Jump to content
SAU Community

Tuning For Bigger Injectors

ossie_21

By ossie_21,
in Engines & Forced Induction

 Share

Recommended Posts

ossie_21 Grand Master

ossie_21

Posted
Posted

Hey all, just a quick question in regards to some tuning. I have an r33 with an engine being built as we speak, and it should be bedded in by the end of the month. In around a couple of months time I am then going to be looking at some bigger injectors to make over the 400rwhp mark, and then hope some shit don't break :)

So the question is this, with an already tuned ECU, what is the go for tuning for bigger injectors? Is it a "simple" tune & relatively cheap to do or does it still go a bit pricy? I've heard a couple of different things about it so I'm asking if anyone could tell me from first hand experience....Most people do the ecu & upgrade injectors at the same time but it's hard to tell the dyno time/cost for injectors only, searching provided nothing for me.

While I'm here, with a GT30R (500hp) with 45mm external gate, what size injectors would be the most ideal for me? Daily the car will be driven about 40kms, plus whatever on the weekends (or my days off because I will end up working them again soon). Does bigger injectors also mean more fuel consumption, or is that down to the boost level I run at? Looking at keeping it lower for the daily driving but then of course putting it up at the appropriate times.....

Cheers, any help appreciated!! :(

Link to comment
https://www.sau.com.au/forums/topic/137477-tuning-for-bigger-injectors/
Share on other sites
CEF11E Veteran

CEF11E

Posted
Posted

If you are after 400 rwhp I would be going for 600cc.

If you have a power FC you already have toyr fuel and timing maps done. put the injectors in and change the size /flowrate/latency and dyno it and you are done.

If you have a remapped stock ECU you change the

K value to suit the larger injectors

reference the void blast off time. then you need to recalc your boost table.

Can be a lot of fu$%ing around on a stock ECU if you do it properly.

I am assuming u have a power fc tho?

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Nismo 555cc injectors for the RB25DET.

Direct bolt in affair, not stuffing around. I wouldnt be using anything else.

Well the stock injectors are going to be maxed around 220-250rwkw. So you wont be able to do a full tune to begin with.

It wont be "as much" as a from scratch tune, but it wont be a 20min adjustment either.

Should be around 3/4 of the price... Most full tunes are around $500, i'd expect to pay around $400 give or take if i changed injectors and needed a reasonable update to the tune

As for fuel consumption, that is governed by one thing and only one thing.

Your right foot

ossie_21 Grand Master

ossie_21

Posted
  • Author
Posted
Nismo 555cc injectors for the RB25DET.

Direct bolt in affair, not stuffing around. I wouldnt be using anything else.

Well the stock injectors are going to be maxed around 220-250rwkw. So you wont be able to do a full tune to begin with.

It wont be "as much" as a from scratch tune, but it wont be a 20min adjustment either.

Should be around 3/4 of the price... Most full tunes are around $500, i'd expect to pay around $400 give or take if i changed injectors and needed a reasonable update to the tune

As for fuel consumption, that is governed by one thing and only one thing.

Your right foot

Yeah, my right foot seems to handle it quite well, the most I've driven my car was freeway to and from work, so cruising was easy. But with what it will be for now I'll have to wait & see :D

Sorry the thing I didn't mention was that my ecu is a wolf ecu, and the tuner I will be using prefers these over anything else. They seem to get more out of the stock injectors than a pfc can, because my power level was just over 260rwkw, and there are a few similar cars (standard rb25's) that were getting more power too!

But thanks to both of you, also got a helpful pm too so that will be something to look forward to! Cheers, Nathan

Cubes Grand Master

Cubes

Posted
Posted

Out of curiosity....

Why or more importantly how did the old motor pop?

You can make plenty of power on the std injectors.. ramp that fuel pressure up and thats it. Not too good for reliability though.

I've known 1 rb25 to push 258rwkw on std injectors and it popped a little while after. Did its ring lands. Suprise suprise on std injectors. :D

ossie_21 Grand Master

ossie_21

Posted
  • Author
Posted

It was just piston no. 1 that went, thats why when he took the engine apart he was suprised at how well everything looked except for that one which has a nice hole in it :)

Haven't seen it as yet but will see it & find out next week, who knows maybe injector failure was the reason!! Boost will be down until the injectors anyway because I will be bedding the engine in & by the end of that it will be ready. For my 21st the hint hint to my mum is for the injectors :O

Cubes Grand Master

Cubes

Posted
Posted

Hrmm a hole you say....

Ahh well live and learn. Buy injectors to suit the power level and you will be looking at and enjoying a reliable motor providing the engine builder and tuner know what they are doing. :)

As R31Nismoid said... 550cc injectors will suit your power level.

GeeTR Grand Master

GeeTR

Posted
Posted

Howdy,

Are we talking about the spreading of a cylinders fuel requirements over two injector openings? Instead of opening once on intake stroke, it opens twice in the 4 stroke period, two half openings, effectively squirting fuel on the back of the closed intake valves.

This was done with older OEM injected engines, plus is a method used by thems today with cheaper AM ECU's, as you only need half the mosfet's or "injector drivers"

I dont quiet understand its relation to the Wolf though, pause on the pop corn and give us a hint :whistling:

- Michael

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

    • AdiR34
      Did tie rods. Steering now not "springing" back.

      By AdiR34 · Posted

      Yep, there's a very minor drift left that happens a few seconds after letting go of the steering wheel, but not enough to bother me. Enjoying the car still!
    • Keeper
      S A U N S W Club Membership

      By Keeper · Posted

      Got you mate. Check your email!
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      I see you've never had to push start your own car... You could save some weight right now...
    • niZmO_Man
      For Sale 2003 Nissan Skyline V35 GT350 Premium

      By niZmO_Man · Posted

      You need to put location and price
    • Murray_Calavera
      Steps to DIY sanding car back ready for respray....

      By Murray_Calavera · Posted

      Sounds good.  I don't 100% understand what your getting at here. When you say, "I keep seeing YouTube videos where people have new paint and primer land on the old clearcoat that isn't even dulled down" do you mean this - there is a panel with factory paint, without any prep work, they paint the entire panel with primer, then colour then clear?  If that's what you mean, sure it will "stick" for a year, 2 years, maybe 3 years? Who knows. But at some stage it will flake off and when it does it's going to come off in huge chunks and look horrific.  Of course read your technical data sheet for your paint, but generally speaking, you can apply primer to a scuffed/prepped clear coat. Generally speaking, I wouldn't do this. I would scuff/prep the clear and then lay colour then clear. Adding the primer to these steps just adds cost and time. It will stick to the clear coat provided it has been appropriately scuffed/prepped first.  When you say, "but the new paint is landing on the old clearcoat" I am imagining someone not masking up the car and just letting overspray go wherever it wants. Surely this isn't what you mean?  So I'll assume the following scenario - there is a small scratch. The person manages to somehow fill the scratch and now has a perfectly flat surface. They then spray colour and clear over this small masked off section of the car. Is this what you mean? If this is the case, yes the new paint will eventually flake off in X number of years time.  The easy solution is to scuff/prep all of the paint that hasn't been masked off in the repair area then lay the paint.  So you want to prep the surface, lay primer, then lay filler, then lay primer, then colour, then clear?  Life seems so much simpler if you prep, fill, primer, colour then clear.  There are very few reasons to go to bare metal. Chasing rust is a good example of why you'd go to bare metal.  A simple dent, there is no way in hell I'm going to bare metal for that repair. I've got enough on my plate without creating extra work for myself lol. 
×
×
  • Create New...