south_scoob

I have a blob recirc here and a forge vag diverter valve.. when pushing the piston up in the forge with finger covering the nipple the piston drops a little bit then stays up.
when you take your finger of the vacum nipple the piston dropps with a "tishh" (perfect working valve)

now on my impreza valve, for a start its verry hard to push the piston up (seems like verry stiff spring)!? also once its up with nipple closed the piston fully drops back down.
but then if i remove my finger from the nipple i still get a tishh of air.

not sure if this means the valves nakered or what. even with a baileys vta the piston stays up with the nipple covered untill you release it.

south_scoob

bump if anybody has ony lying about they dont mind testing.. just to make sure mines not leaking thanks

south_scoob

just wondering if anyone can shed some light on this? if the piston drops stright down does it meen the diaphrams torn or isit designed like this?

sovietspybob

iTrader: (3)

I'm sure the OEM recirc spring was a lot stiffer when i briefly had a Forge vta. The OEM one still seems to work fine though.

trevsjwood

iTrader: (2)

dumpvalves work on the equalisation/ differential of pressure either side of the throttlebody, so on full boost you have equal pressure through the intercooler and intake manifold, enabling the spring to keep the piston in place, as soon as the throttle is lifted throttlebody closes, pressure in the manifold drops but pressure in the intercooler, still high, pushes the piston open and releases the pressure to safeguard it feeding back to the turbo compressor wheel.
I have a turbosmart re-circ valve which has a soft spring, even at the hard setting it's easy to push the piston. The OEM one is much harder and difficult to move and I doubt you would keep it open by just sealing the nipple and not a sign it's knackered. A dump valve doesn't need a strong spring to be effective, the OEM one has a very thin sealing edge, wether or not this is the reason for the heavy spring.
I found the OEM became unreliable around 400hp and 1.5bar and essentially the only way to find out if there is a problem is to swop in a good quality re-circ and see if performance improves.
Trev