I have a Rocketchip 2/3 in my '99.5 ALH. It is fantastic. MUCH improved performance with virtually identical MPG; however...
With a 2009, I'm planning to wait until the 50k warranty is up to even investigate chipping. The performance on the 2009s is good from the factory, so there's less value in "chipping", and I think there's less room for improvement due to the higher turbo boost levels in the base ECU program.
Well, the warranty isnt 50k, so your wait will be 14k shorter.
Timing in TDI's is fuel timing, at least that is my understanding.
Say a stock car injects fuel for .1 seconds total starting at 5 degrees from TDC, (im making up numbers completely) a chip can start injecting fuel at 7 degrees from TDC for .15 seconds for instance, giving you more fuel and more power.
A chip can also tell the turbo to supply more boost (more boost=more power usually), or a number of different things that people like me shouldnt be messing with. Luckily, theres people like Jeff of RocketChip or Alligator (or however they wanna spell it), or I think theres another company or two.
But for 09's, your out of luck right now, the exhaust system is too new. I believe the reason there isnt a rocketchip out right now for 09's is the fact that people are idiots and will blame the chip WHEN their DPF needs to get replaced in 6 months. Yes, there is a reasonable demand to put these things on the track, but again, people are idiots
Also, the TDICup is using the exact same car minus a couple parts as the ones we own now. Except their engine is 170hp, ours is 140. Some people have gotten the 90 hp earlier models to put out close to 200, I would bet that 200 hp is a single chip away with the 09. And if you get crazy enough to spend another car on this car, id bet 250 isnt too hard.
Advancing TDI timing is simply advancing the injection pulse (as stated above) - this gives the engine more time to burn the fuel (thus extracting more work out of the fuel and reducing smoke). It does not inject more fuel.
Timing can be adjusted in small amounts via the ECU and large amounts via the IP. In most TDIs, the ideal timing is just below the "advanced" bar in VAG-COM - so the timing is considered advanced as as VW is concerned, but for most of NA that's about where it should be stock.
A lot of the tuning that's done on TDI's (at least for the ALH engine) is done to overcome the ridiculous restrictions and hinderances placed upon Diesels in NA. The laws and regulations more often do more harm and good, so chipping your TDI is doing everyone a favor in terms of environmental and performance issues. A properly tuned TDI will be more fuel efficient than a stock tuning in NA - in fact, if you take a European ECU and drop it in a NA TDI, you'll see an immediate MPG and power increase with no other changes.