car lagging with new dump valve help!!!

[willie25]

ive just went and bought a dumpl valve for my00 wagon,its a forge bov,since ive put it in my car does not feel like its pulling the same feels like its got quite a bit of lag in it now,i bought the dump valve of kenny who is a member here.the dump valve itself is ok i got a bag of different springs with the bov could it be that the spring in the bov is too tight im new to subaru`s this is my first one any help would be appreciated.and thanks again to kenny for the bov who has a smashing car.cheers,

 

 

willie[]

[thefastone]

Do you not get more lag from Vent to atmosphere valves rather than recirculating valves? something to do with there not being the gas in the system to keep the turbo spinning?

 

I'm sure that someone will probably correct me on this though...  [Y] 

[willie25]

youre probably right mate makes sense didnt expect as much power loss tho.thanks for your reply.

 

willie[Y]

[colzo]

I had a Forge VTA on my P1 and found it quite jerky when accelerating.

[colin_ross]

Is then new d/v a vta? If so there are a number of "features" that you may have to get used to.

On a maf mapped car it will measure the airflow into the engine and deliver the right amount of fuel. When you dump the air out of the system it doesn't know this and will still chuck in what it though you needed. This leads to too much fuel being delivered and you can get jerky gear changes, pops and bangs, flames and bore wash (excess unburnt fuel making it's way past the pistons and into the oil).

The springs in the kit hold the dump valve closed so the more boost you run the stronger spring you need to stop it leaking out. If you run lower boost you'd run a weaker spring as the boost pressure wouldn't be able to push past the firmer spring. It's a bit of trial and error to find the right one.

As for your lack of boost I start by looking for a leak where you were working, check everything is tight and vacumm hose it secure and after that I'd try a stronger spring.

[willie25]

Is then new d/v a vta? If so there are a number of "features" that you may have to get used to.

On a maf mapped car it will measure the airflow into the engine and deliver the right amount of fuel. When you dump the air out of the system it doesn't know this and will still chuck in what it though you needed. This leads to too much fuel being delivered and you can get jerky gear changes, pops and bangs, flames and bore wash (excess unburnt fuel making it's way past the pistons and into the oil).

The springs in the kit hold the dump valve closed so the more boost you run the stronger spring you need to stop it leaking out. If you run lower boost you'd run a weaker spring as the boost pressure wouldn't be able to push past the firmer spring. It's a bit of trial and error to find the right one.

As for your lack of boost I start by looking for a leak where you were working, check everything is tight and vacumm hose it secure and after that I'd try a stronger spring.

thanks for that i will try changing the spring around to see if it makes a difference failing that i may just buy a recirculating one again saves any hassle with it plus i was told if i fitted  a bov it would void my warranty,thanks again.

 

willie.