Stock turbo limits?
 

What kind of PSI od bars of boost can the stock RBs put out?
RN20 is?
RB25 is?
RB26 is?

Thanks.

info for RB26DETT; GTR (ceramic bladed exhaust/ steel or plastic compressor):

R33 stocks can go to 0.85 bar, R34 to 1.15 bar( recommended maximum). i have heard of stock R33's running 1.2 bar.

the R34 unit is a "roller bearing core," the R33 a "270 degree bearing core."

the R34 turbo is regarded as a better flowing unit, with a higher A/R on one side (cannot remember which).

either turbo with a steel turbine upgrade can run to 1.2 bar.

seems that the quicker spool-up is an R34 unit upgraded to titanium turbines, which spool up A LOT quicker, and can run even higher boost, but i am not sure just how far you can go.

I,ve been running 18psi for the last 18 months without problems but i have been lucky as most fail at this boost

On what motor? 25 or 26?

26

I've heard 1.0 bar (14.5psi) is the recommended maximum for ceramic units, with 1.1 bar (16psi) being the absolute maximum. Still running stock boost on an RB25DET myself.

I believe some limited edition GTRs have turbos with all steel internals (N1s, V-Spec IIs, Nur Specs ???), these can be ran up to about 1.4-1.5 bar with pump gas.

R33 GT-R max 0.85 bar (slightly under 12psi).

R34 GT-R max 1.15 bar (slightly over 16psi).

Both figures as recommended by Nissan. I know of people running 1.2 on stock R33 units, although most seem to consider 1.0 the best compromise.

Steel internal R33 turbos can be run at 1.3 or 1.4 bar, although technically their efficiency peaks at about 1.3 bar.

Roller bearing units offer a faster spool up time.

Think the limit on R33 GTS 25t is 0.8bar.

dont know about non gtr's but as I understand it

r32 gtr standard has ceramic wheels which if run over 1 bar have a higher risk of breaking and possibly causing engine damage
R33 the same - never heard of them being limited to 0.85 bar. The R32 and R33 turbos and engine are the same.

R34 normal 1.15 / 1.2 bar (not sure which) as these can take slightly higher load due to having ball bearing cores which = better load distrubtion on the wheels / shafts.

The only special edition turbos that I thought were uprated with steel internals were the N1 turbos. These max out at 1.4bar. Above this they only create extra heat - no extra power.

The R32 N1's have a 270 degree thrust bearing.
The R33 N1's have a 360 degree thrust bearing
The R34 N1's have a ball bearing core

Think thats right. I am sure someone will fly in there and correct me if not.

cheers
martin

R33 N1s have 360 degree

R32&R33 gtr= 0.9 BAR or about 14psi. Above this you wont make any more power and the effeciency will suffer and the turbos will only create more temperature above 0.9 bar. Also if you run 1 bar or above in about 2 weeks the ceramic exhaust wheels will half disintergrate and the reamaining part of the wheel will go exploring and end up just before the catalytic converter.
RB20=about 13psi=. Same thing will happen as gtr ceramic turbines if you excede this limit.
RB25= about same pressure as the rb20 turbines but you know these wont fail from the ceramic turbine wheels.
R34 spec units can take up to 1.5 bar

what model turbos are they?
are there any new turbos that have the same flange...
like would a pair of gt-30rs sit on there?