Bypass valve

a.k.a. "BPV" or "DV" (Diverter Valve)

Valve which relieves charge pressure by venting air back into the ambient pressure intake tract.

Prevents turbo surge but preserves LTFTs, since measured air will still eventually enter the combustion chamber.

All street cars that use MAFs upstream of a charge pressure relief system should use BPVs rather than blow off valves.

Variants: (work in progress, part numbers needed, should reformat into table)

• 710 original (OEM for all S4s, <2000 A4/TT/Passat)
• 710A 8.8lb spring (OEM for <2002 A4/TT/Passat)
• 710B (OEM for S2?)
• 710C (OEM for Beetle?)
• 710G (14lb spring? some came in bags labled N?)
• 710H ?
• 710N 14lb spring (OEM for 2002 A4/TT)
• 710P (OEM for RS6). Has a reinforced silicone diaphragm, and has brass guides holding the sealing lip in alignment with the seat. The valve begins to open at ~ 6 in-HG vacuum.

possible part numbers(?):

• 06B-145-710 S4 2.7
• 034-145-710A/B/C/N A4 1.8t, S2, Passat, Beetle
• 06A-145-710A/H/G/N/P TT 1.8t, RS6 4.2t