Hey MR2 Australia! First post! Now that I've got that out of my system onto the things that matte... I've bought myself a 1993 (n/a gen 2) sw20 with dreams of building a time attack race dedicated car.

First things first, 3VZFE, from what I've read this is probably one of the better V6s to go with as it's cheaper than the GR's, doesn't have the knock sensor issues that are common with the 1MZ. And due to the lower compression ratio will likely be more suited to forced induction in the future. Ill be looking at mating it to the 153 turbo box for the added strength, I believe there will need to be a flywheel swap or modification to do this, any clues?
I'll also be going to a stand alone Ecu eventually but for the short term would i be better off getting an ecu out of say an ES300 and running that?

Ill update more later today.
Alistair, Victoria

Welcome to the forum :) I hope you enjoy your MR2.
Start a showroom thread for us to admire your car, and it's a good way to document your progress.
I can't help with V6 info though, I'm a BEAMS guy lol
There's plenty of guys here that will help with their experience and knowledge.

If your going aftermarket ECU, you might as well go 1MZ as the "Knock sensor issues" is moot.

Interesting. I'll look into that. How strong are the internals of the MZ? Correct me if I'm wrong but they have weaker conrods don't they? Also would the higher compression ratio strangle future boosting? The 3VZ runs a 9.6 to the 1MZ 10.1

The weak point in the 1MZ is the pistons, the ring lands tend to fail from detonation. They start failing over 300RWHP, this was quickly found by the work of Tristan @ WTFAuto. The pistons are easily replaced with off the shelf forged 5SGTE 87.5mm pistons (CP make them) and require 1mm removed from the crown of the piston (as the pistons deck height is different).
 
The rods don't become an issue till your around 500+RWHP. Once again, as found out by WTFAuto when they bent a few over this. You can spend $$$$ and buy Eagle 1MZ forged rods or your can buy 22R forged rods and machine 3mm from the width of the big end.
 
Now a lot of people have a "bacon and egg mc whinge" about the 1MZ pistons and rods being an issue and there for go with a 3VZ, but if your making 300+RWHP or aiming to build an all out track car, you should already be looking into forged components. In which case, the point is moot.
 
If you have the money, buy a 2GR.
If you have a budget, buy a 1MZ.
If you have a boat, buy a 3VZ. (for an anchor)

I put a 3vzfe into mine and im pretty happy. 

3sgte + e153 is also a boat anchor by that comparison.
 
My 3vzfe + s54 is lighter than a standard turbo mr2.
 
2gr is WAAAY lighter and 1mzfe is lighter than 3vzfe. But to say a 3vzfe is a boat anchor is a bit of an exageration :P

Whats the power output of the 3vz tho compared to a 3sgte. And easy to increase the power out of a 3sgte than a 3vz. Hence boat anchor....lol