Upgrade Oil Pump

[naufal]

i had install these on my er34 and the piston rings gave up....

greddy t67 25g

turbo smart waste gate

hks fuel pump, rails and 680cc injectors

greddy bov type r

hks s-type intercooler

sard fuel regulators

hks twin power

tomei 2.0mm metal head gasket

greddy emanage

apexi n1 exhaust

greddy oil cooler

first i run at 7psi, after installing the head gasket to lower down the cr, i boost up to 14psi.. after some time.. kaboom.... piston ring gave up..

now i've got hks gtr 87mm piston kit and tomei con-rod and 1.5mm metal head gasket but then somebody told me that i need to change the oil pump.. any ideas...? does the rb25de oil pump not good enough? need to know before i put in the pistons...

top pic is rb25de oilpump and down is rb26dett oil pump