Skyline Owners Forum banner

Max Power on stock injectors

10K views 26 replies 11 participants last post by  Jsx 
#1 ·
was just wondering from others experience what the maximum horsepower i can get out of the stock rb25 injectors. whp if possible.
 
#4 ·
they shouldn't leak - if they do you've fitted them incorrectly. Did you use new seals and did you grease them on insertion? (ooo err!)

You can squeeze more out of them by upping the fuel pressure but this needs to be done very carefully with good mapping required.
 
#5 ·
i am using an emanage ultimate to tune it but i currently have no fuel regulator to up the pressure. i think it was leaking becasue of the rail. i got another rail from a friend and it seems to be working just fine now with the stocks but i really dont want to mess with it in fear that they are going to leak again. the leak was so bad that it would lock the motor up and i would have to vacuum the fuel out of the chambers throught the spark plug hole. really dont want that happening anymore so i hope that you can understand my caution.
 
#6 ·
Hydraulic lock eh - cool :D

If they're correctly installed you really shouldn't have an issue. If you really want to leave as is, as I say, a decent adjustable FPR to raise fuel pressure a few psi should squeeze a little more out.

Either that or the cheap pikey route, wack a socket down on top of the std FPR ;) (not guaranteed and could damage things which is bad mmmkay)
 
#7 ·
the problem with the other rail was that the person who had it before painted it and that it was chipping really bad so i had my friend sand blast it clean and i think that it made the inside of the rail real rough and that caused the o-rings to leak real bad. maybe with the rail i have now it should be fine. just dont want to mess it up if its running good right now. also the caps on the injectors that we bought all came off the end of the injector so i would have to put them in with just the o-ring and no caps at the end to keep them in there right.
 
#12 ·
To get max out of stock injectors, would it be any advantage to replace AFM with a Z32 or Q45.
or

Will injectors give out before the AFM?

Mmmmmmmmmmmmmmm interesting!
 
#15 ·
no, with the 800cc injectors i wanted 500+whp out of it but with the stockers i want just 350whp or around that. i am thinking about attempting to put the 800's in again but i need new oring's for them. the ones they came with got torn up by the old rail. maybe i will bring them to get flow tested and have the guy put new rings and caps while i am at it. they are direct drop in. thats why i ordered them.
 
#16 ·
mine were maxing out at around 320, got some top feed 550s in there now, correct impedence mind,
 
#21 ·
i am definetly going top feed but just wanted to see what i can get out of the stockers for now. top feed is really expensive so its kind of out of the question for at least a few more months. unless any of you have a setup for cheap that you are willing to get rid of. i would really appreciate it. no less the 550cc though thanks a lot.
 
#22 ·
standard fuel injectors

im running 380bhp on standard injectors & afm but my injectors are on there limit i must admit but it has been correctly mapped im using a apexi pfc.
now looking at replacing the injectors to 550cc & z32 afm so i should see a nice increase in bhp.
HOPEFULLY ! LOL
 
#26 ·
arry im running standard fuel pressure as i have no uprated pressure regulator & hi5 im not sure what power is at the wheels ? on my dyno sheet it reads 380bhp & nearly as much torque how can i find out or how is it worked out ? & the car was mapped by james & innovate brands hatch
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top