cheesy19866

hi i have a wrx 95 inport im wanting a dump valve or blow off valve what is better ? how do i fit it ?

phil_wrx

iTrader: (2)

both the same and to be honest if u didnt know that then dont try :P

scoobymy01

HKS SSQV mate thats what u need very easy to fit

cheesy19866

thanks mate i did think the did the same thing but got told from the boy i bot it off of they was 2 difrent things im new 2 this stuff lol

alcazar

iTrader: (2)

Your car HAS a dumpvalve already, it's a recirculating type, which is the type for your engine.

Do a search on here, see if you can find ANY tuners, Prodrive, Subaru etc recommending anything BUT a recirc type. Then ask yourself why not

If you really want to spend the money, you can get aftermarket ones that do the same job, recirculating type, but yours is plenty good enough unless you are thinking of going to a high state of tune.

DON'T put a vent-to-air d/v on if you value your engine over the daft noise they make

Alcazar

RJM25R

iTrader: (1)

Always wondered why a vent to air dump valve can damage the engine. Could somebody explein?

scoobymy01

Me too as i have had aftermarket ones on 2 of the scoobys i have owned and since fitting the DVs there has been no problems with any of the cars whatsoever and they have covered approx 30,000mls with these fitted ? ? ? ?

alcazar

iTrader: (2)

OK, I'll try, but there are others on here who know more about this than I do. Trouble is they will no longer respond to threads like this, after a spate of detailed explanations resulted in replies like:"You get a VTA one mate, don't take any notice of the old f*rts on here. I've had one on my RS Turbo and it's been OK for ever".

Basically, it's to do with the fuelling. The air entering the engine is metered by a very accurate mass-airflow meter. The amount of air being sucked in has a big effect of how much fuel the car injects. Now, if the car is able to meter a certain amount of air, and part of that air is then dumped to atmosphere, ie: doesn't ever reach the cylinders, it follows that EXCESS fuel will be present in the cylinders. This causes bore wash, removing the lubricating oil in the upper cylinder, and can cause the piston to seize. It also gets blown out as raw unburnt fuel and can "fatally" damage the cat if you have one.

TBH, if VTA d/v's had any advantage, tuners would use 'em. If they didn't cause problems, SOME tuners would use 'em.

NONE do, NO-ONE recommends them, from Prodrive down. Ask yourself why.

In the end it's YOUR engine, but I know of a few people who've had major problems attributed to them, and LOADS of others who took them off and immediately noticed better running. Your car, your choice

Alcazar

fastfu

iTrader: (1)

one thing i will say is if you are only doing it for the noise consider fitting an induction kit instead as it wont **** up your air/fuel ratio but will make the factory dump valve more audible and you will also get a bit of waste gate chatter

Peanuts

iTrader: (15)

you will not get wastegate chatter from fitting an induction kit. ever.
thats just plain crazy to think you would.

fastfu

iTrader: (1)

i always did with my old classic

pinchers

iTrader: (1)

But when the Re-circ BOV is dumping it is piped between the TB and the air filter so the pressure from the dump will be pressurising that line, TB should be near enough closed if it has just dumped and that means the pressure has only one place to go back out the air filter or in that direction, i dunno just see it hard to understand how the MAF accounts for that, maybe if the MAF was between the intercooler and TB and the re-cirv dumped there.

I dunno im just trying to understand how it can be bad for the car if the air can escape and then inst really metered.

pinchers

iTrader: (1)

Hah drew myself a picture and re-cirv BOV makes sense