dump valves....v.confused...!!!

[trevelyan]

ok, here goes....!!

im' looking at getting a new dump valve, but not too sure about the differences between an atmospheric or re-circulating one?

which one would be suitable for a 99 uk turbo...??

also i've heard that baileys dump valves are pretty shi**y, so can anyone recommend a decent manufacturer..??

Cheers..

pps... when is the next glasgow meet..?  looking to come along to say hi and meet all those peeps who keep giving me friendly waves..!

[RS Grant]

Forge, HKS & Blitz are the only ones that I would buy... IMO, when buying mods, buy the best there is... otherwise you'll more than likely have to buy twice when it fails to do the job properly or gives up completely.

Vent to atmosphere arent actually needed until being used in Big Boost, Big Turbo applications..

Cheers,

Grant

[wrxmania]

I have a Forge recirc - very good quality and you still hear it dumping (like my standard one did) but will not cause any bore wash (or whatever other) issues []

Brian []

[fai17]

Forge for me[]

[colzo]

I had a Forge VTA on my P1, it felt a bit jerky and I got a bit bored with the noise (what I bought it for) after a while. I personally wouldn`t get another one. Standard one does the job just fine. []

[wilky]

A dump valve does exactley what it says. It dumps the pressurised air being forced into your engine when you lift off the throttle to slow or to change gears etc. It dumps it because if it doesnt it would stall the turbo as it surges back round the system when you lift. If you have a recirculating valve, which is fitted as standard anyway, this returns the air into your induction system which is good because that air has been accounted for by your MAF sensor as it was sooked in. If you vent to atmosphere and dont put it back into the system and do not have the car remapped to account for this, then when you lift the standard or unconfigured ecu will still have this air as being present, and supply the fuel that that air would need, this means that the engine will suddenly momentarily run rich, in extreme cases causing bore wash, thats when your cylinders get too much fuel, and there is so much that some gets washed by the pumping pistons and into your oil, thinning it, or worst case, kaboom. Very rare but worth mentioning.

The difference in type is thus.

And governed by which noise flicks your switch, or how your car behaves. Some see very little ill effects with a VTA, some do.

Personally on a standard ecu I would go with recirc.

On my car running a non standard ecu and not having a MAF, I run VTA through a bailey dump valve which gives me no problems and chirps like a wrc car.

Mind you, I am running 1.8 bar and technically my car is a wrc car but the bailey DV is more than up to the job, but does get looked at regularly just in case.

Callum W