GT Tuning 'Spider' Valve For use with our Pro-cockpit in-car adjustable boost control. It allows the user to accurately pre-set both minimum (below standard if required) and maximum boost ceilings, using two adjustable and lockable controls in the engine bay. This prevents accidental over-adjustment plus below standard boost for motorway, cruising etc; saving petrol, turbo and engine wear. Easy to fit & easy to adjust.Secondhand. Suitable for both the Phase I & II Renault 5 GT Turbo. Please email for more info.