hi people,
i recently boosted my car to 12 psi and i have 2 probs 1 of these is i've boosted it to 12 psi but on my stock boost gauge its hitting +7 hmg which is equivelant to 14.6 psi and 2nd prob is everytime i hit max boost im getting backpressure anyideas why this maybe happening? thanks for takin time to read and help much appreciated.