I am planning on turbocharging my box, but the 1NZ sports a 10.5:1 compression ratio, how can I overcome this without buying new pistons?

Don't run more than 6 or 7 psi, use 93 octane gas, maybe a thicker head gasket.

Block saver

the money you will spend on the turbo kit will be very much
imo if you are going to do it do it right change whatever you need if its 500 extra when youre already at 4-5k thats a non issue you will benefit more and be glad you spent the extra$$

I would read this page on EL Prototypes experience with the 1NZ:

http://elprototypes.com/1nz%20turbo.htm

Their site seems to be down right now, but here's a couple of relevant quotes:


It responds to boost quite nicely with a properly sized turbo. But its downfalls are the internals and its engine management.
Lets touch on the internals. First and foremost are the rods. Although quite strong for their size, they are designed for normal aspiration only. A half point higher in compression is about all they can handle daily without failure. Once boost is added to the equation, it becomes Russian roulette as to when they will let loose. You may last eight months with 50,000 miles or blow it the first pass down the street; there are no warning signs.

These engines have the crankshaft offset 12mm to the thrust side of the cylinder bore centerline. This reduces the side force generated at maximum compression, for reduced friction and improved fuel economy. Toyota calculates the offset crankshaft configuration reduces fuel consumption by between one and three percent. Unfortunately, this throws the angle of the rod way out on its upward travel causing the rod to just give up under boost and snap. If there is any detonation or pre-ignition this breakage will occur at an accelerated rate.

Not trying to be a wet blanket, just making sure people get as much info as possible before taking this risk...

Yeah surprisingly the high comp. ratio is by no means the problem this motor has with boost.