Sorry, I'm VERY late to this thread, but you caught my interest here. I'm finding that if I remotely get close to 10psi with my "mostly Safari" setup, it ping like a MOFU on premium. I have 170k on the clock and seems to be solid motor. It had a Unichip for years before I put a wideband on it and discovered that it was running STUPIDLY lean, to the point that it cracked my manifold. (My saga
HERE.) So after that $3,500+ learning curve... it's all stock fuel management with a K&N filter.
Do you have something going on for fuel management? I am bringing the old girl out of the garage and might hit the dunes this year and would love to get it up to 10PSI safely if that is realistic.
PS - For those asking why turbo vs SC? It's hard to explain why turbo is SOOO much better. I've had 2 SC'd 4Runners, and my turbo'd 80. The power band of the 80 for all wheeling, especially sand is incredible. (Granted bigger base motor than the 3.4.)
If anyone is in Spokane WA they are welcome to take it for a spin to see the difference.