Jump to content
SAU Community

FYI : RB25DET Injector Flow Rates

EnricoPalazzo
 Share

Recommended Posts

Sydneykid Grand Master

Sydneykid

Posted
Posted
But remember the more you raise the rail pressure and ram more fuel throught the injector you change the spray pattern

And you have to leave some headroom in the fuel pump for boost. :headspin:

Sydneykid Grand Master

Sydneykid

Posted
Posted
Around 45psi rail pressure.  its a trade off.  aftermarket inj. cost tons, raising the rail pressure costs F A.  If u had the coin to need 65psi rail pressure u would change the inj anyway.

And since most fuel pumps are rated at 73.5 psi, you would only have 8 psi left for boost. That's not much :wassup:

B-Man Grand Master

B-Man

Posted
Posted

How long will your fuel pump last if you fit a FPR - ie compared to if you didn't fit a FPR ??

A) The same as if you didn't fit the FPR ?

B) Less because you are labouring the Fuel Pump ??

c) More because of some unknown reason ??

I suspect (B)

4door_Sleeper Veteran

4door_Sleeper

Posted
Posted
And since most fuel pumps are rated at 73.5 psi, you would only have 8 psi left for boost.  That's not much :wassup:

To get that sort of power I assumed you would already be on boost. Surely an aftermarket rising rate regulator will allow you to maintain a slightly elevated fuel rail pressure and then rise it to 65psi by the time you are on full boost.

I don’t have a problem with using a RRR, but if you are pushing that type of power (and I am assuming you have replaced the turbo, fuel pump, computer, intercooler) then surely the cost of injectors is worthwhile even if it’s just insurance for your motor.

Sydneykid Grand Master

Sydneykid

Posted
Posted
How come I get 92-94% injector duty quite regularly with 0.85 bar and standard turbo?

 

One day it hit 100% when i wasn't looking but it seems to have these microsecond spikes like 65% when you've barely touched it.

Car is running rich?

Sydneykid Grand Master

Sydneykid

Posted
Posted
To get that sort of power I assumed you would already be on boost. Surely an aftermarket rising rate regulator will allow you to maintain a slightly elevated fuel rail pressure and then rise it to 65psi by the time you are on full boost.

Yep, that means full boost is 8.5 psi. :rolleyes:

Abo Bob Grand Master

Abo Bob

Posted
Posted
Car is running rich?
You should see my fuel bills! Jeez man. Weird thing is, at the track the exhaust goes brown like it's running lean.

I'm thinking of putting a 2nd hand SAFC in there till I can afford an emanage and a good tune. The ECU I have makes it run so smooth but I think it's just putting way too much fuel in.

INASNT Grand Master

INASNT

Posted
Posted
Magic1s GTS has 435rwhp on stock injectors and uprated pump,this is the most we have seen sofar on stockers and we have never had any problems at high fuel pressures.

We will fit a bigger pump and see how we go.

This power is in shootout mode.

I see around 80% duty cycle from my 550cc injectors with no FPR and Bosch 044 pump with around 312kw@wheels.

Sydneykid Grand Master

Sydneykid

Posted
Posted
I see around 80% duty cycle from my 550cc injectors with no FPR and Bosch 044 pump with around 312kw@wheels.

That's about right, I have seen around 565 to 570 cc's out of injectors rated at 550 cc's.

So 570 X 80% / 1.34 - 60 = ~300 rwkw

Your 312 rwkw is a pretty good effort. :)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      All I hear is ROADTRIP!
    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • wizlb
      Who has a Infiniti Q60, Q50 (V37)?

      By wizlb · Posted

      I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Kinkstaah
      Starting again

      By Kinkstaah · Posted

      Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
×
×
  • Create New...