Ive done abit of a backyard DP injection setup on my 2jz. Ive got 6x240cc DP injectors and 1x300cc pre turbo injectors. On 23psi my fuel flow is around 60% or 3600cc ( ID1000's ) so my injection rate is about 49% without missfire ( 50/50 by volume ).
To be noted also my injectors only see approx 40psi so atomization isnt great but the valve is also closed for some time during the cycle so the water/meth and fuel will pool a little anyways. Ive also ran less pressure ( 20psi ) for less flow without issues.
Heres a little video of it on 16psi and approx 1300cc ( 20psi injection pressure ) 60/40 water/meth. Going by the weight and mph its making around 530hp at the flywheel. Have since dropped the compression and 9.2:1 and put stock cams back in it, will see how it goes.....
https://www.youtube.com/watch?v=8gjifYRPYsc
Cheers for a good read and actual results