I'm thinking of buying a 200zr (z31 300zx shell with an RB20DET) and so I read up on the RB20 engines; found out that ZR's come with the red top version.

What I wanted to know is what exactly the difference between NICS and ECCS injection systems is and what can be done to get the power of a silver top RB20 without getting a whole new engine.

(Might as well stick an RB25 in if I'm going for a whole new engine)

Also any other ideas on some relativley simple mods that would be worth doiing on a budget to an RB20DET?

If its a NICS bin it, the head is terrible, turbo is too small, inlet is no good and computer sucks and has a terrible tune. If its a redtop ECCS then with a remap it will be almost as good as a silvertop, eg I'm getting 151rwkw out of mine with just exhaust, fmic, and remap. I've seen people struggle to make 130 with a rb25 turbo on a nics.

^ same same

had a ECCS late model 31 at work put a silvertop r32 turbo on it and it transformed the motor from a laggy heap of junk to almost the same as a

silvertop rb20 i.e alot better

My RB20 NICS made 160rwkw with a RB25 turbo, chipped ecu, EBC etc.... but my motor is in perfect health unlike most NICS which are usually buggered.

You can just change the turbo to a 25 unit, but without an ecu upgrade you won't see a big improvement due to low boost cut and poor fuel map.

I'd suggest just keep the car standard then save for a RB25 like you said.