kwhiteside
June 30th, 2009, 02:21 AM
My Actual AFR is running richer than commanded during serious track days and I'm trying to figure out my tune.
The EFILive guys gave me a list of things to check, starting with the B4001 Injector Flow Rate table.
I've researched like crazy about Injectors and have some understanding now.
Stock Z06 Injectors are rated at 28lb for 58psi 4bar. The spreadsheet defaults to 43.5psi 3bar because that is how most injectors are rated when sold.
So if I input a flow rate of 28 at a rated rate of 58, but then change my actual pressure to 68 which it is, I start seeing problems. This is assuming my injectors are still stock. ( I now know there should be a part number on the side of them, I'll get that when I get my glasses to read ) So I'm racing around and my commanded AFR is based on a 58psi table when actually I'm pushing out 68psi and more fuel. This explains why I'm running richer than commanded. Now if my injectors are upgraded bigger ones, that condition would be even worse to the rich side. The pcm is sending voltage to the injectors like they are small 28lb injectors at 58psi, but if they are big 40lb injectors being hit with 68psi, they will be releasing too much fuel.
Please confirm what I'm thinking that if this IFR table is too low, I'll be running richer than commanded?
Also please explain why the b4001 table and the injector.xls spreadsheet stop at map Kpa stops at 80. When I'm speeding along, my map gets close to 100 Kpa which is off the table? Is there another place for WOT IFR?
I'm learning as fast as I can, don't laugh too hard at that last question. I hear guys talking about how the WOT settings are less computer controlled all the time, I just don't know where to look inside EFILive yet.
The EFILive guys gave me a list of things to check, starting with the B4001 Injector Flow Rate table.
I've researched like crazy about Injectors and have some understanding now.
Stock Z06 Injectors are rated at 28lb for 58psi 4bar. The spreadsheet defaults to 43.5psi 3bar because that is how most injectors are rated when sold.
So if I input a flow rate of 28 at a rated rate of 58, but then change my actual pressure to 68 which it is, I start seeing problems. This is assuming my injectors are still stock. ( I now know there should be a part number on the side of them, I'll get that when I get my glasses to read ) So I'm racing around and my commanded AFR is based on a 58psi table when actually I'm pushing out 68psi and more fuel. This explains why I'm running richer than commanded. Now if my injectors are upgraded bigger ones, that condition would be even worse to the rich side. The pcm is sending voltage to the injectors like they are small 28lb injectors at 58psi, but if they are big 40lb injectors being hit with 68psi, they will be releasing too much fuel.
Please confirm what I'm thinking that if this IFR table is too low, I'll be running richer than commanded?
Also please explain why the b4001 table and the injector.xls spreadsheet stop at map Kpa stops at 80. When I'm speeding along, my map gets close to 100 Kpa which is off the table? Is there another place for WOT IFR?
I'm learning as fast as I can, don't laugh too hard at that last question. I hear guys talking about how the WOT settings are less computer controlled all the time, I just don't know where to look inside EFILive yet.