How do I choose the right spring rating?
- Choose the spring by the engine's idle vacuum, not by boost. Measure idle vacuum with a reliable gauge and compare it with the spring chart for the valve. Supercharged engines use a very weak spring so the valve stays open at idle, which is normal for those setups.
Does the Q need a new flange welded in?
- No welding is needed when a standard TiAL BV50 flange is already in place; the Q bolts straight to it. A weld flange, clamp assembly and O-ring are included for a new installation.
How loud is the Q compared with the QR?
- The Q's open body gives the greatest flow and a quieter discharge. The QR discharges at higher velocity with less flow, so it is typically louder when it is not recirculated.
How should the vacuum line be connected?
- Run 1/4 in (6 mm) hose from the air fitting to full engine vacuum, preferably directly at the intake manifold, with no check valve or tee in the line.
What warranty does it carry?
- TiAL Sport covers its products for 24 months from the date of purchase against defects in workmanship or components. Mishandling, abuse or faulty installation void the coverage, and the warranty is not transferable.