Jump to content
SAU Community

Recommended Posts

Hi all, going to upgrade my standard 33 s1 rb25 fuel system. looking at a walbro 255, tomei 740cc side feeds and a turbo smart regulator. from what i can gather those are all close to direct fit replacements. is it that easy? are there any major issues i will come across that im sure someone else would have already found? any help would be great

Link to comment
https://www.sau.com.au/forums/topic/403666-rb25-fuel-system-upgrade/
Share on other sites

Do as was mentioned above, pump (hard wired for alternator voltage) and injectors.

You probably won't need 740's though, unless you are thinking this turbo isn't going to be the last/biggest one you get

In saying that Mitch i made the mistake of buying 550's and then had to buy 1000's later for E85, bigger isnt always a bad thing and the prices are similar, as long as they are decent injectors go nuts :)

In saying that Mitch i made the mistake of buying 550's and then had to buy 1000's later for E85, bigger isnt always a bad thing and the prices are similar, as long as they are decent injectors go nuts :)

By all means get the bigger injectors if planning to go e85 or get a bigger turbo down the track, as there is no difference in price really. But if intending to leave it at the highflow on 98 then 555's will do the job as well.

In retrospect i would have gone 740's as well because you get the power bug once you start!

yeah get good quality big cc injectors straight up 740s will cover you for alot of power...just saves headaches should you wish to upgrade later....

get big cc cheapo injectors now and you risk a crappy idle and bad fuel economy...

can we get a list of possible injectors for high power applications, so far i have deatchworks 1000cc but not sure bout idle and quality and fitment, power enterprise but have found they can have idle issues and be lazy? ID or xspurt 1000's but ill need to mess round with a top feed rail which is not encouraging, and then nismo's which are expensive,

just want to know what is the choice injector. and do it first time right...

Dude, it's a 25.... So many options!!! I went HKS rail and am happy az....

When it comes to advice, Guilt_Toy and Ash are as good as it gets, don't ignore it :)

you can xspurts or IDs in with the stock plenum on a 33 ,fuel rail is only 100$ regs arent too expensive either, fuel hose is cheap also and you will need a pressure gauge which is 20$..

I got.xspurts in 750cc in 40mm, which are shorter than IDs which are 48mm, so makes for an easier fit,, I think both will fit, I'm yet too see IDs with stock plenum but it could be done..

.Injector will cost you 6-700$ and they are amongst the best..Ask anyone and they will tell you they are great to tune, great at idle and great for economy too...

heres mine fitted up, I got them in without removing the plenum, tricky but possible

29012012564.jpg

29012012565-1.jpg

fuel rail

http://goodiesdirect...&product_id=405

Do it once, do it right... :thumbsup:

you can xspurts or IDs in with the stock plenum on a 33 ,fuel rail is only 100$ regs arent too expensive either, fuel hose is cheap also and you will need a pressure gauge which is 20$..

I got.xspurts in 750cc in 40mm, which are shorter than IDs which are 48mm, so makes for an easier fit,, I think both will fit, I'm yet too see IDs with stock plenum but it could be done..

.Injector will cost you 6-700$ and they are amongst the best..Ask anyone and they will tell you they are great to tune, great at idle and great for economy too...

heres mine fitted up, I got them in without removing the plenum, tricky but possible

29012012564.jpg

fuel rail

http://goodiesdirect...&product_id=405

Do it once, do it right... :thumbsup:

Thanks guys , just made my decision easy :thumbsup:

Just one last question, i rang EFI today and also horsepower solutions, 2 recommended on here about ethanol, got two different bits of advice

EFI said a 400lph walbro will be an absolute minimum for 300kw and need 800cc minimum injectors

Horsepower solutions says 2X 044 externals and was very sure about it, said ill use almost double the 98 i use when flat out

so the 2X 044's is extreme dont you think? and said ill make 320kw

now im thinking more that EFI know what there on about, but if a 400lph walbro is minimum what more can i do??

if the gtx3076 is to get upto 22psi without restriction, im thinking a walbro 400lph and Xspurt 1000's, should i expect 340kw's here?????

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


  • Similar Content

  • Latest Posts

    • That's the thing. Especially at idle, changing the cam angle by that much could be spewing more fuel out the exhaust courtesy of everything happening that bit later. More fuel also means more air (if the fuel didn't burn, then neither did the O2) and so the O2 sensors can start to tell interesting but misleading stories. And the specifics of what is happening could easily be affected by everything else you changed as well. And it could be dynamic, where a few revs more or less could somewhat change how the engine is breathing.
    • Good idea on the temp probe. The mv readings of the O2 sensors are very similar to one another, as is the injector pw. I went through logs in the past to see if there was a discrepancy and there is. Because they alternate up and down as narrowbands do.. they do often 'switch' as to which one is more. They were never 20%+ (more like 1-2%) so it's possible the difference between 20 and 15-17% is a similar discrepancy to 2.0% and 1.7% which I wouldn't have really noticed in the past. We did think about spacing the strut brace. Unfortunately the ~20mm that the GTR brace is lower than the GTT brace is effectively what you need to clear the vents. Moving it up would make it very uncomfortable, but it's plausible that 10mm is a unhappy medium between both hard places... The good news is.. using MR HAMMER it was actually pretty easy to bend back the bent bits to make sure the guard and headlight/new headlight tabs line up right. Yes, we used a R34 GTR guard to make sure the bolt holes all lined up with a known straight guard. As above, you can see the side skirt and the GTR guard are not meant to play together, but everyone seems to think this is a simple fix to the point where nobody who has had these talk to one another mentions how... ...so I'll just assume they know how to fix it when it comes to paint jail time again. Whoever they are. Nobody returns my calls. There's so much changed with regard to the ECU and the car.. that the next step really is to connect the scanner and attempt to drive the thing. It'll be pretty clear pretty fast how in or out everything actually is...
    • That's nasty! I think there is perhaps an inherent problem is using elastomers in such environments. The whole thing can and will get quite hot, and elastomers are not famous for their temperature resistance. On top of that, if the components are cast rubber or urethane and so on, there might be QA/QC problems with bubbles or voids in the material that could critically change their performance. They might just tear apart after being squished (presuming that any elastomers are used in compression rather than tension, I'm thinking that you squeeze one with a void in it and it tears the wall of the void to the outer edge of block, then the next time it extends or otherwise twists, it just gives up). This is all purely hypothetical, but it makes me wonder if the things that they have put into it to make it nice to use/live with are perhaps going to cause occasional failures like this. I wouldn't be getting up in arms over it, unless there are many repeats. I have personally ruined an Xtreme clutch - just an HD thing. I can't remember if it was still behind the 20 or was after the 25 went in. But it inverted some of the retaining spring/clip things around the outside. No-one could explain it. It wasn't thrashed, there wasn't heaps of torque being put through it, and there were no obvious problems other than the above. They were quite concerned by the event so they replaced it even though it was a few years old, which was very nice of them. As far as I am concerned, these things happen with clutches.
    • Any damage to the box/input shaft?
    • Hey there Mate , I just got my local guy to install it Waterhouse Performance, Penrith (specialise Nissan/Datsun and other performance cars) , you can do it yourself if you like , AMS has instructions on their website.  Cheers Pac
×
×
  • Create New...