I woudln't turbo it without changing the rods and pistons, injectors (maybe fuel pump) and ECU.
Yes you can turbo it but with the above mods you can get waaaaay more power reliably and without them it will most likely go bang. There is a guy on the forum with a rod out the block just recently.
I've also got an MR2 turbo and even the stock turbo rods and especially the pistons (which are waaay stronger than the altezza) are only good for 300 wheel horse or so. With mods there are plenty of 500+ wheel HP 3SGTE's around.
What you could do is buy another engine and put it on a stand and do the upgrades... then when its ready swap it over and sell your old motor for what you paid for the new one etc. That way you can still drive the car when your working on it.
Nathan
yes i know, i'm all so planing on changeing the injector, fuel pump, and im going with the e manege ultimate cuz i have and A/T, i wont good for the piston and rods mods cuz im there isnt a shop in my country that has done work on a beams 3s-ge engine, be sides the hks people said that turbo kit works with the factory compression
Yep it works with the pissweak amount of boost they run... the problem is its not that much more powerful than stock and hardly worth the effort... with lower compression you can turn the boost up and start to make some real safe power like 400hp (flywheel)
Also if it runs lean for any reason (overboost or fueling problem) it will destroy the motor. With forged internals it will survive some minor pinging.
Anyway in the end it's your car do with it what you like.
I've also read somewhere the toms 280T wasn't a stock engine turbo'd it had lower compression so either a decompression plate or different pistons. Makes sense toyota don't usually engineer grenades.
Nathan
u are so right, just came from speaking with one the most popular tuner in my country, he said all most the same has you nathan, he told me that the car will only handle 7psi of boost, and i went WTF, so scratch i wont go turbo any more, is to damn pricey i just would do some N/A mods and tray getting of it 260 oh 270 at the most