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fubar

How Much Boost Can A Standard Rb25det Neo Take

13 posts in this topic

Hey guys,

Got a rb25det neo in a r32 and was running 15psi for 2 years (mainly track and drift) and it loved it never failed me once! Im really impressed with Mr nissan, its my first one, i was a toyota fan before :rofl2:

Got a new turbo on the way and a nistune so i would like to up the boost a bit maybe 18psi mark depending on how the tune will go. I will make sure all the fuel and spark is sweet.

Just wonder what these motors can take daily? it can have some hard days so if it wont last long above 15psi i will leave it there.

Cheers

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Yeah 18 is probably the known max what people consider to be still reliable on stock rb25 motors wouldnt wana push it higher though but having said that its also in the tune a poor tune on 18 is dangerous so if its a good tune 18 should be fine.

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What Turbo?

is it 18psi on a T51R SPL

or a GT15?

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the boost is largely irrelevant its the KW that hurts them.

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well poor tune will kill them faster , boost/power is irrelevant to a degree ... talk to you tuner?? most won't talk for the sake of hearing their own voice :P

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Lol zebra

Yer what turbo? i ran 8psi on my GT3450 daily

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Tune boost and power all have some part to play in the reliability of an RB25. Tune is the most important. Turbo size does matter but I still wouldnt want to run much more than 20psi even if you have a small turbo.

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Cheers guyz,

yeah the lower the boost the better for the motor but just curios to how much they can take befor the head gasket goes or holes in pistons:) my old supra didn't take mush till the gasket went.

I've just high flowed my neo turbo from Stao at hypergear 52trim with a high pressure actuator. Is a good tune a nis tune from hyperdrive in perth or can any1 recommend a tuner in perth for rb motors?

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Cheers guyz,

yeah the lower the boost the better for the motor but just curios to how much they can take befor the head gasket goes or holes in pistons:) my old supra didn't take mush till the gasket went.

I've just high flowed my neo turbo from Stao at hypergear 52trim with a high pressure actuator. Is a good tune a nis tune from hyperdrive in perth or can any1 recommend a tuner in perth for rb motors?

The internals can cope with over 20psi easy as, they just cant handle a certain amount of power.

Ive heard you shouldn't run more than 17psi on factory head gasket, change that and your all good to go.

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andy at hyperdrive can sort it all out for you.

cylinder pressure is what kills head gaskets, too much boost with too much timing etc. all comes down to the tune

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The question should be, what boost will the turbo make the most efficient and most reliable power at.

Of course a hi-flow or aftermarket turbo can make any more than 20psi easily.

Considering the standard housings are used, 15-16psi should be the max you would want to run. Any more, and it just creates excess heat, which means more tendency to knock and possible loss of power at top end, especially if youre going to drift and track it.

Youll be happy with the 34 turbo anyway, should make 270-280 on 15-16 with good supporting mods and a good tune if its a good hi-flow.

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Hey guys,

What about standard pistons?

im about to get my rb25 tuned which has forged pistions and was looking to run 20psi with garrett 3076, bigger throttle body but a couple people have saide with standard cams and springs it wont flow it....

Anyone running standard cams and springs with 300kw for a long period of time?

cheers

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excessive heat, excessive detonation, increased temps, poor oil, excessive exhaust temps etc are what kills an engine

boost is usually seperate to these, but a higher driver and can influence what kills the motor

ie high boost, high intake temp, leads to detonation, leads to piston failure and ringlands toast etc

the state of tune and compression among many other things play a part in how long it can last, or how reliable it may, or may not be

one thing for sure

the more boost, the more stress, the more heat, the more likely to detonate, the more likely to fail

ie if you can run 14psi effeciently and make good power vs

run 18psi and ring its neck for an extra 11kw, stick with 14psi

be sure every psi extra you add you gain power and torque

otherwise its pointless and increases failure rate or rapidly reduces mean time between failure

ie dont run 14psi and have a nice sweet tune

and then just add in more boost to "hope" it makes more power

check and be sure, otherwise you might be adding more heat and risk for no gain, or in some cases, less gain from increased detonation and intake temps

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