Dump / blowoff valve

[adamsdubbing]

Is it a bad idea to put a dump valve or blow off valve on my vr4 I've been told that the to atmosphere ones are a bad idea? But then some people use them? I'm confused what to use as I really want the sound lol
Plus what's the best way to mount one?
I've also been told that the evo ones fit??

[dazjb]

Air is monitored as it goes through the MAF, the ECU is told this figure and based upon this can calculate how much fuel to inject. When you fit an atmospheric blow off valve this air that has been monitored is released into the atmosphere .. the ECU doesn't know this though and still injects enough fuel to cover what the MAF tells it is incoming. The result will be a momentary rich mixture. The way your car is tuned will determine how drastic this is.

I have never ran a MAF on a VR4 engine though so cannot say how severe this is on these.

[Nick Mann]

I run an atmospheric bov. They can sometimes cause stalling and as above a brief moment of richness.

Evo bovs have been fitted to VR4s in the past.

It's your choice really.

[Davezj]

i have an evo one fitted to my car and it run ok.
can't say i noticed a difference though. they miht have a slightly stiffer spring but not be much.

If you really want to run a BOV then disconnect the pipe that goes from the recirc valve to the turbo inlet and block the pipe to the turbo inlet.
the standard recirc valve will vent to atmosphere now.

i did this for a while accidently, as my pipe that goes to the turbo split and vented to atmosphere but the turbo was able to suck unmetered air into the turbo which is what you do not want.

[Pugme]

I ran a sard r2d2 for ages and now have a hks ssqv because me and my housemate swapped from his s14.

I can't say it's had any detrimentalk effect on my car and I love the noise