So, owning the 12V is a major difference from the 30V I had before. What sort of custom modifications has everyone done to the 2.8 12V?

When I get back in the spring, I'm going to build a custom exhaust to have true duals, AI, upgraded suspension and upgrade to slightly bigger injectors to start with.

I've been reading about people porting and polishing the TB, and intake manifold, custom mounting an Eaton m62/90 and FMIC, but didn't toughen up the top end? I haven't been able to find a decent thread on lowering the compression from 10:1 to something that can provide 10+ reliable PSI. In fact, there isn't a whole lot on engine rebuild parts for the 2.8 at all, unless I go through the German market. I saw somebody mention an upgraded manifold, and under drive pulleys. I'm not sure how much of all that was custom made or not though!
In all honesty, I'll probably end up building up the car as a flashy DD,with a few extra ponies, and just buy something else to go super fast in.

6 years ago I used to know all the 2.8 terms, where to look, what to buy. I've been out of the game for so long. That middle year was a 2.5TDI, wish I could have brought it back! That was a fast car!

 

Most of the 12V upgrades that I've ever seen are on the Audi 90, B4 forums. The intake port/manifold matching is said to make a difference, obviously forced induction would. My '96 A4's engine is all stock, the only thing I've done for airflow is remove the MAF screen, and I can't say that really increased the flow, as I never logged it. "Bigger" injectors are not going to help unless the airflow increases much above stock level. I did change all my injectors from the original two-hole to a later four-hole type (because one failed), and I'd say it runs smoother and gets decent mileage; 30 mpg at 70 mph cruise. Make sure the dual-length changeover actuator works, or your top-end power will suffer. Rev in neutral to over 4,000 rpm and watch the linkage at the rear of the manifold to be sure it moves full travel. Of course check that your compression is normal on all six cylinders.

 

I have long gotten past adding any serious power to the car. The PES G1 is almost an exotic SC found in myths and some lucky guy's garage. I was looking at the new 4-port injectors too. 30MPG at 70MPH? That's awesome, that's almost 6mpg more over stock numbers! I was getting upwards of 50+ with my TDI, but that's European fuel for ya.

What are the numbers you are looking for when checking compression?

 

I can't remember just what the compression spec is, but the last time I checked mine, several years ago, all were around 180 give or take 5 PSI. For an engine with 253,000 miles, it runs really well. I wind it to redline at least once per day, either on the freeway onramp or up one steep road, so that the engine puts out maximum output for perhaps 10 seconds. I've had it up to 7,000 rpm, because of not paying attention to the tach, but it ran flawlessly. A Hyundai engineer that I know was astonished that my almost 20 year-old valve springs didn't break!