HI, I enjoy reading all of your post. I just dynoed my 73 240zt for the first time and got 203hp and 262 tq. My boost level falls just like what you have experienced. What was your fix?????
I have a very similar setup like yours ie, stock engine ,14psi,supra ic, diy mbc, stock f.pump, injectors,300zxt ecu and maf. I do not have a rrfpr. Thanks for any help,Kenny(L.A)