BOV's/DV's - Do you REALLY need one? - 8th Sep 2005 8:55am
On a different board im in there's been quite a large discussion on the necessity of blow off valves and dump valves. I've heard before that you need them to prolong turbo life etc, but if thats the case then why dont cars come with them as standard? Some come with recirculationg ones but is that just to keep the noise of the turbo (wastegate flutter/chatter/whatever) down ?
So basically, will it harm your car by not using a BOV or DV?
Quote
Originally posted by Some Guy:
The word 'Wastegate flutter' is often mis-interpreted for the actual wastegate opening and closing which it is not.
The correct term is compressor stall - but even that is slightly incorrect. As you take your foot off the accelerator the throttle body closes, the turbo is still spinning causing a build up of compressed air. This is why your hoses are made from silicone too, because they can expand. As the air compresses it'll force it back through the way it came and over the turbo compressor, it doesn't stall the compressor - just slows it down as it passes over it. It chops the air which is the flutter you hear.
Most cars owners put a dump valve just before the TB after the intercooler, which is a complete WASTE of cold/intercooled which is ready to go straight into the plum chamber if you change gear quick enough.
Dump valves are just a gimmic, they don't offer and performance increase. And more than often can cause problems by leaking etc etc. The only real reason you'd fit a dump valve is to help prevent strain on the turbo seals, but the difference in turbo life will be next to nothing. Its more customer satisfaction, and precaution for cars that come pre-installed.
Like what was said above you don't hear any rally cars with a dump valve do you.
The word 'Wastegate flutter' is often mis-interpreted for the actual wastegate opening and closing which it is not.
The correct term is compressor stall - but even that is slightly incorrect. As you take your foot off the accelerator the throttle body closes, the turbo is still spinning causing a build up of compressed air. This is why your hoses are made from silicone too, because they can expand. As the air compresses it'll force it back through the way it came and over the turbo compressor, it doesn't stall the compressor - just slows it down as it passes over it. It chops the air which is the flutter you hear.
Most cars owners put a dump valve just before the TB after the intercooler, which is a complete WASTE of cold/intercooled which is ready to go straight into the plum chamber if you change gear quick enough.
Dump valves are just a gimmic, they don't offer and performance increase. And more than often can cause problems by leaking etc etc. The only real reason you'd fit a dump valve is to help prevent strain on the turbo seals, but the difference in turbo life will be next to nothing. Its more customer satisfaction, and precaution for cars that come pre-installed.
Like what was said above you don't hear any rally cars with a dump valve do you.