Rb25 Fuel System Upgrade

[16389]

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

[NYTSKY]

Forget the reg, stock one is fine for 99% of peoples power goals, put that extra money to a Nismo fuel pump. Happy days.

[Mitcho_7]

What turbo do you have and how much power do you want?

[16389]

will be running a hi flowed stock turbo from unique auto sports. unsure of wat core will be used (prob should find out) but they recommended pump upgrade and either a regulator or injectors. hoping for 240-270rwkw

[Mitcho_7]

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

[34GeeTeeTee]

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

[R31Nismoid]

Forget the reg, stock one is fine for 99% of peoples power goals, put that extra money to a Nismo fuel pump. Happy days.

This man.

He knows.

[16389]

cool, thanks guys that helps a lot! Anyone had any dealings with unique auto sports in sydney?

[Mitcho_7]

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!

[ARTZ]

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...

[AngryRB]

This man.

He knows.

what nismo pump are we talking about ? from what ive seen they flow about 250lph roughly, is that great? i must be missing somthing ....?

[AngryRB]

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...

[34GeeTeeTee]

360kw as you know, XSPURT 1000cc injectors, stock idle with cams....

Don't be a tight ass, you won't regret it.

[Guilt-Toy]

This man.

He knows he knows.

This man.

He knows.

[AngryRB]

This man.

He knows he knows.

what is your injector and rail?

[34GeeTeeTee]

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

[ARTZ]

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

fuel rail

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

Do it once, do it right...

[AngryRB]

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

fuel rail

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

Do it once, do it right...

Thanks guys , just made my decision easy

[AngryRB]

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?????

[Mitcho_7]

A few people seem to manage fine with an 044 intank (wired for alternator voltage), so I don't think you will need 2 of them. A Nismo pump might also be enough, but go the 1000cc injectors like everyone has suggested.