Hi,

Anyone know what injectors i will need to achieve say..... 350-400BHP with supporting mods.

Because im having my classic EJ20 re-built with forged internals etc.

 

There is a chart some where, but im sure 550 will cope upto the 420 mark i think.. correct me if im wrong someone??!!

 

550's will be fine as long as your not playing with mix's of ethanol(bio) and the like.

 

I'm told they would be all done by 400bhp, I don't quite know what that means in terms of duty cycle because if they were maxing then I wouldn't want to go there. When they're close to maxing the spray pattern becomes unreliable.
For my money I'f I'm close to 400 then I want my injectors at 80% D/C and for my newage that means 650 injectors
My STI pinks are at 85%DC running 350BHP (but have 10% methanol)

 

think about your future plans then you only need to buy your injectors once. i went for 740's

 

740's for me to

 

And the 740's can be limited down to 350-400 BHP yes?

 

yes joe it's done by the mapper, at least then that side of things is not anywhere near maxed out.

 

650's top out at 470bhp

 

650's are New-age fitment as 740's are classic fitment

 

550cc injectors on STD fuel pressure wont see 400bhp, 650cc > would be better leaving room for a safer map if needed.