Does anyone know of a Dv that will hold over 2 bar without leaking,
Tried Baileys,Hks and Forge and all have leaked under pressure.
They were all second hand.

I hear turbosmart do some good ones??

You're welcome to try mine if you like for the mapping?

dont use one no boost leak

try a new one,ive seen all of the above at over 2 bar

here is a bailey that dealt with circa 2.5bar on a t4,515bhp 421 lb/ft and ran 180mph back in 2001 at bruntingthorpe (to put it in perspective,an r1 ran against it and could only get to 176mph!)
http://img.photobucket.com/albums/0703/MikeR/Sierra%20Photos/a4ad1bdf.jpg

I have a Turboxs which can run up to 35psi(2.4bar) boost.

I've run over 2 bar with my Forge DV006 and that's on the weakest spring.

Cheers guys,
Easy which make is yours.?

I have a stronger than standard spring for a forge (blue I think) let me know if you want to buy it for cheap.

The blue is aimed at 350bhp+ (as a rough guide)I think.

The Bailey valves are easily modified, if you strip them down and fit two washers to effectively act as shims it it increases the spring tension, common mod, the seals need to be in good nick though.

The spring rate really shouldn't come into it.

On boost, there is boost pressure on one side of the diaphram and boost pressure plus the spring pressure on the other side. So, unless there is a problem with the diaphram or it's sealing, or some problem with the a leak of boost pressure on the 'operating' side, all dump valves should be able to hold any boost pressure without leaking, as with everything working properly there is no pressure differential between either side of the diaphram.

but they do sell different rated springs because it is a common problem.

Exactly right - the pressure feed to the DV is into the side, NOT the bottom. As long as it's oriented this way, any amount of boost pressure should not be able to lift the piston off its seat

This is why the Coupe runs so much better with the softest spring - no boost leaks and it dumps excess pressure with the tiniest amount of vacuum

I have a good piece of testing equipment which utilises dry ice under pressure and nearly every coupe i have checked so far has had a leak above .7 bar initially and getting worse towards 1.5.
However the spring being too strong may cause chatter which can potentially stall the compressor wheel in extreme cases.
I was reading on another forum where they have removed the valve all together.