Originally Posted by kitabel

This is a 2JZ-GE VVTi?
Not responding to your question directly, but in practical terms there's nothing you can do to nearly double the stock 225 horsepower without spending far more money than simply installing an LSX engine.

The usual paths to NA power:
1. more displacement - yes, there's a 3.4 liter stroker crank, it's about $3,000 plus the cost of rods and pistons plus machining and balancing. No, it will

not add power in direct proportion to the displacement change (3.4 / 3.0 = +13%), it's what you do when you've done everything else and you still have money left.
2. higher compression - perhaps another full point can be added and still use pump gas with new piston, $600 + bore & hone
3. more radical camshaft - definitely provides more power, generally at higher RPM, cams cost about $1,000 + install, valve springs etc.
4. bigger valves - small improvement at higher RPM
5. porting - same
6. larger TB, bigger plenum - more power at higher RPM
7. tuned exhaust - perhaps 10% more power, $1,500 including street hookup
8. dyno tune - my guy gets $100 an hour
9. larger fuel pump
10. larger injectors
You'll also need a LSD, transmission upgrade, bigger ATF cooler.
Is there a known-to-work "recipe" (shopping list + machine shop instructions) for such an engine, that you can duplicate and get the same results? perhaps, but not TIKO. You can buy a built engine from a shop, but $$$$.

All of these might, if carefully chosen and professionally installed, then dyno tuned may reach 350 HP (that's over 100 HP per liter - Ferrari territory), and easily cost $20,000.
Above that it's pretty much rocket science

Originally Posted by kitabel

I see you have found nothing of value in my remarks. If I may summarize: you can't get 350-400 hp by tuning a 225 hp engine, and bigger injectors don't add any power unless the duty cycle = 100%.
So, you're asking what injector size is needed to accommodate mods that you have not yet identified?
The only possible answer: bigger than you have now.