Been driving my w201 with OM603turbo for a while now, and like it. Everyday use is ok, fuel economy, when I can control myself is also good, and my best laptime so far on the Nurburgring is 9.00 min exactly BTG, with standard engine, no intercooler, yet.

Couple of days ago I found an om606 for a nice price, without IP and turbo, but with the manifolds.

The plan in a couple of months is, to take the OM603 out of my w201, and put it in my w123T, and then put the OM606 in the W201, to take some seconds of that 9.00 BTG time .

Some questions:
-is the OM603 pump an exact fit on the OM606?
-Since I need to buy a turbocharger for the OM606, I might as well buy an upgraded one. Are there any upgraded turbo's which fit on the triangle-shaped exhaust manifold? Or do I need to make a custom manifold? Anybody got any pictures of a custom made om606 manifold?
Plan is an increase in HP: 250 BHP would be nice!
Plan is, off course, also to send an OM603T pump to Myna-diesel, for bigger elements.

Thinking turbo, no, twinturbo!

Mostly I would use my car on the racetrack (nurburgring etc) and everyday use. I was thinking: Holset may be nice, but maybe very late spoolup? Not ideal for fast laps in think.

What about fitting 2 VW TDI 110 bhp variable turbos on the om 606?

Not much room for them, but quick spoolup?

If you want Holset, go with an HY35. The 9cm housing will spool much faster than the HX35's 12cm housing and it's still capable of 35psi.