I have 2 questions that go hand in hand. First of all, I am thinking of upgrading the K03 in my 00 Audi TT 180hp to the K04.

1) Would a reprogrammed ECU be necessary?
2) What power gains should I see with just the K04 and ECU tune and no other mods?
3) What is the best chip out there and will they accomodate for a K04 on stock injectors?

I would eventually go with a mild 2.5" exhaust, but for now the ECU tune and K04 are in the budget. I think this will set me close to what a TT 225hp would be. Thanks for the help in advance.

 

does the 180hp motor have the k03 and the 225hp motor have the k04 or do they both have the k03?

 

The 180 has a K03 and the 225 has a K04. The upgrade for a 180 to is the K04-01 which is still smaller than the K04 i the 225. If you want to use the 225 K04 then you will have the get the 225 manifold and a custom made downpipe. For the money I would go with the new ATP eliminators that just came out. You can do a turbo swap from the K03 to the GT2X and not change anything out and will get more power than with the K04-01.

 

If you want even more hp and you have the quattro model, go with the GT2871R from atp turbo. You'll also want there fueling kit witch is larger injectors and software. To take advantage of its potential you'll need a 3" downpipe, exhaust manifold, intercooler, new clutch once the old one goes. But, first off those all aren't necessary if you just want a simple turbo swap, you can do it with one of their "eliminator" kits.