I have just fitted a forge VTA dump valve to my PPP 07 STI it pops bangs and farts like a good un, why is this and will it cause any damage?

 

In basic terms, it's venting the air, so adding more fuel. Causing rich running.

Bad fuel econ & car drives badly. All for a pitush noise.

 

Me thinks 1 nearly new Forge Dump for sale on ebay

 

It wont be the first and certainly not the last.

 

ive got a simple baileys one on my scoob. car runs fine and pops bangs away. have to give some throttle for bangs etc, but setting off all those tosser beemer alarms would be worth an engine rebuild

 

Does it or can it damage the engine?

 

Don't know if the running rich would go as far as bore wash.

I'm sure once mapped, they are fine. But until then, i wouldn't bother.

 

Nowt wrong with forge products....... well made and better than most.

 

It's debatable as the whether it will lead to bore wash, but it may so that's obviously not good. As for mapping it out, not so easy unless you go for a new ECU that doesn't use the MAF sensor. Otherwise re-mapped or not the extra air flowing past the MAF has to have fuel added, if it's not the dump valve (and the ECU has no way of knowing its open) then it will run lean. That's bad too.

Stick to the re-circulating dump valve and you can't go wrong. The one fitted by Subaru does just fine, no need to upgrade. Why waste your money, spend it on something that does actually improve the performance of you car. VTA dump valves don't they just make a silly noise and cause potential running problems with the car.