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Injector Sizing For E85

rbs30

By rbs30,
in Engines & Forced Induction

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rbs30 Collaborator

rbs30

Posted
Posted (edited)

Hi all.

Ok so i have decided to save the rb30 build for a later date, mainly because I need to get my motor out, built and back in as quick as possible due to it being my daily and having no spare. Anyway, I have a forged bottom end on its way as well as arp head stud kit plus vrs to rebuild head and gaskets to stock.

I also have a haltech plus a hg 43g3 on the way and walbro fp. My question is, I have some 800cc injectors here from a previous build. Do you think these will be enough? I know 300kw is prob starting to push them but will I get away with it for a while? I havent played with e85 before so i dont even know if 300rwkw is even realistic with that setup. Opinions? Thanks in advance.

Edited by rbs30
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s213b Rising Star

s213b

Posted
Posted (edited)

From what I've gathered, you need to pretty much double your injectors for an e85 build. If your turbo is in that range and you've got a decent tuner 300rwkw on e85 should be a breeze.

I'm currently pricing up an e85 build on my rb25, aiming for 400-450awhp and have been told I'll need a big fcker of a pump and 1000cc injectors.

My guess is should be ok with upped fuel pressure

Hope that helps

Edited by s213b
The Dan Grand Master

The Dan

Posted
Posted

Hi all.

Ok so i have decided to save the rb30 build for a later date, mainly because I need to get my motor out, built and back in as quick as possible due to it being my daily and having no spare. Anyway, I have a forged bottom end on its way as well as arp head stud kit plus vrs to rebuild head and gaskets to stock.

I also have a haltech plus a hg 43g3 on the way and walbro fp. My question is, I have some 800cc injectors here from a previous build. Do you think these will be enough? I know 300kw is prob starting to push them but will I get away with it for a while? I havent played with e85 before so i dont even know if 300rwkw is even realistic with that setup. Opinions? Thanks in advance.

800cc injectors = 435hp at the wheels

We used to devide injector size by 12 but have found it to be more like 11

rbs30 Collaborator

rbs30

Posted
  • Author
Posted

435rwhp = more than 300rwkw. So I should be right. But I may be better to just go 98 Ron for the moment and up injector size and retune in 6 or so months when I have cash. Don't want to be too close to the limit.

435rwhp at what duty cycle?

The Dan Grand Master

The Dan

Posted
Posted

435rwhp = more than 300rwkw. So I should be right. But I may be better to just go 98 Ron for the moment and up injector size and retune in 6 or so months when I have cash. Don't want to be too close to the limit.

435rwhp at what duty cycle?

435rwhp is a safe maximum assuming your pump is up to the task.

For 300rwkw (400rwhp) you need 4.5L/min fuel flow to be safe

Bratva Community Regular

Bratva

Posted
Posted

If i have 750cc injectors and i go for a tune with a nismo fuel pump @ 14v how much rwkw can i expect ? I am wanting hopefully around 320rwkw on E85.

Or should i grab some 1000cc injectors to be safe ?

And if i want to drive to the tuner, can i just plug in that nistune cable and then set the injector size on the pre-existing tune or is there more to it ?

Thanks

Mick_o Grand Master

Mick_o

Posted
Posted

If i have 750cc injectors and i go for a tune with a nismo fuel pump @ 14v how much rwkw can i expect ? I am wanting hopefully around 320rwkw on E85.

Or should i grab some 1000cc injectors to be safe ?

And if i want to drive to the tuner, can i just plug in that nistune cable and then set the injector size on the pre-existing tune or is there more to it ?

Thanks

Need to know more than what injectors u have mate lol! The nismo pump will be fine I believe they are good for up to 400kw........Stand to be corrected if I'm wrong lol
rbs30 Collaborator

rbs30

Posted
  • Author
Posted

Ok cool. Sounds like it will be close enough. I'm running a walbro 90000267 e85 pump. If that runs out ill just use my old one as a lift pump and run 2 of the e85 pumps off a surge tank.

I think the way to go is to just run e85 and tune it to a safe injector duty cycle and be happy with it until I've got money for bigger squirters.

Cheers for the assistance.

Bratva Community Regular

Bratva

Posted
Posted

Need to know more than what injectors u have mate lol! The nismo pump will be fine I believe they are good for up to 400kw........Stand to be corrected if I'm wrong lol

Its already made 304rwkw on 98 fuel so the other mods are fine, im just worried the injectors are too small for e85. Is it bad if they are at like 90% duty cycle ? Its not a track car so i wont WOT all the time.

NYTSKY Grand Master

NYTSKY

Posted
Posted

If i have 750cc injectors and i go for a tune with a nismo fuel pump @ 14v how much rwkw can i expect ? I am wanting hopefully around 320rwkw on E85.

Or should i grab some 1000cc injectors to be safe ?

And if i want to drive to the tuner, can i just plug in that nistune cable and then set the injector size on the pre-existing tune or is there more to it ?

Thanks

I have made 360rwkw with Nismo 740cc with some head room. You will be fine at 320rwkw.

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