skyline turbo issues

[sparra04]

quick update
fitted bov yesterday
went for a spin and boost was hitting 14psi, before cutting out
came home immediately and removed mbc, it was wound right out at MIN boost
boost now peaks at 7psi, car hesitates like its starving for fuel, but doesn't cut out anymore
we are on the right track
I will fit fuel pump sarvie and have a look at whats wrong with mbc
a safe boost level is about 9 psi for the rb 25 I believe ?
cheers

 

[Old.Tony]

Standard is 7 psi but the boost solenoid causes the wastegate to open during low rpm to limit the boost to 5 psi. The ceramic fins of the turbine (exhaust side) can only tolerate pushing the impeller to produce 11-13psi before they are destroyed. Supposedly the stock turbo comes apart at 14psi. Some people have been shipping the turbos off to get the turbine fins replaced with steel, but it seems a reasonable replacement (no mods required) is a GT2540 which can reliably produce boost up to 18-20psi.

 

[navaranewb]

quick update
fitted bov yesterday
went for a spin and boost was hitting 14psi, before cutting out
came home immediately and removed mbc, it was wound right out at MIN boost
boost now peaks at 7psi, car hesitates like its starving for fuel, but doesn't cut out anymore
we are on the right track
I will fit fuel pump sarvie and have a look at whats wrong with mbc
a safe boost level is about 9 psi for the rb 25 I believe ?
cheers

standard turbo is good for 12psi. Its not the boost that kills them its the heat that is produced. If you have FMIC and Turbo back zaust you will be fine at 12psi all day long

as for the hesitation i would start looking at spark side of this including the igniter (silver square on top of the coil cover at the back)

 

[sparra04]

Its a series 2 so it has a differant coil pack setup, no igniter I believe
A fmic is on the list
already has a tback zorst
so 10psi is fine ?

 

[navaranewb]

Its a series 2 so it has a differant coil pack setup, no igniter I believe
A fmic is on the list
already has a tback zorst
so 10psi is fine ?

series 2 has igniter

10psi is good. Leave it there as once you put a FMIC on it will up the boost to about 12ish