How much stronger is a standard 2005 jdm sti v9 2.0 spec C engine compared to normal sti ones,and what would need changing to be reliable at @475bhp?

 

By 2005 the short motor specs are virtually the same, Heads and cams are better on the spec-c though, Are you seriously asking if a motor that came with 300 bhp will still be reliable with another 50% power put through it?

Usually good for 450 as a rule of thumb but they can take more how much more you will only find out when it breaks, There are no safe/reliable figures as soon as you start modding, Is more how much you want to push it being safe in the knowledge it could go pop at anytime

 

Thats an quite an accurate figure you are trying to achieve isnt it, 475bhp?

 

The JDM engines have cast pistons fitted in some models (not alot of People know this) But ive had a few engines in for rebuilds and the pistons are identical to the new age STI type but cast, they do have nitrided cranks though??
I'm not sure which they were fitted to though?
Oh, by the way they needed a rebuild because they had melted the pistons!!

 

JDM Blob onwards as far as I know were all hypereurotic cast pistons, with the spec-c having the nitrated crank...not sure if the standard Sti had the same, A very similar spec to the UK MY05....but the japs had it 2 years prior to us.....I think

 

They nearly all have the hypereurotic (HF marking) type, but there are some fitted with a std WRX type cast piston, although it looks the same as an STI piston on the crown. I can't recall which engine its in, It could be the spec C?

 

You learn something new everyday....I'll go and whip one out of my block and take a pic, back in 5 mins,