Fuel Pump, Injectors Upgrade

[r33frenzy]

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.

[342Four]

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

[r33frenzy]

cheers bro, just wondering wtf is a duty cycle? lol

[342Four]

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

[r33frenzy]

kewl, cheers again man.

[Eug]

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.

[GTS4WD]

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 April 17, 2008 by GTS4WD

[madevo3]

yeah get a rb det motor then put all the stuff you said you want and you will see a huge difference

[dori34]

with such an old car, chances are the fuel pump might not be flowing at its full potential.

best to get it fuel pressure tested and if its low, make the necessary changes..

[R34GTFOUR]

yeah get a rb det motor then put all the stuff you said you want and you will see a huge difference

you're joking right???

[MissR34]

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.

[R34GTFOUR]

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 June 13, 2008 by R34GTFOUR

[MissR34]

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!!

[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 June 16, 2008 by R34GTFOUR

[MissR34]

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)

[Eug]

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.

[MissR34]

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

[R34GTFOUR]

is the nos hooked up now?

what shot size you going?

should be quite interesting

[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

[MissR34]

is the nos hooked up now?

what shot size you going?

should be quite interesting

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