Just how much does direct injection carbon buildup hurt? B7 RS4 gains 42 wheel horsepower after 034Motorsport carbon cleaning

[George@BMS]

i know steelcurtain had a "how to" on mk5/mk6 on carbon cleaning the TSI engine. i assume it's nearly identical to the n54, sans 2 cylinders.

Lately 90% of my driving has been 1-5 miles, glad I have meth, but I still can't imagine what my valves will look like in another 20k.

Here is a TSI with a KO4 conversion. The TSI builds up slower than the TFSI although my findings have been similar in results regardless of what the build up looks like. The crusts around the rear of the port actually create a negative vortex reversing airflow either directly into the valve causing major turbulance. We must remember that we are flowing air only and not air that has atomised with fuel so its easier to affect the flow. This car has been running high boost most of its life so this decreases build up. I will try get a pic out of my archives with the valves open. Some TSI also have the ball that forms around the valve pretty low which drastically affects open valve port size as the valve opens and the ball moves directly in the opening.



Here is a stock Scirroco at 110,000km and it give you the difference of the affects of boost (see the fluffyness. In this pic you can see a piece getting ready to dislodge at 3 o clock on right valve.