FINALLY cured my compressor surge!!!!
 

At last after trying loads and loads of things its finally gone,and it all points at the VF35!!,did not want to change the vf35 but now have fitted an MD304 (VF22 hybrid),along with ditching the vta d/v and fitting an oe sti recirc d/v,also swapped the standard 2 port to a 3 port and all is sweet its the smoothest its ever been i cant even make it surge at all now,and im still running the samco inlet hose;) ,well happy,just need the map tweak now see you soon paul:)

Very interested in this news as you're not the only one who's had surge problems with a VF35. Mine was OK on a standard v4 STi TMIC but as soon as I fitted an FMIC, it was surging terribly, on a silicone pipe as well which had previously been OK. I also changed back from a Forge recirculating DV to a standard OE DV and this made a noticeable difference as well.

I changed to a TD05-16G in the end, which still surges a little but nothing like the VF35 did.

Why does the standard DV cure the problem? What is so different about the standard DV compared to others, the Forge for example, is it it's spring rate?

It just did. The standard DV stays shut until it actually needs to dump. I think others either partially open at lower boost levels or don't have the through-flow required. Basically the standard DV is a monster.

Can't remember ever seeing any of the top tuners on here recommending anything other than a standard dump valve for us normal folk.

H4rdy-P1, does the MD turbo still have the p20 housing? Just wondering.

I have tried 6 different type of BOVs without any success. HKS I, HKS II, Blitz, Turbo XS RFL, Tial, Forge....

OEM Dump valve is the way to go but at high boost pressure it may leak.

No it uses the p18 exhaust housing,ported out to 50mm on the exhaust uppipe side,feels very strong compared to the vf35 and sounds sweet too,just a little laggye'r than the 35.