Article: How much PSI will my engine hold? A common newb question...

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There is not specific answer to "how much PSI will my engine handle"

14psi from a T25 turbo is far different from 14 psi of a T4 turbo.

Sure the PSI is the same but the CFM (volume of air) is different. The bigger the tubo the more amount of air it will push.

The correct question would be "how much horsepower can I make with my stock engine".

We will refer to the Honda B series today. The LS/GSR/B16. This excludes the B20 and ITR because they vary a bit from the more common honda engines. The ITR has a high compression ratio that suck for boost. The b20 has really thin stock sleeves because it's the only honda B series that has an 84mm bore.

The ls/b16/gsr engines can all handle @ 300 whp if they are in good condition.

Idealy the bigger the turbo you use the less PSI you have to run to make that much power. The smaller the turbo you have the more psi you will need to make that number. The bigger the turbo the longer it will take to make power. The smaller the turbo the quicker it will start making power but if you make it too small it will stop making power too early.

your turbo of choice will vary depeding on what you want to use it for. A street car wants to make power quickly but not too much power where it's not usable on the street. It's important to have alot of midrange power for a street car. A t3/t4 .57 trim is ideal for most street cars

a drag car or rally car will want more top end power since it will be in the upper rpms the entire time they are using the car. Here a t4 turbo may be ideal fo you.

an auto x car does not see very high speeds, here you want to make power very quickly in the low to mid range and you want to do it without too much torque. Too much torque out of a FWD and you will loose control everytime you start to accelerate out of a turn.

The LS engine performs a bit differently than the GSR or B16 engines. It does not have VTEC. It also does not rev as high. With the LS you will only be reving to @6K.

With the GSR or b16 you will be reving up to 8K. With the GSR or b16 you will probably want a turbo that will make power a bit longer than the LS.

The LS also has lower compression that the b16 and GSR making it a little more ideal for boosting.

However, as with any engine, the more efficient an engine is before adding a turbo, the more power it will make after it's turbo'd.

The conditon of the engine and quality of the tune will determine just how long the engine will last.

The weakest part of a honda engine are the cast internals.

Honda cast internals were not designed for the temperatures that are caused by a turbo. The excessive heat causes heat expansion.

Hondas also have floating sleeves, another weak point of the honda engine but stock sleeves have been successful on over 600 whp engines. It's all in the tune. The idea is to keep cylinder pressure down and tune her safely so there is not pre detonation.