Not much boost at all with that size turbo, you really need to upgrade the rods. As for tune, I am not sure who has the best tune for the 2001 for that size turbo.

 

running 26 psi on a ko3? Wow,i have agiac x plus tune ,dv,cold air ,exhaust,
n75 j,running 18 psi ,drop to 15.I have read about other guys running 27 lbs on a ko3 ,wish I could but might blow the turbo.

 

Your X should hit 18psi in 1st/2nd gear and about 21psi in 3rd-5th.

I ran 20-26psi for a good amount of time and even sold the turbo years after I took the K03 out of my car. Have to understand my car was tuned for those boost levels, I didn't just raise the boost on a standard chip.

 

I remember about a year ago reading your info on your car.It came up when I googled something else,regarding boost.your info regarding boosting 26 psi on a ko3 got me so excited....My ignorant self,started planning a strategy to find similar power on my ko3s new beetle.Something I just remembered to ask you.Your car was not a turbo diesel was it?I started reading any and all DIY's I could find.I must have spent 6 hours per night for a year ,absorbing info,and trying to put my own twist on those mods.My beetle has the ko3s turbo and the larger injectors and wrist pins.The awv motor was a detuned hardware same as a 180hp awp motor.I was wondering why you could make 26 psi
while many others were making 15 ,or 18 or 12 or 8 psi.I installed a boost gauge to find out I wa sonly boosting 7 psi then it would drop right down to 4 .That pissed me off !!!So,I went on a mission,a mission I am still on .Turns out ,I love this little car.,and I love tinkering.I made a custom cold air intake,which greatly reduced my operating temps.Added a hi flow exhaust,Replaced or cleaned all the sensors ,reclamped most the hoses.Put in an mbc and gauge and diode .Still was only making 10 psi,but the boost spooled quick and held fast ,felt better.I was using the wrong diode .I needed a 3.,9 zener but put in a 4.3 .I checked out tunes and opted for apr.It made pretty good power but service was horrible and the tech level was low with the guys I was dealing with.I switched to giac,because I heard their tune was more agressive,got it back but was still only boosting 15 psi and throwing a cel.Put in new plugs and coils still a cel.I finally decided to make a boost leak testor and soon found a major leak,hose going into the intake mani had a 2 in ch long slice in it and was blown out.5 other leaks found and fixed and now pulling 18 psi.I have not done a 4th or 5th gear hard pull yet but have never seen more than 18 psi so I thought that might be it.I put a diode switch in
and will put a mbc back in ,to try to get better spool up than a leaky feeling n75j valve.I also read up on a quicker way to spool up.,by lengthening the wastegate hose,making it about 8 feet long .,and a small reservoir tank connected with a t, to the hose.This way it takes more time for pressure to reach the wastegate so spool is almost as good as like going unwastegated .
This mod is legit and dyno revealed quicker spool time by more than 50%

 

No it wasn't a TDI, just your standard 2000 A4 1.8t 20v with the ATW 058 engine. I was able to make 26psi because that is what my custom GIAC tune was programmed for by the owner of GIAC since I was sponsored by him personally.


You must be running a bleeding type MBC, the blocking type doesn't allow any pressure thru till it reaches the set pressure which means there wouldn't be any pressure trying to open the WG till the boost pressure is hit.

 

I have not reinstalled the mbc yet,since getting the giac x plus tune.I have the n75 j valve in and that s why Im leaky.I just installed a new tip today .What a job,difficult and not much room to work.I have the dual ceramic ball,spring mbc .I canged the spring from 5 lbs to 10 lbs and planning on putting it back in.Im just wondering if I should run the mbc and n75 parrellel.,
or just remove the n75 but keep it plugged

 

How much boost can be pulled without tuning?