Hi. The 13g is a Mitsubishi TD04HL-used in the FWD Volvos (850's - not the t-5's or R's, maybe the s70...not sure about that one). It is a low pressure turbo. Some people do configure them for use in the RWD's, but they are obviously not as popular as the larger Mitsu's or the Garretts. As for the max boost, I believe it's capable of somewhere around 12 psi with the use of an MBC. What car are you thinking of using it for?