Injector Size

[muzziak]

Hey guys, I've got a r33 with an rb25det in it, following are the mods;

-splitfire coilpacks

-power fc

-FMIC

-3' turbo back exhaust

-Z32 afm

-570cc denso injectors

-walbro 255 fuel pump

-Hypergear ATR43SS-2 turbo waiting to be installed

-gizmo EBC

And probably a few more

Question is, im chasing about 270-280 with the new turbo and tune, however my tuner was saying the injectors might not be big enough and should upgrade a 460 fuel pump to mitigate the issue. Talked to a few other people and they said don't bother just upgrade injectors.

What does everyone reckon ? Upgrade fuel pump and keep and injectors and scrape by or just go bigger injectors, and if so, what size and brand ?

Thanks in advance for any help

[GTSBoy]

The injectors are large enough. They will support over 300 rwkW. That is getting a bit close to the margin, so if you want some comfort then sure, upgrade. Your best bet would be Bosch EV14 based ones. Probably 1000cc would be the best choice. They'll be much better injectors than those nasty old school Denso ones anyway, so don't worry about them being too big.

The fuel pump will probably be fine. Too big a fuel pump causes unnecessary fuel heating - so it's not a free choice anyway.

[muzziak]

Thanks for the feedback, hmm so it's more a personal decision. Would keeping the 570's and pushing them to the limit cause any possible problems in the future in your opinion ?

[iruvyouskyrine]

I would probably keep current injectors and get the Walbro and bump the base pressure up a little bit personally.

[KiwiRS4T]

Those injectors will do over 350kw

If you have the stock pump (i.e. a 20 year old one) get the Walbro and directly wire it. FPR will be fine.

[muzziak]

Well this has just made the decision that much harder, tuner and mechanics saying go bigger. But thanks for the feed back guys

[KiwiRS4T]

Well this has just made the decision that much harder, tuner and mechanics saying go bigger. But thanks for the feed back guys

Well mine made 314AWKW with 550s and had plenty of room for more. Name the workshop that says you won't make 300 on 570's !! I reckon they will do 350 at least if not more.

However if you have money to burn stick some ID2000s in and you will not have to change them for a while.

[muzziak]

Preferably I'd like to keep the money, but was just worried about the duty cycle and whether the car would be struggling. But everyone's pretty adamant that it will hold up just fine, thanks guys. If I do keep the 550's, should I upgrade the fuel pump or stay on the 255

[scotty nm35]

255 Walbro will flow 400kw give or take on 98.

[muzziak]

So that will be plenty. Just comes down to the injectors, thanks for the help guys

[muzziak]

Sorry guys turns out there denso 550's, still capable ?

[GTSBoy]

Good for 20HP less than the others.

[skyline32sup]

570cc injectors at 80% duty cycle 1 bar of boost will make 324kw - ish on 98 , I recommend not going over 80% duty cycle, and more fuel is better than not enough. Your 255 fuel pump will be fine aswell. I wouldn't change anything.

Edited July 4, 2015 by skyline32sup

[skyline32sup]

That's 324kw at the flywheel my bad, so making it around 280kw at the rear wheels, is be looking at bigger injectors

[Beau1988]

I've been running standard injectors with the car making 290 rwkw, had that setup for 5 years plus.

[KiwiRS4T]

Your injectors and pump will be fine. My 550s have done 314AWKW and good for at least 350 .

[Ben C34]

I've been running standard injectors with the car making 290 rwkw, had that setup for 5 years plus.

Rb25 Injectors?

[Beau1988]

Yup

[Ben C34]

Oh. That's interesting.

[GTSBoy]

Oh. That's interesting.

As in......impossible?