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Max Engine BHP before breaking?

Featured Replies

I am planning on doing extensive mods to my 2011 WRX STi but I dunno if I should rebuild the engine to handle the new hoursepower and I am planning on getting it remapped


If you plan on changing the turbo your basicly over the limit of the engine. mid 300's is about as good as it gets without playing roulet with it.

  • Author
6 hours ago, Tidgy said:

If you plan on changing the turbo your basicly over the limit of the engine. mid 300's is about as good as it gets without playing roulet with it.

 What do you mean roulet? As in pretty much hoping your engine doesn’t kill its self?

  • Author
30 minutes ago, Tidgy said:

yeah, afraid so, the standard 2.5 isnt great and wont take much more than 350ish before it's at high risk of failure :(

So should I first buy forged pistons and the whole set or just do a engine swap?


3 minutes ago, WRXLover said:

So should I first buy forged pistons and the whole set or just do a engine swap?

depends what your plans are and what budget tbh. engine rebuild is going to be 4-5k at least, but if you plan to aim for 500bhp then will be more than that plus a whole heap of supporting mods.

The 2.5 weakness is it doesn't have forged pistons so they are known to break ringlands and the headgaskets have a nasty habit of failing. It seems to be pot luck whether they fail or not.

  • Author
13 minutes ago, Tidgy said:

depends what your plans are and what budget tbh. engine rebuild is going to be 4-5k at least, but if you plan to aim for 500bhp then will be more than that plus a whole heap of supporting mods.

The 2.5 weakness is it doesn't have forged pistons so they are known to break ringlands and the headgaskets have a nasty habit of failing. It seems to be pot luck whether they fail or not.

 For the budget I am planning on saving for the full engine rebuild and then slowly adding mods during a 4-5 year period

so the budget and be tangeable 

not huge amounts you can do untill the main engine is sorted as far as power mods go :( decat and a map should see 330-340 and thats about your lot.

Set your budget for the engine (then add 10% contingency). Look at forged internals, replacing the crank bearings and upgrade the engine bolts. Consider replacing the oil pickup with a reinforced item and also fit a sump baffle  - that way you reduce the risk of oil starvation lunching your engine.

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