I would assume it would cost about $800-$1200 per head but I've heard it can add ridiculous amounts of power to the engine. Just wondering if anyone has ever had this done, heard of anyone who had it done, or heard of anyone who offers the service. I'd be interested if anyone has had it done to other engines/cars also. It seems like the next logical step after, suspension, chip(which I don't want to do), exhaust, wheels, brakes, downpipes (which aren't offered for the A6 yet), turbo upgrade, etc. etc.

TIA!

-st

If the ports are very rough or the manifold and ports are badly mismatched or if you are willing to remove lots of material and enlarge the ports substantially then you can see some real gains. On newer cars with modern casting methods I think the realistically obtainable gains would be modest, much less than chipping. Also realize that ports are not designed badly on purpose by the manufacturer. There are tradeoffs between throttle response and where in the RPM range the car should make the most power. Finally, polishing is essentially for looks. If you look at the airflow next to the port walls it is obvious that smoothing the ports will have virtually no effect on air flow, unless there are big chunks of slag left behind from the casting process (I have seen this sometimes on very old american cars like some 215 Buick V8 heads 1963).

Porting is also much more intrusive to the engine than chipping or going to bigger turbos. You will have to remove both heads, which means all the intake system and wiring and also the exhaust manifolds. On a turbocharged engine you will also have to take great care reinstalling the heads so that the head gasket does not leak.

If you don't want to chip then I would look at exhaust upgrades since this would probably give you at least as much power and may not cause any warranty issues (although the new exhaust would certainly not be covered).

You are racing and you need that extra 1-2%

or

It is an old style motor with lower technology heads.

With the way that new motors are designed using CAD technology, they are already pretty much optimized for flow.

wondering about this since someone at work had mentioned it to me. Thanks again for the info.

-st