Jump to content
SAU Community

Recommended Posts

heya all, first time posting on here, and probs a stupid post, coz its probs been covered somewhere else. :\

anywayz just wondering if (A). a fuel pump upgrade would b a good investment on an 94 gts-4 non-turbo

if so whats the best brand? and what would the power gain ( if any) b?

(b). also injectors, would it b worth it, if so what cc would b the best and what brand??

cheers. :thumbsup:

Link to comment
https://www.sau.com.au/forums/topic/215181-fuel-pump-injectors-upgrade/
Share on other sites

quick answers

yes, walbro, tomei, no, no

yes - the pump is a worthwhile upgrade as they are getting old

walbro or tomei or any other number of brands are good

no power upgrade by changing the pump, although you might get some top end power back if it is starting to choke (but you would be able to feel that in teh car)

only do injectors if the duty cycle is almost or is at 100% - which it wont

duty cycle is the amount of time the injector is open

50% duty cycle means the injector is injecting fuel 50% of the time

so in 1 sec of engine running the one injector has been adding fuel for 0.5 sec

a 100% duty cycle means the injectors are at their capacity and are injecting fuel in the whole time

heya all, first time posting on here, and probs a stupid post, coz its probs been covered somewhere else. :\

this tells me that you are lazy. do not do this again please.

yes - the pump is a worthwhile upgrade as they are getting old

walbro or tomei or any other number of brands are good

no power upgrade by changing the pump, although you might get some top end power back if it is starting to choke (but you would be able to feel that in teh car)

only do injectors if the duty cycle is almost or is at 100% - which it wont

correct.

most normally, people only do fuel upgrades if they are running out of fuel. if your engine is getting ample then upgrading won't do anything.

Why not just upgrate to DET items? Saves you a HEAP of money!..

Money that could be spent on getting something that would acctually increase power/responce.

I wouldnt really bother. Unless your planing or doing mods tht will require a higher rate of fuel to be used.

Dont replace things for the sake of replacing them. Replace them because they need to be replaced. If they can be repaired of fixed, do that then automatically forking out a few hundred dollars for something new.

Edited by GTS4WD
  • 1 month later...

you will find a lot of DET stuff will fit straight onto the DE engine. I have R34 GTT Fuel injectors and they work perfectly. Also have a R34 GTT Power FC to go with them, so any other upgrades i do future wise the tuning will be easily done.

yeah of course it will go straight in, but with a stock na rb25 theres no point sticking det injectors in unless you require more fuel which he wont.

Bigger injectors when not needed = no performance gain = waste of time and money

Edited by R34GTFOUR
sum of us have nitrous tho :) therefore bigger injectors come in handy ;) and once i get bigger cams and all that ill be getting 450cc's!!

haha i know you'll need them, i've seen some of your posts that suggest nitrous interest ;)

Im just saying in a stock setup theres no point upgrading injectors

Edited by R34GTFOUR

thats true steve, and i definatly agree.

however even if u were to upgrade the injectors in a stock setup an aftermarket ecu is needed as the stock ecu wont work with them (i found that out when i was looking into the bigger injectors)

spot on with the ecu upgrade cara.

that said, injector installation is a relatively easy job - it's not essential when making power. a good tuner should be able to tell you when they are maxing out, i believe that unless your current ones aren't up to the task then it's just a waste of money.

i've seen rb25de's run nitrous without the need of injectors, just depends how much you intend on running and what kind of tune you have.

for me it was more of a safety thing when i decided to get the bigger injectors, i just didnt want to take the chance that the stock ones might max out..............they 370cc's will defetinly come in handy when putting bigger jets in tho :geek:

Guest NVDGTS4

lol yeh i just upgraded my standard GTS-4 Fuel pump to a Walbro 255LPH Fuel Pump. took about an hour to put in and modify the braket to hold it in but yeh its a freakin noisey bugger but sounds cool hahah you can hear it alol day long pumpin fuel haha. But yeh didnt really give any performance at all does seem to rev smoother past 5500rpm but . only cost around $150 for upgrade with new Walbro

is the nos hooked up now?

what shot size you going?

should be quite interesting :D

yeah it is..........started off with 55hp got 171 kW's n/a was doing 128 kW.

ive got 75's and 100's to go eventually need to get a bigger fuel pump for the 100's

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

    • Maybe they'll look to do a bunch of presales to help inject some cash fast for their financial issues...
    • Does it also misfire equally when revving?   Josh is very correct in what you should do. The coilpack harness wiring loom itself is a known problem due to its age and the number of heat cycles it has gone through. Throwing parts at a vehicle to diagnose the issue isn't a smart or good way to do it. Secondly, you may have a bad coil pack, you pop replacements in, they fix that issue, but messing with the harness breaks it, so the issue persists. So now you think "well it wasn't the coil packs" and have to continue chasing your tail, potentially swapping back in your shit coil packs and returning the good ones (yes, I've seen people do this because 'it wasn't the problem' and they want to save money). And suddenly, you've got two issues with the same symptoms...   Diagnose, don't use the spare parts shotgun.
    • Well the articals keep saying a Q50s (Skyline in Japan) with a new Manual gearbox. I like the talk about the new looks with the round tail lights. I hope they bring back the retro look like they did with the Z
    • Off the back of feedback we have decided to mix up this next Motorkhana at Avalon to have some targeted skills practice for beginners to advanced. Saturday 6th September 2025 8:30am Capped 26 entries Standard Entry Fee: $89 Members Entry Fee: $55 (SAU Victoria Only) Entries Close: Friday 5th February  Where: 55 beach road Avalon. https://maps.app.goo.gl/HNUE3EuNue3sJxh38 Entries: Limited to 26 entrants (Passengers allowed over the age of 14 with a signed disclaimer and same safety gear) Disclaimer: Download  Please electronically sign and email to [email protected] or print and hand in and Driver Sign In. To compete in this event you will require A valid  AASA General Speed licence or (Day license via the AASA Website for $50) MA Licenses are no longer accepted by AASA https://aasa.com.au/  A helmet, long sleeve clothing and a 1KG mounted fire extinguisher recommended (But not Mandatory). Further details within Supp Regs on the enty link. Entry Link > https://www.sauvic.com.au/entry/deca/20250906 You can bring and have a passenger in the car but they need to comply to the same safety and clothing as driver. Bring your car and get to battle others, win, lose or draw. I can guarantee you will have lots of fun. Any questions email [email protected] Entry List: 1.Anna S 2. Luke S 3. Jesse Givens-Lamb 4. Luca Stamatescu 5. Madeleine Stamatescu    
    • Wanna rewrite all of that in, say, 2 or 3 separate sentences, so that we can read it?
×
×
  • Create New...