Remember I posted about a ProCharger centrifugal supercharger a week or two ago when I saw something on tuner transformations on Speed?

When I did that, I sent an email to Wetterauer America and asked if they wanted to develop a chip for a supercharged A8 4.2.

This was because one of the Chicago guys stated that they would do something like that.

I got a reply, and they went back to Germany, and stated they would be interested in the project.

Anyways, I'm don't have the time right this second to develop some kind of spec for a low pressure supercharger....but I'm thinking....

If they would do that, then why wouldn't they develop a chip for our 32 and 40 valve cars? I'm sure they would.

Actually, I'm making a sales call in Michigan tomorrow, and they are in Valparaiso, IN, on my way back. I might just stop in!

pw

In the S4 world when we increase boost we also have to advance timing and increase fuel. The stock components can only go so far. To get the most out of bigger turbos we also need bigger injectors and programming to match.

A simple low-pressure supercharger, centrifugal and not roots-blower-based wouldn't need the extra toys.

It's kind of like adding nitrous to a Chevy smallblock. You can add a 100 shot, dry-system up to a point because the maf and injectors will compensate for the increased oxygen and pressure, but after a sepcific point the car will be too lean and can't increase the fueling enough to get a good mixture.... Anything larger and the system has to be a "wet" system with larger injectors, modified programming, etc.

Turbos or a supercharger will increase the air pressure and therefore it the air going into the engine will be more dense. It will have more oxygen and after a while there will be too much O2 and the injectors won't be able to compensate for a good mixture. It will need a chip and possibly injectors to make the most out of the increased air density.

After upping the amount of gas to match the amount of air the next weak link becomes the engine components themselves; the crank, connecting rods, rings and pistons. From what I can gather the 2.7T engine in the S4s is pretty industructable, with folks regularly running close to 20psi (16-18 with a big stage 3+ setup.) I believe the same can be said for the internals in the ABZ (4v) and ABW? (5v) V8 engines, given the setup on the RS4.

One of the tricks is to use a 'master boost controller' or MBC. It's a mechanical valve that is used that when a maximum amount of boost is achieved it kicks in the vacuum line to open the wastegates. You don't have to worry about electromechanical control of the turbos that way; you only have to worry about the computer matching the fuel/air ratio.

I'm mapping this out in my head and wishing I had some winning lotto numbers!

For chip tuning Mihnea is the guy:
mik@info.fundp.ac.be
He knows his stuff but more importantly is rumored to have a motronic rosetta stone. Comes over from .be now and then to tune a bunch of I-5 cars... in real time to the individual set up.
I do not know his knowledge WRT the 4.2 but he could at least steer you somewhere.
WRT Wetterauer, yes they are convenient and I bought a stage I chip for the s6 from them a few years ago, but it was more for the eprom socket than the chip.. its a one woman one college kid (tech) office. There's not even a garage. ECU removed whilst car parked in parking lot. I dont know what they do when it rains.
Point is that a supercharged 4.2 would be a rare bird so be sure to inquire if they're going to have a real tuner on hand to tune in real time vs just sending 52 sets of chips to try out (aka guesswork.)
Also IME the ecu can contol boost way better and faster than any add on boost controller.
It would be awesome though if you could pull it off. Maybe a trip to where is it ... Brazil? ;)
My .0002
ps as you slide down the very slippery boost slope keep in mind further possible necessities, such as a very nice set of ceramic coated equal length tubular headers:)

The only thing they adjust with the ECU chip is the timing and the fuel map.