Optimal A/F ratio for NA
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
As far as which side to install the pre-cat bung while using a data-logger and wideband--
Depends on what you want see or use as a base---Indudtry standard is to read the Wideband voltages and AFR on the LEANEST side of the engine so while making changes you are always erring on the side of rich Reason being because of the New GM firing order the 2 cyllinders that fire one after the other now are now on the Passenger Side rather than as before on driver's side ---Whatever side has 2 cylinders firing one after the other you will always have a leaner AFR on that bank because of the heat--
Depends on what you want see or use as a base---Indudtry standard is to read the Wideband voltages and AFR on the LEANEST side of the engine so while making changes you are always erring on the side of rich Reason being because of the New GM firing order the 2 cyllinders that fire one after the other now are now on the Passenger Side rather than as before on driver's side ---Whatever side has 2 cylinders firing one after the other you will always have a leaner AFR on that bank because of the heat--
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
The July 12 release from EFILIVE added the "Max Brake TQ timing table " which sets the MAX timing amount allowed by the ECM to use to try and achieve the Commanded TQ from the TQ response tables
It's actually a very simple system but a complete new way of tuning and you have to re-think what you're doing while making changes--I have tuned 12 DI s=Silverados and 5 C7's all with this new procedure and it works beyond any owners expectations
YES they are still missing some tables mainly the fans and any tables to correct AFR with LT's or serious mods like heads / cam They started by accommodating the basic CAI and exhaust mods and are working to advance to internal mods---In their defence--Not many cams and such are yet available for a VVT /DOD and DI engines yet
But as time goes by They will have all the necessary table to accommodate any Mods---
Talk to Jesse Bubb -at Wait4meperformnce---He will tell you the exact same things !!!
Last edited by tblu92; Jul 23, 2014 at 04:24 AM.
Thread Starter
Instructor
Joined: Jan 2001
Posts: 169
Likes: 0
From: Rock Hill SC
Good info. I don't have the complexity of EFIlive or HPTuners. I'm only using Diablosport IN-Tune with custom tuning. So all I can change is PE fuel%.
I installed the WB. From 4k rpm and up, WOT was 11.9:1. From 2K to 4K looked to be about 12.8:1.
I made one adjustment and got the top end up to 12.2:1. Will go back and take out some more fuel on top WOT.
I did notice my cruise A/F was about 14.7 - 15.0
I installed the WB. From 4k rpm and up, WOT was 11.9:1. From 2K to 4K looked to be about 12.8:1.
I made one adjustment and got the top end up to 12.2:1. Will go back and take out some more fuel on top WOT.
I did notice my cruise A/F was about 14.7 - 15.0
Race Director
Joined: Jul 2007
Posts: 10,959
Likes: 2,641
From: Texas Hill Country
What are you trying to say is incorrect ?? You consistently want to argue with me about the technical tables regarding tuning a C7--I do realize the Diablo and HP use different table names as compared to EFILIVE---But EFILIVE still has more adjustability in their software than anyone else---All my statements are made from real world trial and error tuning to see how the E92 ECM works---Yes It is a fact the new closed loop AFR is 14.11---So why would you want to alter that ? So when data logging the P/T fuel you would try to achieve 14.11 because that's the AFR that the fuel trims and 02's are correcting to !!!If you change any of that you open up so many areas for trouble
The July 12 release from EFILIVE added the "Max Brake TQ timing table " which sets the MAX timing amount allowed by the ECM to use to try and achieve the Commanded TQ from the TQ response tables
It's actually a very simple system but a complete new way of tuning and you have to re-think what you're doing while making changes--I have tuned 12 DI s=Silverados and 5 C7's all with this new procedure and it works beyond any owners expectations
YES they are still missing some tables mainly the fans and any tables to correct AFR with LT's or serious mods like heads / cam They started by accommodating the basic CAI and exhaust mods and are working to advance to internal mods---In their defence--Not many cams and such are yet available for a VVT /DOD and DI engines yet
But as time goes by They will have all the necessary table to accommodate any Mods---
Talk to Jesse Bubb -at Wait4meperformnce---He will tell you the exact same things !!!
The July 12 release from EFILIVE added the "Max Brake TQ timing table " which sets the MAX timing amount allowed by the ECM to use to try and achieve the Commanded TQ from the TQ response tables
It's actually a very simple system but a complete new way of tuning and you have to re-think what you're doing while making changes--I have tuned 12 DI s=Silverados and 5 C7's all with this new procedure and it works beyond any owners expectations
YES they are still missing some tables mainly the fans and any tables to correct AFR with LT's or serious mods like heads / cam They started by accommodating the basic CAI and exhaust mods and are working to advance to internal mods---In their defence--Not many cams and such are yet available for a VVT /DOD and DI engines yet
But as time goes by They will have all the necessary table to accommodate any Mods---
Talk to Jesse Bubb -at Wait4meperformnce---He will tell you the exact same things !!!
also, you are wrong about its function.....you and bubba have fun tuning.
Instructor
Joined: Jul 2014
Posts: 131
Likes: 17
