Notices
Vishnu Performance - California [Visit Site]

Does ECU pull timing with A/Fs higher than 11.5?

 
Thread Tools
 
Search this Thread
 
Old Dec 8, 2004 | 08:35 AM
  #1  
Jorge T's Avatar
Thread Starter
Evolved Member
iTrader: (18)
 
Joined: May 2004
Posts: 1,494
Likes: 1
From: Houston, TX
Does ECU pull timing with A/Fs higher than 11.5?

Fact or Fiction? Does Xedeflash correct for this?
Old Dec 8, 2004 | 10:41 AM
  #2  
4-BNGR's Avatar
Evolved Member
iTrader: (3)
 
Joined: Jul 2003
Posts: 1,768
Likes: 1
From: Charlotte, NC
Higher than 11.7
Old Dec 8, 2004 | 02:28 PM
  #3  
Jorge T's Avatar
Thread Starter
Evolved Member
iTrader: (18)
 
Joined: May 2004
Posts: 1,494
Likes: 1
From: Houston, TX
So we can't race tune on 104 oct at 12.5?
Old Dec 9, 2004 | 06:45 AM
  #4  
Jorge T's Avatar
Thread Starter
Evolved Member
iTrader: (18)
 
Joined: May 2004
Posts: 1,494
Likes: 1
From: Houston, TX
I ask this since the difference between 93 and 104 files on my GTI was close to 40-50whp. 93 ran A/F 11.0 -11.5 and 10-12 deg advance timing at top. 104 ran A/F 12-12.5 and 20-22 deg advance at top.... just curious as why the difference
Old Dec 9, 2004 | 06:48 AM
  #5  
shiv@vishnu's Avatar
Evolved Member
iTrader: (20)
 
Joined: Mar 2003
Posts: 4,941
Likes: 0
From: Danville/Blackhawk, California
Originally Posted by Jorge T
Fact or Fiction? Does Xedeflash correct for this?
Not sure what you're asking.

shiv
Old Dec 9, 2004 | 07:07 AM
  #6  
Jorge T's Avatar
Thread Starter
Evolved Member
iTrader: (18)
 
Joined: May 2004
Posts: 1,494
Likes: 1
From: Houston, TX
I saw someone post ( a tuner) that the ECU pulls timing if it sees A/F higher than 11.5:1 and ws curious about how true the statement was.
Old Dec 9, 2004 | 07:33 AM
  #7  
Ludikraut's Avatar
Evolved Member
iTrader: (17)
 
Joined: Apr 2004
Posts: 6,224
Likes: 0
From: 41° 59' N, 87° 54' W
How can the ECU determine A/F when it doesn't have a wideband O2 sensor to work with?

AFAIK the stock setup only has a narrowband O2 sensor and that can only show the difference between stoich and non-stoich readings. I'm certainly no expert on this, but as far as I've seen/read the ECU will only pull timing based on predictive analysis and engine knock sensor activity, no?

l8r)
Old Dec 9, 2004 | 07:41 AM
  #8  
Jorge T's Avatar
Thread Starter
Evolved Member
iTrader: (18)
 
Joined: May 2004
Posts: 1,494
Likes: 1
From: Houston, TX
That's what I thought...
Old Dec 9, 2004 | 04:34 PM
  #9  
A418t81's Avatar
Evolved Member
iTrader: (5)
 
Joined: Nov 2003
Posts: 849
Likes: 0
From: Birmingham, Al
I miss the logging and blocks of the ME 7.X. It was a draconian beast when it came to getting the thing to do exactly what you wanted it to consistantly, but it definitely was the bomb as far as information output. I would love some cylinder specific timing retard and boost blocks among other things for the Evo
Old Dec 9, 2004 | 04:41 PM
  #10  
propellerhead's Avatar
Evolved Member
iTrader: (3)
 
Joined: Sep 2003
Posts: 1,394
Likes: 0
From: Agrestic
WOT = open loop mode. The lambda sensor is ignored in open loop mode.
Old Dec 9, 2004 | 07:25 PM
  #11  
Jorge T's Avatar
Thread Starter
Evolved Member
iTrader: (18)
 
Joined: May 2004
Posts: 1,494
Likes: 1
From: Houston, TX
My Q stems from 4th paragraph https://www.evolutionm.net/forums/sh...8&postcount=42
Old Dec 9, 2004 | 07:33 PM
  #12  
MYEVOVIII's Avatar
Evolved Member
iTrader: (35)
 
Joined: Mar 2003
Posts: 1,983
Likes: 0
From: Atl/Southeast
Originally Posted by Ludikraut
How can the ECU determine A/F when it doesn't have a wideband O2 sensor to work with?

AFAIK the stock setup only has a narrowband O2 sensor and that can only show the difference between stoich and non-stoich readings. I'm certainly no expert on this, but as far as I've seen/read the ECU will only pull timing based on predictive analysis and engine knock sensor activity, no?

l8r)
This is what I have heard as well.
I have seen cars with higher A/F ratios on pump but it is not recommended the max from others have told me is about 11.6 you could go higher but run the risk of being too lean and having Detonation/Knock. And you can go leaner if you have higher octane I have seen some Xede race maps with 12's for A/F. But I am no tuner this is just what I have seen a different dyno days.
Old Dec 9, 2004 | 07:37 PM
  #13  
propellerhead's Avatar
Evolved Member
iTrader: (3)
 
Joined: Sep 2003
Posts: 1,394
Likes: 0
From: Agrestic
I * think * Al's saying that the engine becomes knock prone at AFRs of 11.5 and greater. As a result of the knock the ECU pulls timing. You could be running 24 psi of boost at 11:1 and probably have the ECU pull timing.
Old Dec 9, 2004 | 07:46 PM
  #14  
Jorge T's Avatar
Thread Starter
Evolved Member
iTrader: (18)
 
Joined: May 2004
Posts: 1,494
Likes: 1
From: Houston, TX
That makes more sense...it just was not clear
Old Dec 10, 2004 | 07:32 AM
  #15  
Ludikraut's Avatar
Evolved Member
iTrader: (17)
 
Joined: Apr 2004
Posts: 6,224
Likes: 0
From: 41° 59' N, 87° 54' W
Originally Posted by propellerhead
I * think * Al's saying that the engine becomes knock prone at AFRs of 11.5 and greater. As a result of the knock the ECU pulls timing. You could be running 24 psi of boost at 11:1 and probably have the ECU pull timing.
... wow, that's being pretty kind ...

l8r)
 




All times are GMT -7. The time now is 06:00 AM.