AFR revisited
06-20-2004 | 09:35 PM
#1
Thread Starter
Rennlist Member
Joined: Jul 2002
Posts: 77,321
Likes: 668
AFR revisited
For those that reviewed and replied to my thread about my low AFR and power loss, thank you.
Now to add to the mix:
Today I pulled all lines after the turbo to inpect them and make sure they were good and tight. All hoses are intact with no crack or breaks. I was meticulous with the reinstall and am certain all are tight. I even replaced all my old vacuum lines.
This afternoon, when I went on a test drive, I am still peaking at 12psi with a slow bleed off to ~9psi by redline. I haven't put it on a dyno to verify AFR but I have a feeling the culprit is not a vacuum leak.
Is there anywhere else I can look? Is there really a way the wastegate can affect AFR? Personally, I think a wastegate will allow me to make more boost and hold it longer putting to use the rich condition.
I plan to revisit the other dyno shop to eliminate differences in dynos.
Now to add to the mix:
Today I pulled all lines after the turbo to inpect them and make sure they were good and tight. All hoses are intact with no crack or breaks. I was meticulous with the reinstall and am certain all are tight. I even replaced all my old vacuum lines.
This afternoon, when I went on a test drive, I am still peaking at 12psi with a slow bleed off to ~9psi by redline. I haven't put it on a dyno to verify AFR but I have a feeling the culprit is not a vacuum leak.
Is there anywhere else I can look? Is there really a way the wastegate can affect AFR? Personally, I think a wastegate will allow me to make more boost and hold it longer putting to use the rich condition.
I plan to revisit the other dyno shop to eliminate differences in dynos.
06-21-2004 | 06:07 AM
#2
Race Director
Joined: Jul 2001
Posts: 14,075
Likes: 3
From: Santa Barbara, CA
" Is there really a way the wastegate can affect AFR?"
yes, since full-throttle WOT fuel is a fixed pre-programmed value, if you change the assumed airflow, it will change the air-fuel ratio as a result. Since the chips were programmed for more flow than you're getting, you'll end up too rich. I'm betting it's the wastegate.
yes, since full-throttle WOT fuel is a fixed pre-programmed value, if you change the assumed airflow, it will change the air-fuel ratio as a result. Since the chips were programmed for more flow than you're getting, you'll end up too rich. I'm betting it's the wastegate.