I have a 1.8t withturbo xst3 t4 kit on it I just ordered a flashed ECU from Upsolute and I also got 440cc injectors comming soon but as of right now I have a TAP ECU and I was making 18 pounds of boost on the stock Ko3 and now I make about 1 to 2 pounds of boost till 4000 rpm's and then I still only make 5 or 6 pounds. Isaw someone on audizine making 322 whp and 20 pounds of boost withoutinternal engine work? Why does mine lag so much and why am I not able to make any boost? Could it be because of the injectors and the ECU or what is the problem?The car is much slower now and I def need some help. I've seen a couple ofsuccessfull T3T4 kits on 1.8's regaurdless of how much people on these forums hate them. If you dont like the kit just dont post anything, but if you have any good information please post away.

 

Check for proper waste gate operation.

 

OK, from your post, i gather that you were running the TAP ECU on the stock K03 turbo at 18psi. Now you're running the T3/T4 hybrid turbo on the same ECU program, since your Upsilon ECU and bigger injectors haven't arrived yet.

I'm familiar with the T3/T4 turbo (by now, who isn't? It's been around forever), and I know it's a fairly responsive turbo with good power potential - in short, kind of a MacGyver turbo in that it can be adapted to almost any car and typically works out pretty well. Here's what I'm wondering: how much bigger is this turbo than the OEM K03 turbo? Not just in physical size, but A/R ratio, inlet/outlet diameters, charge air outlet velocity,etc. It could be that the force of this new turbo, trying to run at the same 18psi that your OEM turbo generated, is simply too much for your stock injectors. This would mean you're leaning out, and subsequently the ECU would initiate safety programs to protect the engine - cutting boost, pulling timing, possibly limiting engine RPM to a lower maximum. You might be better off (at least until the new ECU and injectors arrive and you can install them) getting or making a manual boost controller (not the best controllers, I know, but for a low boost limit they're fine) and setting it for 10-12 psi. If it is the turbo creating these problems, then it's a pretty good step up from OEM, and I'd bet that running it at 10-12 psi is gonna feel really nice on the street.

Obviously, it should go without saying that you should a) vag the car for any deep codes, and b) do as dankhound suggests and check thewastegate actuator for freedom of full range of movement on the actuator arm as well as solid vacuum line connections. Take a few minutes while you're in there and look around the general area of the turbo and any other areas where you did work during the install and make sure that first, all lines are connected, and secondly, that they're connected correctly and aren't split, ripped, or swapped among lines.

Hope it helps.