As you may or may not know, I'm working on an H/DT entry. The machine work on the engine is basically done, I'll be picking it up next weekend.
Specs are 1.5L rotating assembly in a VW 1.6L turbodiesel block. The head is a 1.9L VW unit (bigger valves, better flow, larger pre-chambers than the 1.5 or 1.5L heads).
The static compression will be around 18:1, as compared to the 23:1 or so for the stock 1.5 or 1.6L engines (due to the larger head). This should allow me to run more turbo boost, while allowing the engine to live more happily at low rpm & boost conditions.
Anyway - I'm looking for help spec'ing a turbo for this engine. Ultimately, this engine should make somewhere in the neighborhood of 125-140 HP, and will turn a maximum of 5500 rpm. My target rpm in top gear will be more like 4500. If I need to shuffle gear ratios and tire diameters around, I can run more like 5,000 rpm target in top gear.
It will be water-to-air intercooled.
I'm trying to learn about turbo maps, but have only scratched the surface. Since this will be a race-only engine, streetable characteristics are not needed. Some of the turbos that look like they might work would be a GT2052, or GT2056.
Anyone with experience spec'ing turbos is strongly encouraged to weigh in on this topic.
Steve.