Ok Here is what Eiji at Datsun Spirit wrote.
Just hitting 400HP on a dyno shouldn't be hard at all for a turbo setup.
Natural Aspirated 3.1liter L-engine is approaching that number nowadays.
>I was told lower compression is better for Turbos and if I go higher I
>would use less boost.
That's correct. For turbo (boost), you want lower compression. For Natural
Aspirated engine, you want high compression.
Weather turbo or natural aspirated, camshaft profile and the cylinder head
work is the single most important thing to consider in building an engine.
We can build crem de la crem, best in the world turbo or natural aspirated
head, if you are interested.
As for bottom end parts, I suppose you are seeking advice on the bottom end
setup?
For just 400hp setup, 3.0liter (w/ L28 crank & 89mm pistons) with our head
and our recommended camshaft, coupled with appropriate carburation/injection
and manifold & header should achieve that easily.
You want the top of the piston to be at par or slightly below the block
deck, (but not too much below the deck) and little adjustments can be done
with the metal gasket thickness (we can supply in 0.2mm increment). As for
pistons, shorter pin-height pistons is the way to go, my suggestion is 29mm
pin-height (38.1mm for stock pistons). Many people use dished pistons for
turbo setup, some use flat top pistons. Flat top pistons have much better
combustion efficiency than dish or dorm.
207.90 (block height) - L28 crank (39.5) + pistons (29mm) = 139.4mm.
We can supply 139.5mm chromoley rods or 138mm chromoley rods. Or if you use
32mm height pistons instead, you can use 136.7mm rods (and offset them if
needed), or use LD28 (41.5mm) + 136.7mm rods + 29m height pistons (0.7mm
below deck), etc etc etc. There are many many combinations we can do.
Having said all that, are you all fixated on a turbo engine? Natural
Aspirated L engine is very much fun, and N/A 320+hp engine is just as fast,
if not faster in 1/4mi than a 400hp turbo L-engine.
Eiji-