A blow-off valve is mounted in the engine exhaust system and has various functions. When the engine throttle is closed, high pressure occurs due to the airflow/speed from the turbocharger. To keep the airflow going and not set in motion pressure waves, it makes the blow-off valve vent. This also means that the turbocharger's revolutions are kept going and you thus maintain better charging pressure between gear changes.
Inside the blow-off valve, a spring is mounted, which often keeps the valve closed up to approx. 0.6 bar charge pressure, but when you add pressure/vacuum which is in the intake manifold, the blow-off valve will open up when the car is idling with vacuum and keep the valve closed with charge pressure, as the charge pressure presses down on the piston. When you go from the full throttle and charge air pressure to closed throttle, the turbocharger is still in full swing, large vacuum in the manifold which opens the blow-off valve so that the overpressure can escape into the open air or recirculate. This keeps the turbo's revs up and is ready for the next gear.
Qualitec.eu sells several different types of cheap blow-off valves. A blow-off valve is used in connection with "venting" of the high overpressure that comes from the turbo when closing the throttle. Buy blow off valves online, we ship daily on all valves that are in stock.
In order not to damage the turbo, it is important to have a blow-off valve fitted. Buy blow off valves on this page at cheap prices.
Most of our blow-off valves are universal. If we do not have one for your model, you can send us an email with pictures of your original valve with dimensions on the nozzles, etc. so we can find one that fits your model.