Ok pal. I'm not really suggesting the boost gauge for tuning, just so you have some certain figures to look at. Being standard pressure being around 13~psi and if you stick one on now and you find its boosting like 7psi, you know you could be looking at a boost leak. Or, you fix your 'jet noise' and you find it's boosting 18psi, then you know the fuel/turbo has been altered. Just easier for troubleshooting.
PH1 306 XUD - 11mm VE, Big 'bine, TMIC = Plenty of coal, abuse, heatsoak and a power band of 4.3k - 6k = One shagged car.