Max Psi A Stock Rb25 Can Take

[hayden49]

hey all,

just wondering what the max boost an unopened rb25 can take.

got a list of mods here i want to do when i finally purchase a car and it includes a t35r.

how high could i go before id have to rebuild with stronger internals?

cheers

[GiJOr33]

well it depends what other support mods are on the car, fuel pumps injectors, intercoolers etc. My car blew some ring lands at 1.1bar and that´s with a HKS GT3040, ARC fmic, stock injectors and engine management. Other people have done 1.3 bar, other less than me. You just have to mod the car the way you want, put it on the dyno and tune it to the max it will handle.

Andy

[hayden49]

cheers mate,

i have a huge list of other supporting mods that ill do way before that, kinda a long term project.

cheers

[Craved]

well you cant say a certain boost pressure is what an engine can take..

difference cams can affect the compression ratio hence allowing you to run more boost.

the main thing that will hurt the engine is the tune, not boost.

also remember that each turbo can flow different rates at each level of psi..

for example : HKS 2535 at 18 psi tops out at 250rwkw where as a HKS GT3040 at 18 psi is pushing 300rwkw..

both these engines tuned at the same place, sam cam specs injector sizes and mgmt ECU..

[paulr33]

craved is spot on here. most people think boost dictates how much power a car makes, that is not true at all. a car tyre at 30psi and a truck tyre at 30psi. both have the same pressure (or boost) but both have completely different amounts or air in them. airflow makes power. so its true that a gt2835 at 9psi may be fine but a gt42 at 9psi may not, as the gt42 will flow a stackload more air, maxing out injectors and so on...

[R33S2]

Sydneykid did an excellent post about this topic, (where? I dont know) he went on to explain how removing casting roughness in the manifolds and how intercooler and piping size all effect the final outcome.

airflow makes power.

Your question should be "How many KW can I safely squeeze out of the RB25" and the answer is around 250 rwkw, some have died before this and other have gone past it.