TRANSITIONAL KNOCK SPIKE AT 3800 RPM

[quadzila]

TRANSITIONAL KNOCK SPIKE AT 3700 RPM

I have an annoying knock spike that sets off my audible knock sensor that im trying to fix and looking for some help please. It seems to always happen at 3600-3800 rpm 7-8 psi boost spike to 4* then go away. I ease into ½ throttle as boost and rpm picks up it hits. Exhaust is tight not hitting. Any input to help will be greatly appreciated….thanks

 

[turbofabricator]

Look at your timing tables in that RPM range. Pull a few degrees of timing out. Start there. With XFI it should be a snap to tweak the timing table or fix the fuel curve. What does the WB O2 read at that point in the game?

 

[quadzila]

Look at your timing tables in that RPM range. Pull a few degrees of timing out. Start there. With XFI it should be a snap to tweak the timing table or fix the fuel curve. What does the WB O2 read at that point in the game?

rite before the knock spikes its at 13.75 a/f and the timing is at 28*