RECIRCULATION VALVE - dump valve whats the difference?

I think you are refering to EGR - recirculation valve, its task is to replace the air whit inert gas (exhaust gas) to lower the consumption at low power requirements, while dupm valve is a valve to protect from overboost, when you are shifting, and the rpm (air demand) is also much lower, but the turbo is still spinning at higher rpm, and creating a higher pressure.

 

Milo he's talking about the recirc valve on the turbo not egr,

A recirc valve recirculates the air when you let off back into the intake where as a dump valve does exactly what it says. Dumps the air.

 

So a dump valve will see you lose some fuel economy?

 

Personally iv never been a fan of dump valves. In my head the way a dump valve works it will give you turbo lag cause it dumps the air then the turbo has to respool, thTs how I think it works. I may be wrong lol

 

Recirculating valve

 

I run forge recirc. Like I sai never been a fan of dump valves. They sound shit unless your cars running 600bhp lol. Just personal preference .
I know a few people who have had loss of power running dump valves .. So up to you really just what I prefer, don't count on what I said to be right but that's just what I think lol

 

Quite the opposite, releasing the pressure keeps it spinning and/or allows the turbo to slow down naturally rather than being forced to stop by the building pressure between the turbo and the closed throttle.

I don't quite understand this blanking plate thing or why someone would fit one. Apparently my car has a forge blanking plate, I know it has a dump valve. Bit harder to miss.

 

If this is the case why do they fit records as standard and not a dump valve? That makes no sense to me as according to that a recirc is damaging the turbo because it's being forced to stop

 

Recircs*

 

It's still releasing the pressure. The reason is because it's quieter and most people prefer this.
i don't though. If I want a boring quiet drive I jump in works fiesta van.

 

My guess/understanding is that the car has an air mass meter and the ECU is expecting some recirculated air to be available, then a recirc valve is used instead of a dump valve. The recirc valve won't be damaging the turbo, running neither could damage the turbo as unused boost will be forced back through the turbo.

 

Blanking plate obviously covers where the removed recirc valve would be. No point having a recirc and dump valve fitted at the same time both trying to do what is essentially the same job . Some people have neither the recirc or dump valve fitted and fit a blanking plate which will force the excess boost back through the turbo creating a very distinctive sound.

[video=youtube_share;Ng3K_JCk1kA]http://youtu.be/Ng3K_JCk1kA[/video]

 

Ooof, I know that sound and why it is not good.
Will running a dump valve lessen the cars fuel economy?

 

End of the day the car has been build and programmed/mapped to work with what is standard(recirc valve). So modifying it may possibly affect it yes

 

I doubt it would have a drastic effect if any at all. I wouldn't have thought that the recirculated boost is that vast to have a noticeable effect, but then again I've never replaced the recirc.

 

Recirc valve will keep the turbo spinning to stop it stalling, cant see the dump valve doing this as is plumbed into the main induction pipe a releases the unused pressure to air rather then into the side of the turbo.

 

Ignore what ive said, just had a read on it.

 

It won't force it to stop suddenly though, like the terrible sound in the video above.
Are the standard recirc valves adjustable and any good at handling boost above standard? On some cars I think they're just a plastic item.

 

I'm quite sure they're not, the forge recirc item can be adjusted with a coloured spring that corresponds to the stage of tune the engine is at. The standard is a diaphragm and the forge is a spring and piston.

 

Gonna hijack this thread for a bit as I need a bit of advice.

I currently have a forge DV and forge blanking plate installed. Im sick of the wooosh noise from the DV and was wondering how to remove it. When I remove the forge piping is there meant to a standard pipe that connects the 2?

What I mean is when I take the red (see below) T pipe off, what goes in its place?? Lol im sorry its very early and im very confused


And what sort of sound, if any, will I get with just the blanking plate fitted? Just need a change from woooosh. Was looking at getting a HKS SSQV but all I can seem to find is fakes

 

You'll get a chattering sound with just a blanking plate fitted, think rally car - whether you like it or not is all relative - I love it, much better than the daft whistling and whooshing.

Some people say it has the potential to cause damage, but the general consensus on here for years is that there is no issue with the Megane and I've never read of anyone having problems because of it.

I'll post a pic of mine later.

 

Get yourself a forge straight pipe

 

That looks good! Mine is just a plain black pipe that looks pants, not that it really matters but if you're going to fit one you might as well make it look decent.

 

Ahh nice one, I didnt know you could get chatter from the meganes! Will be doing that this weekend then.

Was the best thing about my Skyline, the turbo spool then the flutter, been missing it!

Do you have any videos or sound clips of yours mate?

Cheers!

 

Mine sounds similar to Jamie's 250 but louder (hard to tell from a vid though how loud Jamie's is). I have a Ktec induction kit, blanking plate and both exhaust boxes removed. Tbh the exhaust is a bit loud from outside, though it sounds great inside the car so I'll probably have the centre box refitted even though I'll miss the sound.

I'm definitely keeping the blanking plate though, I much prefer the chatter to whistling. At home with the little lad today so if I go out later I'll try and get a short vid.

 

Not not the best quality as I just stuck my phone down next to the gearstick (which is why there's an annoying noise on the vid when I change gear!) but I think you can hear it ok.


[video=youtube_share;7asEBOzcORQ]http://youtu.be/7asEBOzcORQ[/video]

 

That'll probably be replaced by a high pitched squealing sound in a few months.
Cant believe you'd take a gamble with your own car like that.

 

You seem to be an expert mate, would you like to point me in the direction of some threads where a blanking plate killed someone's Meg?

 

Where you get your cai from jamie
sounds nice that

 

Cheers jamie had a look on google
did you fit it yourself

 

Oh don't take it from me http://www.turbobygarrett.com/turbobygarrett/compressor_surge
Obviously by car I meant turbo, sorry I should have been more specific. A fairly expensive part normally, or are you looking for an excuse to go hybrid?

 

Couldn't find any failures so picked something up from google instead?

It's been covered many times that the Meg (and very few turbo cars) does not produce enough pressure to cause any damage, it's just air flowing back over the vanes. Your foot to the floor with the turbo fully spooled puts way more stress on it. If you're worried about stressing the turbo then I suggest you don't bother putting your foot down.

Better explanation from Meganesport:

 

Fair nuff, rather have my car complete though. It's not like dump valves are expensive, free in my case since I didn't buy it.
Any noticeable increase in lag?