Personally, I wouldn't try any of this stuff without a datalogger. You guys have no idea if your engine is knocking or not.

Knock is a cumulative thing. You may not have any problems immediately, but a year down the road, you may blow your headgasket, bend a rod, crack a piston, etc...

Incidentally, when I run race gas (117 octane leaded), I run 24psi through my 16G turbo, and get zero knock.

When I run 18psi on 93 octane, I get minimal knock.

And I know this because I have datalogged my car with those settings.

 

Would there be any benefit from running just a boost controller without any other mods, holding 19psi up to redline? Would the already rich fuel/air mix support it without anything going wrong?

I want to start mods, and I'm thinking about going with a boost controller first.

 

Your first mod should ALWAYS be a boost gauge.