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Had my b7 since feb, had it on the rollers in March and I was under no illusion that it was producing factory power. It made 322 which was I put down to it needing a de coke.
Other things took priority but at the weekend I got stuck in a cleaned the inlets of the black stuff. The pcv valve seams to be passing as the inlets were quite wet, this is a job for the next time I'm home
I also put a revolution intake on, which again I knew wasn't going to give me a increase in power.

So today it was back on the rollers and it made 330 all be it with the piper cross filter removed. With the brand new filter it made 309...

So my question is, what else can cause this huge power loss and how can I correct it?

I have a polished and ported manifold waiting in the wings and I plan to get a miltek and a map. But until seeing almost stock power I don't see the point...

Any ideas?

sounds like a vac leak

100%
the PCV is vacuum controlled and fragile.
But you really need to get the vacuum system tested. If the leak is significant then the manifold tumble flaps will slowly close and starve the engine of air by at least 50%.

toyneg wrote:sounds like a vac leak

+1

A vac leak typically causes a MUCH bugger power loss than carbon - yet most people think carbon is the big power loser?

So many things on this engine are vac controlled that if you have a big power loss a vac leak should always be the first thing to investigate.

Yep as said above sounds like a vac leak. No way will a coked up engine cause that much loss.

toyneg wrote:sounds like a vac leak

Another +1 to this... get a deflap amd a stage 2 map and discover your new car...

Yes agreed would appear a vac leak

But since owning the car since Feb, have you had warning lights on ? Re engine management

Have you connected VCD's for anything?

No in the last 10 months it's never missed a beat, the manifold will be going on once I'm back from work in two weeks along with a new pcv valve. Going to research how to test the vac system in the time being.got a mate who's going to plug his lappy in to see if there's any codes lurking. Looking forward to getting it sorted and having a "new car"

dead easy. Just get a vacuum brake beeling kit with a gauge.
Take off front carbon cover.
there's a bunch of vacuum cables there and it's a case of disconnecting and applying some vacuum and see if it holds.
A good simple test is to run the car for a few minutes to build up a reserve. Then switch off and the wait a few minutes. There's a vac line that runs to the airbox and this has a join. Disconnect it and if you hear a good solid "pssst" then it's not a bad start.

Hopefully get it sorted next time home. I noticed the air flap in the factory air box was stiff when I removed it for the revs kit. Was hoping this would sort it but hey ho...
I'll get it sorted, just really annoying as after the new intake and de coke it felt quicker on my arse dyno hahaa

leericho wrote:So today it was back on the rollers and it made 330 all be it with the piper cross filter removed. With the brand new filter it made 309...

Your car made 21 less HP with a filter in vs no filter?! That sounds crazy to me