A Tuning Performance Question !?

[sweet97]

Iam running a 50 trim on 550cc inj's. 710cc's will be ordered tomorrow. I can ease to 13 psi no knock at all. Hit WOT and lots of knock but with similar a/f ratios.
The 550's are maxed at 13 psi but i have pushed them to 15 a few times. What is causing the knock at WOT when I have the same A/F? I was set with an EVO but got a great deal on an AGP 50 I couldn't pass up. I have a street FMIC from Dejon that is working well. Hot AT THE INLET AND cold on the output. I could probably run 15 psi if i eased into it! Thanks, Mark

 

[1LE]

Iam running a 50 trim on 550cc inj's. 710cc's will be ordered tomorrow. I can ease to 13 psi no knock at all. Hit WOT and lots of knock but with similar a/f ratios.
The 550's are maxed at 13 psi but i have pushed them to 15 a few times. What is causing the knock at WOT when I have the same A/F? I was set with an EVO but got a great deal on an AGP 50 I couldn't pass up. I have a street FMIC from Dejon that is working well. Hot AT THE INLET AND cold on the output. I could probably run 15 psi if i eased into it! Thanks, Mark

What exactly is the A/F you're seeing?

 

[sweet97]

Most often a 11.0-11.5:1 a/F ratio. I know the injectors are maxed at 13 psi and if I do a partial throttle approach I am without knock. Hit WOT and lots of knock. I ordered the 710's today. I just don't understand why I don't get a lean condition when I push it hard and it goes to 15-16 PSI.????Mark

 

[1LE]

What did you run on the Evo (psi, and A/F)?

 

[sweet97]

18 PSI on the EVO with a 10.5-11 a/f if I recall correctly due to the stock sidemount.I now have the dejon street FMIC. 710cc's on order. I just don't understand why I do not read lean when I am pushing the 550's. I hope to get to 18 PSI with the bigger injectors. I'll be getting a AFPR when they are in stock. I have a Walbro/255 never instaled because I never ran lean. Volume is the true barameter of a fuel pump, maybe that's my problem. Mark