I fitted a forge dump valve to my 97 wrx ver 3, I made a make do bung but when i checked it when i got home I could see it was about to give way. I was wondering what bung size i need as interior measurment on the little bit of blue tubing I have is 25mm across. I have been told i would need 35mm bung but surely if it measures 25mm on the inside then I would need a 25 mm bung. Some 1 please help as cars off the road till i get 1!

 

What are you trying to Bung? When I blocked my dump valve off I turned some 34mm Bungs and they were spot on?????

 

where the original re circ would have gone i made a bung but it was about to pop off by the time i got home just not sure what size bung to get surely if the diameeter in the tubing i have is 25mm then something bigger like 34-35 would be better wouldnt it? this is what im not sure of

 

Whatever the recirc port hole's I.D. measures, then you need to make sure the bung's collar that fit's inside the hole is about 0.5mm/1mm bigger for a nice, snug interference fit. I'd also supplement it by clamping a jubilee clip around the ensemble.

The bung's sealing flange/cap needs to be the same diameter (or a bit bigger) as the port's O.D. i.e. the hole's + wall thickness's overall diameter.

 

sorry to butt in on ur post dude, but what is the size of the hose which fits onto the dump valve itself? Reason i ask is because i pick up my version 3 sti tomoz and am fitting a bov to it.

many thanx Den.

 

Post #7 of the below thread would seem to indicate that both ports of the v.3/4 DV have an O.D. of 32mm:-

https://www.scoobynet.com/private-sa...ump-valve.html