Ok so I just put a boost gauge on my 1.8t and it starts off at about 8 psi at about 2500rpms but as I get close to 4500 it starts to fall off all the way to 2 psi if I do I fith gear pull it will stay at 8 psi untill about the same I did take it all the way up because of the speed but it did start to fall about the same any suggestions on where to start could it be a fuel issue I really dont know where to start any info would be great thanks !!!

 

A fuel issue is possible. Does the engine sound like it's dying or is it just boost that's dying? You could have a stuck open DV or DV that opens too early for whatever reason.

 

I dont really know what the car is sappose to feel like I only had it for two or three weeks it soumds like its still spooling so I guess start with a fuel pressure gauge is there a way to check the dv

 

I dont think the dv is stuck open like I said it hold boost for a long time if I spool up in fith gear but it always seems to fall about.the same in everygear around 4500

 

Ok so someone said the ko3 just dosnt lile to stay spooled up at high rpms is this true

 

K03 will drop PSI when it gets close to redline, if you are almost hitting redline each time it's dropping it could very well be that.

 

^Probably this. If you've never seen a K03 up close you'll be surprised how little it actually is. It's way out of its efficiency range above about 5k. Time for a bigger snail

 

True but not at stock boost levels. Yes if the car is chipped and is pushing 14psi or more. The higher the boost you try to push with the K03 the quicker the boost falls off, even the chipped cars will hold 10psi to redline. So this is not your problem seeing your only running around stock boost and falling off to 2psi by 4500. Sounds like a flow restriction issue, could be a clogged cat or even a clogged SMIC.

 

Theres no cat on the car I dont know what a simc is starts to drop at 4500 but dosnt fall to 2 psi untill 600 and it seems to fall off faster the lower the gear is to 1 the boost is there then gone time to shift 2 it hangs for alittle the gone ect. Ect. But 4 and 5 seems to not really fade at all maybe just alittle ill try and get I vid of my boost gauge up here

 

SMIC = Side Mount InterCooler. That is what your car has stock. It could be clogged with oil since the stock crank breather setup sucks in the oil vapor into the turbo inlet hose and it all goes thru the intake pipes to the engine.

What is your vacuum reading at idle on your boost gauge?