adam cupra 20vt

Built Not Bought.
Mar 31, 2005
6,157
2
Mud Hut
I was talking about the whole atmospheric valve thing with my mate who used to work for a small motorsport company, he can't understand why we can't run an atmospheric valve as long as its twin piston?

He was saying bailey actually sell the valves with a fitting kit that includes a blank for the 1.8t.........and where he used to work they fitted quite a few to golfs and never had one come back.

I said to him its always debated on here and that some people say the ECU relys on the pressure being dumped back into the TIP and would eventually read this as a boost leak?.............he thought this was a load of crap because the TIP is after the MAF sensor so in theory the recirc valve is dumping un metered air so it wouldn't matter at all if it wasn't recirculated?......he argued that filters giving different air flow don't register a problem so how would the ECU know the valve was not in recirc?


Is there a good argument why people can't run a twin piston atmospheric valve or is it just forum myth?
 
Also i would like to know what the difference is??? I am abit thick and new to turbo cars but i am trying to learn fast. Is there any benefit to the type you have mentioned to the more standard fitting Forge 007p??
 
Beneft of the recirc valve is it dumps the air back into the system.

A atmospheric valve dumps to atmosphere hence the noise.

You can get ones that do both.
 
Beneft of the recirc valve is it dumps the air back into the system.

A atmospheric valve dumps to atmosphere hence the noise.

You can get ones that do both.

Is it not picked up by the MAP sensor though Adam? As in the deviation between MAF signal plus expected recirced air and MAP signal is too great?
 
I don't really see how it can be mate as its post MAF?

The map senosr is right the way round the other side of the cooler near the TB and I can't see how it would make any difference?

And the twin piston means the system is always sealed like a recirc valve.

Unless I'm missing something?
 
I might be wrong mate but I'm always seeing people on the golf forums with atmospheric DV's and I've seen people on here.

The HKS BOV is also pretty popular.

I can see why the single piston ones would cause a problem but not the twins?
 
im gonna try with my mates bailey tomorrow when he come round, always wanted to see for myself what happens. being on here i expect limp mode well just have to see.
 
im gonna try with my mates bailey tomorrow, always wanted to see for myself what happens. being on here i expect limp mode well just have to see.

Make sure its a twin piston one DV26 [there 2 different sorts] and you blank the TIP connection off.

I think they actually sell the Bailey kits for the 1.8T leons?
 
Make sure its a twin piston one DV26 [there 2 different sorts] and you blank the TIP connection off.

I think they actually sell the Bailey kits for the 1.8T leons?

s1pru dan used a hks ssk for a while; might be worth talking to him about it?
 
by the way there is loads of vw bora's on youtube with atmos dv, i have read through some of the comments and none of them seem to have any probs. 1 thing i would say, my forge split r always brings up a fault (boost leak) but i no loads of people have this with the split r dv!
 
Make sure its a twin piston one [there 2 different sorts] and you blank the TIP connection off.

I think they actually sell the Bailey kits for the 1.8T leons?

yeah its definatly twin piston, he got a kit it fitted to a golf gti. hopefully the blanking plug he got will be the same size. let you know what happens
 
yes tip is post maf, but this IS measured air as it was measured when it passed the maf, if this air then gets dumped, then more air will pass the maf during dumping than by recirc?

I don't really get it? the air has already been measured and the recirc port is the other side of the MAF so how can it measure it?

And how can air dumped back the other side of it be measured as its behind not infront of it?