Chuck you are seeing 25psi? If so you are running 91/93as well. Just my guess here, but if you are running 25 psi that puts the Cr at what around 23.5? Seems withthat much boost you must run racing fuel. I would not think there is enough timing adjust to make it not knock? You at a very high elevation?
At that other site, i read once a simular issue and did not they come to find out there issue was time chain guide was wore out. <just something i remember reading.
Is that "race" tune set for 91 and 25psi? The term race and street gas just dont make sense to me, if its a "race" seems you need raceFuel.
I have the solo cat and mach shorty Gm tune, stock air and IC. I tunned the waste gate as well(i think that put me in the knock zone). I was getting the knock, i am at 300ft in the heat of hell summer time 115-125 i see 20-23psi, winter i see 18-20. I put a full tank of sunoco 100uleaded just to see if that worked, like a charm car pulls like a bat out of hell(i also unpluged the battery when i did this to get a fresh start. Then i started backing off the 100 to 50/50 no pingknock, even went down to 25/75 no ping but less power. I tried all those BS octain boosters waist of money. i run 50/50 now all the time runs like a top. but we have these pumps with sunoco and other brands all over town here, just cost like you are in the EU.
If i had a "racetune" i think it would need at least 100unleaded, just my guess.
Have you tried some 100+octain fuel, I would and see if that does it