i have a greddy 15g kit on my d16z6. im going to up the boost on it soon so the first step was to install the plx m300 wideband. its on the stock 5.5psi right now using the e-manage that came pretuned with the kit. everyone has always said it is tuned rich and they were right. it reads about 10.8-11 throughout boost. sometimes lower at partial throttle.

is 12:1 really that safe or should i tune it for about 11.5?

 

Tune it for 11.5...the power difference between 11.5:1 and 12:1 is not a big change. Better to be safe incase you get a bad batch of gas or something.