If a blowoff valve is installed in a car with stock turbo, will it make any noise?

Question

Im thinking about purchasing a 2000 Audi with stock Turbo. It already has a cool air intake. If I install a blowoff valve, will it make any noise or do I have to get a staged turbo kit to get any sound?

Answer 1

1. Your cold air intake is not doing anything for your car. A turbo car does not gain anything from a cold air intake, since the air is already as compressed as it can be, by the turbo. So, sorry, but that was a waste of money. You might have even lost power due to that.

2. If you already have a bypass valve on your car, you don't need another one. Especially if you have a stock turbo.

3. Since you refer to it as a blow off valve, I'll assume you want one that vents to the atmosphere. You do not need this.

4. A vent to atmosphere type blowoff valve will hurt your vehicle's performance, because it changes the amount of metered air that is registered by your ecu. In the long run, this can cause serious damage to your engine. Nevermind that it will also cause a loss of performance.

5. Never buy something just because of the sound.

Answer 2

There is already a blow off valve there. It is installed so that it discharges into the turbo system after the air meter and before the turbo. Which minimizes the blow off noise.

You may not like it, but any other way will cause problems when returning to idle, or shifting gears. Such as total engine shut down, impellers un-threading and decreases turbo lag under full acceleration.