Jump to content
SAU Community

Recommended Posts

I have 660cc denso injectors im pushing out 220rwkw

but on normal driving im only getting just under 300km per tank

i know i went over kill on my injectors but do you think if i went the gtr injectors

it would be worth it Would i save more fuel or will it be the same still?

Im running a wolf ver 5

Link to comment
https://www.sau.com.au/forums/topic/157793-injectors-and-fuel-consumption/
Share on other sites

The injectors are way overkill for the power you are developing. What is your power target?

Obviously it would be easier to achieve fine control at light load with smaller injectors, but I'd suggest two main culprits:

Your light load AFR

Your driving style. Use lots of throttle and a bit of rpm, and you will use fuel; it's that simple.

Injector sizing may be a small part of the issue, but I'd look at the other two as the main cause of fuel use.

I have similar max power to you, but consistently deliver 400-440km per tank (50-52 litres to fill).

cheers.

660cc injectors are overkill for that power requirement. Most guys on SAU have had good results with 550cc which will more than feed what you want. However, run what you have, and aim on good consistent tuning.

Here's a development log I made in the past week:

post-19642-1172280065.jpg

Pretty self explanatory, with the numbers being average AFR:1 logged during a run, with O2 feedback turned off. My target from P3 - P9 load is 14.7 but I tolerate a variance of between 14.6 - 14.8. Extensive data logging has shown that you do get variance from run to run, but multiple variance analysis shows that over the long run it is fairly tightly controlled. There is a bit (lot) of mucking around to achieve the consistency though.

I'll pull up a shot of injector duty cycle too, just to demonstrate how much increase you get with load.

Check out how fast the flow requirements ramp once you load the engine in any rpm range, and if you keep sticking the revs into it. And if you've got more power, then you're going to use more fuel.

If you want economy then you need to keep it in that light load zone.

post-19642-1172280968.jpg

So the answer remains the same:

mechanical spec (this includes injector flow rating) will play a part, but not as big as you might think

tightly controlled AFR is important (yep, tuning)

controlled use of the throttle is the major factor

Hope this helps. :(

cheers

Dale

I got 430rwhp with PFC & AFM with Nismo 740cc injectors and on my last RTA Emissions test it recorded 11.8 litres per hundred which is over 500ks to a tank (60 litres) it did fail the emissions test because i tuned it to run good on fuel.. now after i retuned it it uses more fuel then before (keen to pass this test)

So yeah you can have big injectors and get good fuel economy. maybe its the computer that cant handle the injectors properly i do keep hearing that apexi power fc's handle big injectors well so that may be why mine is the way it is.

im getting my tuner to have a look at my cam timing cause he thinks its reterded a fair bit

im not making good power for what i have in my car and its all possibly related i will let you all know how it goes

its going in next monday

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

    • I've looked up the parts number (41011AL501). It's around $700 OEM. Usually our Infiniti G35 here in Canada have interchangeable parts with my Stagea but the parts number are not the same. I have looked around and it seems the JDM 2005 V35 Skyline (which is the same as our G35) has the same caliper but I cannot confirm. And I can't find a repair kit. The inner brake pads drags on the rotor, seems to be rusty piston. Thanks for the info by the way
    • This coupled with 6-9 speed autos with ridiculously short gearing is why these modern shitbox cars always seem so fast off the line. If it wasn't for those things, Raptors would not seem fast. The problem we have is there is a driveability gap between a more gentle take off and a wheelspinning sideways launch. The difference between ankle flex required to achieve one and ankle flex required to achieve the other is about 0.5°.
    • Yeah I think I'm also with the opposite here. It's 'hard to keep up with traffic' because in the real world I'm accelerating with 15% throttle and they are pinning it. It feels like I'm being an overt dickhead at anything above 15% throttle, so the car sounds like I'm being an overt dickhead to keep up with/get ahead of traffic when I'm really just trying to drive with traffic. There would be no issue 'keeping up with traffic' if we used the same level of throttle input/aggression to drive around. People really do just drive around with their foot nearly pinned in econoboxes.
    • To be fair it's the other way around. 300kw is boring in a modern Golf or BMW. They are so competent / well-engineered / devoid of emotion that you have to go stupid fast to feel anything. Whereas the <300kw RB still makes all the right noises and it feels good to drive. Can pull off at the lights with the turbo whooshing and the blow-off pssshing and feel like the coolest kid on the block. Just don't look to the side where you'll see the bored housewifes in their shitbox Yaris/Corolla/Camry that kept up because you didn't go fast at all
    • 300kW is so boring in a Skyline, you'll get spanked by someone's mum's Golf with Alibaba pipes, and an email tune.
×
×
  • Create New...