I'm a new member to these fourms and I would like to say that they are very informative. I bought a 01' audi a4 quattro 1.8t. I put a greddy profec e-01 on it. I'm setting my boost levels at about 14 psi. The car pulls strong and steady at 14 psi untill about 4800 rpm and then the psi drops to about 11. Have no idea except maybe the ko3 can't be stable at higher rpm at that boost???? I have been reading a lot of fourms for this awnser but no one has had this problem it seems. I have read about this diode mod for the map and going to do that. I also noticed that some people say that the stock boost controller needs to be plugged in even though its being bypassed? from a electronic controller. Also another thing is that while reading many posts, quite no awnser as to if the 01' has the ko3 or the ko3-sport on it.

 

Well your trying to run more boost on a stock ecu than your supposed to. That is a bad thing. Turn it back down to 10psi or so until you get it chipped or do the diode mod. After you do this you can run more boost safely. And the reason it looses pressure is because the turbo is not big enough to move that much air at those boost levels. Oh and yes, you have the K03-s.

Josh

 

what is a good boost level with the ko3-s and whats the max? After the diode mod.

 

could the stock BOV be leaking boost at higher rpm??

 

you dont have a BOV, you have a Diverter Valve (DV). the 1.8T is set up with a closed turbo loop and the DV redirects the air back into the airbox. DO NOT put a BOV on your car. When you chip, put on a Forge DV or APR R1 or any other aftermarket DV you like the sound of

 

^ Apparently someone doesnt read the forums, forge004 works well with the 1.8t.

Josh, he has a 01 and running 14psi is fine. After the diode you can run 18psi.

The 01 comes with a ko3s which has a 8 blade compressor wheel that is a little more efficient than the older ko3. But the same still applys that its tiny and cant handle the flow above 5k and it will drop off fast. It was used for its lowend tq and not high end hp. With a chip, you can run 22-23psi daily.

FOr a diode how-to, click A4 in my sig

 

Oh yeah, I forgot about that. You have a MAP sensor in your car so it will be able to adapt for the extra boost. My bad. Thanks for pointing that out Cincy.

Josh

 

so if I have a SSQ BOV I need to get the recurculating adapter? What chip is recommended for the 22-23psi. So all I have to do is Diode mod it and I can crank it up to 18psi. What were you talking about with the map sensor? Thats where the diode needs to be hooked up at.

 

no you wont need a recir fitting for the HKS, but that valve gets annoying fast.
Any chip will do 22psi\
Yes on every about the diode

 

So in theroy if I remove the DV, plug the hole on the intake it leaves or re-pipe it, put my HKS on it to open atmosphere, the car will run fine with no rich fuel problems at shifts.I know that on cars with re-cirrculating BOV's like DSM's, if you change to open air the carruns rich at shifts to compensate for the pressure being forced in after the mass air flow sensor.