Bad Engine Knock (S13 Blacktop)

[freakyjason]

Okay, I am seriously at my whits end with this. First, a little about my setup:
S13 blacktop SR20det
JWT tuned ECU (Z32 maf, MSD 72 lb injectors[with 6.8 ohm resistors soldered in], 91 octane, 22lbs of boost)
JWT S3 cams
JGY topmount fuel rail
Tomei adjustable fuel pressure regulator
Walboro 255lph fule pum
Front mount intercooler
etc. etc.

So my problem is as follows: My car has begun to knock at around 15psi of boost at wide open throttle. My air fuel ratio used to be fine (between 10.7 and 11.5) until JWT told me to lower my fuel pressure to 43.5psi. Now the air fuel is at 13.2 at WOT. I've checked the mechanical timing NUMEROUS times and it is spot on. With a timing gun it reads 15 degrees at idle. The oil pressure is good as well (about 23 at idle, 50+ when cruising on the highway). I've replaced the Maf, the knock sensor (twice), the coolant temp sensor, the CAS, the tps sensor (and made sure it was within the proper operating voltage range), and the fuel pump. I don't know where else to turn or what else to check. I've been looking into the Blazt for datalogging which I can then send to JWT but my car is a '90 so I don't have the diagnostic port for it. Any input would be GREATLY appreciated!!!

[Lobo240sx]

Try lowering the boost first and see what happens. If the knock goes away you need more octane to run more boost 93 or race gas if you have it.

[freakyjason]

The Knock only comes on at around 15lbs of boost. The car has 93 Octane in it. This is a recent development over the past few months I've used the same gas at 20 psi no problem before.

[freakyjason]

Bump? Any other ideas?

[freakyjason]

I have discovered via the remarkable capabilities of the blaZt consult system that it was the timing map in the JWT tune. The tune is good, just needs to be fine tunned for my particular application.