SBAlexanian

I have a b5 1.8t and the oil seals on my K03 went out so I swapped in a K04. Finally have everything running properly and looks and sounds great. I decided to give it a test run, push it, and see exactly how much boost I was pushing. Boost was spiking at 18 PSI and averaging 16. When the boost peaks out at high RMP the vehicle bucks, severely. Any Ideas?

AudiMick

Did you update the ECU to support that bigger turbo ?

If not it's probably not surprising, running like that is only a temporary measure.

Did you update the DV also? Stock valves do that kind of thing.

SBAlexanian

I have not upgraded the ECU, but I've been monitoring how my engine has been preforming via scan tool. Fuel trims look good, so does my IAT and other systems that could cause the Issue. I am looking to tune soon, just cannot afford it yet. I'm hoping the ECU will relearn and compensate for the significantly higher boost soon. The stock DV is still in place. I had a sneaking feeling the stock DV was going to cause some sort of an issue. I just cant go out and buy a better one not knowing for sure if its going to fix the problem. Do you know what sort of boost the stock DV is rated for/ capable of? I know the K03 was limited at 8.7PSI so I can't imagine the stock DV handling double that.

AudiMick

I think you can use a stock N710 DV from a 225 TT which has a K04 as standard. Did you check your plug gaps also, coppers work best at high boost with a smaller gap IIRC. Change em every 5k.

SBAlexanian

I just put brand new NGK BKRE7 plugs in, gapped to .028. I'm going to go with an r1 diverter valve from arp, I found it new for 115 on ebay. Thanks for the input

SBAlexanian

I went with the bosch 710N. 49 bucks shipped. Thanks for the help mick