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As what skyzerr33 said:)

Safely, with stock cooler, 10psi, with fmic 12 psi. Fuel cut is usually about 12 psi, so around .8bar.

Some cars seem to do ok on 1bar, some die a horrible death - depends on the health of the turbo????

With the stock cooler there is a pretty large pressure drop above 6000rpm, and boost pressure is measured at the plenum - so thus the difference in safe boost.

When you guys refer to max boost, do you mean consistently running that pressure. I have a S2 R33 and usually try and keep it around 10psi. However, I have been known to wind it up a touch and on a cold night have surpassed my 12.5psi warning on my EBC and hit 13.3psi but only for a second. Is this going to ruin my turbo in the same way? Or is it only when sustaining that boost. I literally heard the EBC alarm go off and lifted my foot.

It does seem that some people get away with it for a while - others dont. You turn up the boost it MAY cause problems - keep it down and you should have a turbo that last a while - choices:)

If you have a stock cooler, I 'think' (cant remeber exactly - anyone confirm?) its like a 7+psi pressure drop above 6000rpm -so if you are boosting to 12psi, the turbo is actually pumping 19+ (if the figure above is correct).

The big problem is the ceramic exhaust wheel, which is fragile - the compressor wheel places more load on the turbine wheel as the boost increasesie the compressor wheel has to work harder, the turbine wheel has to turn the compressor wheel - there for the load on the turbine wheel is incresed. When the air is colder, the air is denser, so it may even be worse in theory. This is how it has been explained to me anyhows.

10psi does just fine with the standard turbo. Most people running mid to low 13's use 10psi with the stock turbo, why push it further all you do is create more heat than power and shorten it's life.

Steve,

Last time I tested boost before and after the stock intercooler there was a 2psi or less drop even at 12psi.

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