Bigger Injectors - Stage 2 LCR - OE K04

JamJay

California Bound
Hi all,

I know I'm not the only one so I thought I'd post up in here for some more info. A lot of us running Stage 2 map/Stage 2 mods/3" TIP are now maxxing out our fuel injectors with 220g/s+ airflow readings which is no good. I'm not totally clued up on the matter but my understanding is that the car is requesting more fuel than the OE injectors can supply which will hinder performance potential surely. What knock-on effects would maxed injectors have?

Does anyone know the 'cc' rating of the OE injectors at all? Secondly, which injectors would be a good replacement? Obviously new injectors will need to be mapped in but what would the benefits be of this modification?

Thanks :)
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
31,333
19
glos.uk
4bar reggy is cheapest option... or 440's
ecu adjustments will be required. (unisettings for example)

important aspect is that 031 does not fail to achieve its requested lambda.. block 001 under wot would show how much % adjust lambda is having to make to try and achieve this number.

where it goes 0.75/0.69 its probably 112 egt fuel dumping as its hit 920'c
 

JamJay

California Bound
Thanks Bill aka The Oracle :). What benefits would you expect to see by fitting and mapping in 440's?

Edit: Been doing some reading and it sounds like Bosch 440cc are popular however with a reported crap spray pattern. I've never heard of a fuel pump failing due to 4bar FPR so could be the best way to go.

£58 from Awesome
£76 from JBS
 
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DaNnY_LaD

Big Turbo Leon Cupra R
Jun 2, 2007
4,814
1
Manchester,Walkden
www.myspace.com
Yes I was the same with maxing out injectors @ 6100rpm and holding 21psi of boost which was 104% duty...

Currently put my Audi rs4 70mm throttle bodie on and the duty was wayyy off but it moved the maxing of injectors too 5850rpm..i fitted a 4bar reg which in turn helped it out but there was no head room


440Cc are cheapest by far but il have to try them soon...
 

matylad

Full Member
Nov 24, 2005
279
0
Crewe, Cheshire
4bar reggy is cheapest option... or 440's
ecu adjustments will be required. (unisettings for example)

important aspect is that 031 does not fail to achieve its requested lambda.. block 001 under wot would show how much % adjust lambda is having to make to try and achieve this number.

where it goes 0.75/0.69 its probably 112 egt fuel dumping as its hit 920'c

Bill,

Is this the problem I am currently seeing? Would new injectors/4 bar FPR be a fix?

Matt.
 

Mo Arif

V.A.G Planet
May 5, 2010
2,510
0
Birmingham
This doesn't apply to a LC does it? I've got a 4 Bar FPR on a pretty aggressive custom Stage 2 map
 
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Pyro

Guest
Thanks Bill aka The Oracle :). What benefits would you expect to see by fitting and mapping in 440's?

Edit: Been doing some reading and it sounds like Bosch 440cc are popular however with a reported crap spray pattern. I've never heard of a fuel pump failing due to 4bar FPR so could be the best way to go.

£58 from Awesome
£76 from JBS

Think there £50 from AMD but postage could put it up :shrug:
 

carlossus

Active Member
Nov 13, 2010
153
0
Bournemouth
I read that once injector duty cycle goes above 80% the reliability of the injector to accurately dose out fuel becomes questionable!

The injectors meter fuel based on open time. 100% is one half cycle so over 100% is still accurate, but the injectors will get getting less off time to cool so reliability might suffer.
 

Mark300zx

Active Member
Apr 24, 2008
1,458
8
Surrey/SW London
I think reliability and dosing suffer don't they, if you read the injector manufacturers website they always say never go above 80-85%, there is also a trade off in upping the fpr as this can delay the the injector but also creates a higher pressure finer spray more desirable in higher boost applications?