Small Injectors - <150cc/min?

[knightrous]

I'm currently looking for injectors in the 140 - 150cc/min area for a staged injection setup for my 1MZ. I've done some research and the only injectors I can find in this range is 4KE injectors, and I've yet to find any for sale anywhere (let alone six). I've started looking at the Yaris motors (1.0L 1SZ-FE & 1.3L 2NZ-FE) but I cannot find any specs on injector flow, impedance or feed positions (top or side).

If anyone knows of some small, top feed, hi impedance injectors, I'd really appreciated the tip off

[jonathan yee]

here's some

http://autospeed.com.au/cms/title_In...2/article.html

[knightrous]

I've looked at those before, but I've had troubles finding them for sale anywhere, so I started looking towards newer cars where they are still commonly available.

[oldcorollas]

i might have some 4KE ones in the near future.. only 4 of them tho, but there may be others round

look at the ons in Kei cars too

[mattysshop]

could you use some 4afe injectors 23250-16120, which are 177cc/min at 41psi... and high impedence..

if your running a second fuel rail for these, would it be too difficult to run a lower fuel pressure? say 35psi, which would kill about 20cc flow? those are readily available from any wrecker in brisbane, you can grab pockets full..... for free

possibly even 4EFE starlet injectors?? there only a baby 1.3L 4 cyl... the fuel per cylinder required and the fact that they make 50kw of raw power leads me to think they would be around the 150cc or less..


i know the 4AFE ijnectors the green/greyish colour (23250-16120) are 177cc per min, i confirmed this part number with a number of websites for a turbo application..

this website is very handy..
http://users.erols.com/srweiss/tableifc.htm

[knightrous]

I'd be worried about dropping the fuel pressure as it will probably affect the spray pattern of the injector. However, if I can get a bunch of them for cheaps, compromise is always possible

[mattysshop]

if you were cutting the pressure in half i'd be worried, but think of how a vac fuel pressure regulator works... 90% of the time the injectors arn't seeing anywhere near there 'max' pressure... only when there is no vac (WOT) or in boosted applications where the pressure is increased dramatically..

hope that helps

some manufactures run the same injectors in different engine at different pressure's...

[knightrous]

Thanks for the comments mattysshop. + rep.

I've found Bosch 150cc injectors new for ~$60ea online, just checking out if I can get them cheaper through some other channels. Some new injectors for the setup I want probably isn't a bad thing compared to some 20+ year old 4AFE injectors, will see how far the budget stretches...

[oldcorollas]

if you were cutting the pressure in half i'd be worried, but think of how a vac fuel pressure regulator works... 90% of the time the injectors arn't seeing anywhere near there 'max' pressure... only when there is no vac (WOT) or in boosted applications where the pressure is increased dramatically..

hope that helps

some manufactures run the same injectors in different engine at different pressure's...

the pressure reg maintains a set pressure drop across the injector, so for example, the injector always has a 40psi pressure drop across it, regardless of the manifold pressure...

[mattysshop]

could you explain more on that oldcoroolas?

all of my experience is that say you disconnect the vac line to the FPR (i'll use a typical 16v 4age for example) hold your thumb over the vac line ofcourse to not get a fast idle... it runs quite fat and rich...

i came across this when i was running my 20v itb's on a stock bigport MAP ecu.. would run and idle no worries with it connected, but if i took it off, it would run rich.. i put it down to the increase in rail pressure as there was no high vacuum holding it open..

example is nissan SR20DET - idle fuel pressure is 34psi, disconnect the vac line fuel pressure raises to 43psi, and when boost is added 1psi boost = 1psi extra rail pressure


ofcourse i'm only talking about FPR's with a vac line and return line, no he returnless, or regulated at the pump type systems..

[Joshstix]

It's simple if an injector is designed to make it's best spray pattern with a pressure differential across the tip of 40 psi then that is what it should be run at. Now if the pressure of the air around the tip of the injector is -5psi then the pressure of the fuel behind the injector to get the same pressure difference across the tip would only be 35psi.

The spray pattern is about the pressure differential rather than the absolute pressure of hte fuel supply.