14N-FR

iTrader: (3)

I am now running a GFB dual port Stealth. Its an awesome bit of kit that can be set to atmosphere (should you need too) or returned to the inlet like standard.

I had to upgrade from standard as my standard one was passing at 1.55 bar of boost.

alcazar

iTrader: (2)

It's because your SSQV is dumping metered air to the atmosphere. The ecu has fuelled for that measured air, so without it, you get overfuelling, which causes borewash, (so check the condition of your oil more frequently and change it AT LEAST every 6 months), and some unburnt fuel goes through the exhaust valves, through the cats, where it might cause probs if you HAVE a cat, and can ignite in the exhaust: pops etc.

chaffe

iTrader: (1)

But would it though? surely the ecu cuts fuel on overrun to meet emmisions standards? usually above 2500 rpm with closed throttle ( the exact conditions a dumpvalve would be dumping) just a thought

dan83590

I had a really good dump valve fitted when I had my classic and it came free with the car and worked very well. Every time I changed gear I would wind the window down and shout I'm a **** from the window.

JohnD

iTrader: (5)

Part of the engine mods on my STi include a cold air intake system and the standard dump valve is now audible, annoyingly. I've tried both foam (Hyperflow) and cotton (K&N) filters with little difference between them. Fortunately, it's more noticable inside the car than out.

JohnD

J.beazley

Another thumbs up for keeping the OE valve, my '53 plate wagon is running a good 279bhp on 1.28 bar of boost. The only thing is that it gets audible higher up the revs rather then low down.

JayB