Blow off valve b4

How's it going. New to this site and to the scoobys!! I am lookin for a dump valve for a 01 b4. Does anyone know were I can get one and recommend any? Thanks

Hey man, HKS SSQ dumpvalve would be most people favourite as far as I know. It is good build quality and sounds pretty sweet too

Were can I pick one up?? Will it affect the car in anyway?? Even more petrol been used!!!

I had one on the car before-a HKS SSQV. No difference to fuel economy,I just though the car felt better without it. If you really want one-get on to japanparts.com and prepare to part with €200 approx

Hi Moro. While lots of folks fit them, and I'm guessing you mean an atmospheric BOV that makes your car sound likes it's sneezing between gear changes?, I see your second question was "will it affect the car in any way?" There is on line info to be had but among some tuners, there is the feeling that these are not good for the engine or performance in road legal cars. The air coming out of the airbox is measured by the MAF (I'm pretty sure the 01 B4 is MAF based, anyone?) and gets sucked into the turbo(s) and forced into the IC. The MAF has told the ECU how much air is coming down the pipe and the correct amount of fuel is added accordingly. With a re-circulating valve, when you change gear, the sudden overload of pressure in the IC is passed through that valve and sent down a pipe to the inlet manifold, so, still the same amount of air and the correct fuel/air ratio. With an atmospheric dump valve, that extra pressure is vented to the atmosphere but the original fuel quantity is still added after the IC and now the mixture is rich, which is not good. I have read that in extreme cases it can cause stalling or misfiring although I'm not sure about that part, but the incorrect fuel/air ratio thingy is right. So while you might have the sound you are looking for at the same time it might actually be detrimental to the performance, and for €200 too, sheesh. I'm sure there are some technical experts on here who can assist in confirming or contradicting what I've written here.

great reply Fozzy!! totally correct! changing the recerc valve for a vent for atmosphere is not good on the leggys and also the Imps but many people tent to ignore it in favor of sounding cool lol!

i cant really add anything to what Fozzy said really haha

you can if you REALLY want a VTA BOV go "MAFless" but would you pay hundreds quid to run dump valve, even before you buy the bleddy valve lol

It really does make the car overfuel. It usually needs a remap after fitting a BOV.....mainly because of all the info Fozzybear detailed which is a great write up mate

If you don't remap the car then you may notice the car nearly stalling, expecially when in traffic, due to the overfuelling issue. This is only my personal experience from not having remapped my car yet. I was chatting to Martin Tracey about this also and he 100% agrees with the stalling and the need for a remap afterwards. It isn't a huge issue regarding the overfuelling. It just means you will use more fuel because the ECU doesn't know what is going on I have found my car popping a lot more flames with my turbo back straight through exhaust and BOV

You can pick up a second hand HKS SSQ BOV for about €130, or a cheap one for less again.

The car will overfuel slightly when the valve operates, it will not make the car overfuel in general throughout the rev/loading range. It is not really overfuelling as such as the car is fueling correctly for the air that "should" be in the system but gives that effect due to the lack of air in that moment. So you will still use the same amount of fuel. Normal operation resumes straight away once the valve closes again.

If the car is nearly stalling or having issues, then i would suggest you have a problem with the dumpvalve because it wouldn't cause those issues if functioning 100%. With a remap, the mapper can map in pops and bangs with the atmospheric dumpvalve upon valve activation but it would be a complete waste of a remap to map just for a dump valve.

Sorry Moro, Sweetcakes defined an important point there, the overfueling issue will only occur during the vent to atmosphere which is usually during gearchanges, however, the crucial issues pertaining to that split second overfueling remain relevent.

Well that was a serious write up and thanks fro the info!! I think im goin to leave it is and not touch the engine!!! HAve to say every day i love the car even more!!! Just needs a couple of personal touches...thanks for the info tho!!