I was currently building up an a15 carb-based (eventually efi engine) - still need to order some bits so can swap it out to suit turbo application

I now have the opportunity to buy an oval port efi turbo setup.. just wondering if it would be better suited on the a15 or a12 with some mods?

it's a t2 turbo

Nearly everything is better suited to the A15 instead of A12 -- A15 has more HP and more torque. But more importantly, most A15 come with oval port head, Very few A12s do. Also consider that most A15 has slightly lower compression than most A12. And stock A15 is ready for 15 psi boost (rods, pistons and head gasket are already capable)

So would there be anything in setting up the a15 I could do to help prepare it to run a turbo.application? Seeing as it's back from the engine builder after being.cleaned up and inspected

Add an oil return line to the oil sump (for the turbo oil feed)

There is a lot you can do, but it's all quite unnecessary for an engine kept below 6000 rpm. As long as your A15 has been rebuilt to Datsun specs, it's all good

The most important thing will be the EFI tuning. Is critical to keep the timing below detonation and keep a/f ratio from going lean, either on of which will destroy the most strengthened engine and can destroy rods, pistons, valves or head gaskets. Keep it all under control and a stock A15 can put out 120 hp with all stock internals

Thanks David! I guess the main thing will be a good tune and ECU.. With the turbo oil return do you have any pics of.someone who has done that?

Im pretty sure the A12 pistons have an advantage in one department over the A15 slugs
in that the rings are thicker like 2mm or something like 0.5mm thicker

The E15 pistons are also a straight fit if you bush your rods that give you a very
strong piston made for boost from factory.

If you go do some research the suzuki vitara pistons take 24psi when fitted in
Honda D16 turbo engines and have been it on anything needing 75mm bores for boost.

Most A series are almost made for boost as stock engines straight from factory
they are over-engineered in most cases no need for aftermarket rods etc.

> With the turbo oil return do you have any pics of.someone who has done that?

Just drill a hole in the side of the sump, and tighten this fitting: http://ebay.com/bhp/turbo-oil-pan-drain
It's low pressure so no need for the threaded types though they look schmick