I am not an expert on the 1.8T engine or the KKK turbos, but here is what I understand (and from looking through the archives)

In terms of the turbos, both the K03 and K04 turbos are designed to handle 1.0 bar boost. However, it should be noted that many 1.0 bar chips only hit maximum boost (1.0 bar or 14-15psi) for short periods of time during street driving (even relatively aggressive street driving). People have reported problems with overheating on the track so it seems it is necessary to add additional modifications to the 1.8T for track purposes (improve cooling, etc.). From what I understand the K04 turbo is simply more efficient than the K03 turbo.

As far as the engine is concerned, everyone seems to agree that increasing the boost will cause additional wear and tear to your engine, but most people feel it will be minimal. As for boost above 1.0 bar... it sounds like you'd need to get a better turbo (better than the K03 or K04) and additional modifications will be necessary.

Good luck!

Wayne
99 1.8TQMS

my impression was that the KO3 was only approved for 0.8 bar and the K04 for 1 bar. The 180 hp TT runs 0.8 bar of boost. Not sure about the 225 hp TT or the S4. Anyone know these boost figures?

KLHI
klhi@ibm.net
99.0 2.8QM Melange/Onyx Cloth

the K03 turbo is rated for 1 bar. Wett and several other vendors told me the company claims the K03 can flow 1 bar with no problems.

BDW

You have to ask yourself:
Would the factory *ever* run a component at 100%?
If the K03 is rated at 0.8 bar (which it certainly is), then the new TT is running @ 100% safe boost pressure.
The factory *always* leaves in a good measure of headroom.

Todd
Air & Water
www.awe-tuning.com

nt

KLHI
klhi@ibm.net
99.0 2.8QM Melange/Onyx Cloth

nt

KLHI
klhi@ibm.net
99.0 2.8QM Melange/Onyx Cloth