5th injector & fuel pressure switch question

[novascotia_zx2]

did some reading and i have a question for you guys who know about this.

you basically hook a '5th' injector up close to the throttle body, it sucks in fuel , that fuel makes it into the chambers where the air goes to ignite and creat combustion in your engine. so i get the concept.

how do u prevent it from igniting in the plastic intake manifold before it makes it way down the cylinder ( someone commented this can happen and cause ur intake to explode.)

secondly.. if i have a spare injector ... what do i create to control the injector so it sprays when i want it to.

injector controllers on the net im reading about them and there confusing the hell out of me... any easy way to explain the use of an injector controller tome and how i can make one .. or buy one really cheap? i think i want to try this 5th injector idea.

[tre2000zx2]

did some reading and i have a question for you guys who know about this.

you basically hook a '5th' injector up close to the throttle body, it sucks in fuel , that fuel makes it into the chambers where the air goes to ignite and creat combustion in your engine. so i get the concept.

how do u prevent it from igniting in the plastic intake manifold before it makes it way down the cylinder ( someone commented this can happen and cause ur intake to explode.)

secondly.. if i have a spare injector ... what do i create to control the injector so it sprays when i want it to.

injector controllers on the net im reading about them and there confusing the hell out of me... any easy way to explain the use of an injector controller tome and how i can make one .. or buy one really cheap? i think i want to try this 5th injector idea.

1) it does go into the intake before the tb... works SIMILAR to a wet nozzle with nitrous or methanol... goes after the MAF but before the TB..
2) the chance of ignition in the intake(back fire) is minimal its similar to a nitrous backfire .. rare.. but can happen.. but can happen in a car without either.. timing adjustments can make this more likely or less likely. ( intake cam and igntion play a role)
3) as for making the injector fire module .. ive seen a few writeups on making a standalone controll unit.. several tuning options such as MS and most stand alones offer an additional injector sequence.. its mainly used as a cheap way of extra fuel when your borderline maxed on your current injectors but IMHO HIGHLY unneeded on a zx2 unless your going WAYY big.. we have quite a few cheap stock injector options available up to 42lb (easily acquired lightning ones )and way beyond if you go aftermarket.

[jeffescortlx]

how do u prevent it from igniting in the plastic intake manifold before it makes it way down the cylinder ( someone commented this can happen and cause ur intake to explode.)

Ask any body that had a car or truck from the 80's that had CFI injection (basicly every vehical on the road at that time) how many times they had a exsplotion in there intake manifold.

[Alwayssideways]

are you talking like a TBI setup? im confused

[novascotia_zx2]

ugh.

so how can i control the injector? i'll hook it up infront of the throttle body ... but i will need to control when it spray's. how cost effective will this method be?

seems like it would bandaid any lack of fuel i might see running boost on a stock tune... better safe than sorry it wont be very accurate but it will help.

you guys claim you can run 4lbs on a stock tune.. and those have run up to 6psi for an entire year with nothing added... so extra fuel will make my car extra happy in that case.


i priced bolt ons VS doing a home made turbo and no matter what i will win the arguement that 4psi of boost on a home made build is better spent than a $300 brand name air intake , and $300 header , and $300 cat back thats almost a $1000 bucks and ive only spend about 200.


so.. google isnt helping me any .. its only confusing me more what i read online about injector controllers.. its all falling back into the $$$$$$$$ lol.

some guy makes his own in barbados lol but that doesnt do me any good here in canada.

[novascotia_zx2]

there must be something at a hardware store.. or somthing i can modify to work as an injector controller without having AEM stamped on the damn thing

if i could better understand them maybe i could make something

i'll look it up on that wikipedia thing later lol when i get back fromwork

im all about low cost configuration.:)

[Beodude123]

Instead of trying to fab something up that is a very poor way to manage fuel, why not get larger injectors, and a tune? It's one thing to skimp on your turbo and such, but fuel and spark are what is going to kill your engine.

[Beodude123]

But to answer your question about a 5th injector... You would need SCT or some type of tuning to do stuff like that. You could make it boost sensitive, so that it comes on when the boost comes up. I don't know if SCT can add injectors though. Megasquirt would probably work, but I know very little about it. Only that you have to build your circuit boards and stuff... I think.

[ZX2Slow]

http://sdsefi.com/eic.html

[jeffescortlx]

But to answer your question about a 5th injector... You would need SCT or some type of tuning to do stuff like that.
So your saying every one that has sprayed a 50 wet shot has needed SCT or tuning? I'll answer that for you - NO.



I don't know if SCT can add injectors though.
Since SCT uses the factory ECU, and the ECU only has 4 injector drivers then no, it cant control a 5th injector. But if he went as far as getting SCT he could just get the right size injectors to start with.

[Beodude123]

So your saying every one that has sprayed a 50 wet shot has needed SCT or tuning? I'll answer that for you - NO.


A 50 wet shot has a nozzle for fuel, and it controls when fuel is added. That's not something that you could fab up very easily in relation to boost pressure. I don't know, maybe it is. Either way, my point is that on a nitrous system, when you arm it, it gets the fuel ready, so comparing it to an extra injector is kind of pointless.

[jeffescortlx]

so comparing it to an extra injector is kind of pointless.

um no, they do the same thing. Add's fuel from a single point by sparying into the intake manifold. The only difference is how it's controlled and measured.