You can expect an increase of 3 to 4PSI (peak boost) but the real improvement is in the mid-range

now featuring a billet aluminium housing and bullet valve technology for ultra fast boost response with two adjustable boost levels

Brown/Black 3psi Inner Spring

If the steering rack is changed it has to be mounted exactly where the OEM steering rack was

upgraded camber arm and reinforced knuckle

Vesser VSR4 20x9 ET20-51 5H BLANK Custom Finish Ceramic coating You can expect an increasePCD: 5x108, 5x110, 5x112, 5x114. 3, 5x115, 5x118, 5x120, 5x120. 6, 5x127, 5x130 ET: 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51