power fc a/f ratio and knock

[VATOCLOWN]

ok i got a strange one this time i did a pull last night to 7500 rpm and noticed that my a/f was good up till about 6500 prm then it started leaning out my knock was at 20-22 at most. now i like my af to 11.8-12.1 on pump gas no higher than 15psi. last night after 6500 prm my af went from 12.0 to 13.0 and by redline it was at 14.0 but my knock was still 20-22. so i fixed the a/f ratio and my knock shot up from 20-22 to 38-40 wtf. can anyone give me any insight.

this is on an sr20det redtop the bottom is forged with cp pistons,manley rods and acl bearings. the head is done too with a 5 angle valve job dual inner and outer springs and 264 cams. the turbo is a t3 50trim and i use the power fc. so if someone can tell me why my knock is higher when the a/f is considered safe and my knock is lower when a/f is considered unsafe for boost.

[steve shadows]

ok i got a strange one this time i did a pull last night to 7500 rpm and noticed that my a/f was good up till about 6500 prm then it started leaning out my knock was at 20-22 at most. now i like my af to 11.8-12.1 on pump gas no higher than 15psi. last night after 6500 prm my af went from 12.0 to 13.0 and by redline it was at 14.0 but my knock was still 20-22. so i fixed the a/f ratio and my knock shot up from 20-22 to 38-40 wtf. can anyone give me any insight.

this is on an sr20det redtop the bottom is forged with cp pistons,manley rods and acl bearings. the head is done too with a 5 angle valve job dual inner and outer springs and 264 cams. the turbo is a t3 50trim and i use the power fc. so if someone can tell me why my knock is higher when the a/f is considered safe and my knock is lower when a/f is considered unsafe for boost.

It sounds like your fuel pump may be going out, this also happens if the fuel level is low or your fuel gauge is bad and you don't actually have fuel in the tank, also fuel pressure if it's really really clogged could cause this or a big failure of the fuel pressure regulator. There is also an issue with the stock fuel pump circuit common with Walbros where this happens in the higher rpms, but it varies from car to car, I would check the fuel filter on the pump and make sure the pump is ok and also fuel system in general. If it worked fine before and just started doing it that's probably your culprit.