
To a certain point...and it starts to diminish around 13.0:1.

I can definitely see dipping below 14.0...I liked 13.8 when I was N/A.
Let the dyno do that talking. I made more torque at 11.5:1 than 12.0:1 at 200kpa.
hustler is offline  
Old 10-08-2009, 12:41 PM
  #13  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

Originally Posted by y8s
can you explain "makes more torque" in the context of "not at WOT on an N/A car"?

because I thought making more torque was as easy as pushing your right foot a little further...
i skipped over the 80kpa part.
hustler is offline  
Old 10-08-2009, 12:50 PM
  #14  
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

Originally Posted by hustler
i skipped over the 80kpa part.
that's cuz you live life at 200 kPa, paul walker.
y8s is offline  
Old 10-08-2009, 02:00 PM
  #15  
Elite Member
iTrader: (51)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Spring, TX
Posts: 7,257
Total Cats: 26
Default

Originally Posted by hustler
Let the dyno do that talking. I made more torque at 11.5:1 than 12.0:1 at 200kpa.
you made my point
gospeed81 is offline  
Old 10-08-2009, 02:06 PM
  #16  
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,659
Total Cats: 134
Default

Originally Posted by hustler
Let the dyno do that talking. I made more torque at 11.5:1 than 12.0:1 at 200kpa.
One day you'll understand that tuning efficient cruise and tuning for max power and both
-are entirely different concepts
-can be optimized on the same set of maps
__________________
Chief of Floor Sweeping, DIYAutoTune.com & AMP EFI
Crew Chief, Car Owner & Least Valuable Driver, HongNorrthRacing

91 Turbo | 10AE Turbo | 01 Track Rat | #323 Mazda Champcar

Originally Posted by concealer404
Buy an MSPNP Pro, you'll feel better.
Ben is offline  
Old 10-08-2009, 02:37 PM
  #17  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

Originally Posted by gospeed81
you made my point
I just stated this from experience. I suggest you put the car on the dyno and see what #'s it makes. It seems that quite a few think those #'s are set in stone.
hustler is offline  
Old 10-08-2009, 02:39 PM
  #18  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

Originally Posted by Ben
One day you'll understand that tuning efficient cruise and tuning for max power and both
-are entirely different concepts
-can be optimized on the same set of maps
Do you really want to do this again? I still affirm that retarding spark, with constant fuel, will not yield max fuel efficiency.

BTW, I scored 26mpg on the last tank. lol
hustler is offline  
Old 10-08-2009, 02:49 PM
  #19  
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,659
Total Cats: 134
Default

No, I don't. I never said that and you're obviously beyond help.
__________________
Chief of Floor Sweeping, DIYAutoTune.com & AMP EFI
Crew Chief, Car Owner & Least Valuable Driver, HongNorrthRacing

91 Turbo | 10AE Turbo | 01 Track Rat | #323 Mazda Champcar

Originally Posted by concealer404
Buy an MSPNP Pro, you'll feel better.
Ben is offline  
Old 10-08-2009, 02:52 PM
  #20  
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,085
Total Cats: 375
Default

Originally Posted by Ben
No, I don't. I never said that and you're obviously beyond help.
I argued that once achieving target AFR, run the max spark angle and it will maximize fuel efficiency. You're a Down's baby.
hustler is offline  


Quick Reply: N/A AFR targets (yes, again)



All times are GMT -4. The time now is 06:56 PM.