Using a 5th injector instead of safc, etc... [Archive] - Hyundai Elantra Forum

: Using a 5th injector instead of safc, etc...



Mahonroy
09-27-2004, 06:25 PM
I know most people plan on using a piggy back fuel controller such as a safc, mafterburner, etc. But after doing a little research on 5th injectors it almost seems like this would be an easier choice? What do you all think about using a 5th injector? because I am almost kinda leaning towards this more than an safc. I am under the impression that I can leave my stock injectors in, buy 1 more stock 190 cc injector, or 1 thats a little larger (depends on expected horsepower, I am planning around 180-200, so another stock would probably sufice). You mount the injector either inside the throttle body before the butterfly valve, or inside the charge pipe right before entering the throttle body. Hook up a "T" connector to the fuel rail and connect it to the 5th injector. And then get an injector controller, hook it up to the injector, the RPM signal comming off the engine, and either a MAF signal or throttle position signal (do they hook up to manifold pressure/vacume hose?). Even though fuel doesn't flow like air does, so the fuel will get un-evenly dispersed throughout the cylinders, it does seem like a good option for a low boost setup right? What 5th injector controllers do you all recommend, and would another 190cc OEM injector sufice for a low boost setup (180-200 hp)? Thanks any info is greatly appreatiated!

OdessitPashka
09-27-2004, 06:36 PM
i guess its ok for a low boost applications. you will never be able to have perfect a/f ratios, and you will most likely have a very lean spot once when turbo starts spooling and injector hasnt given enough fuel yet.... but it could work :)

Speed-Factor
09-27-2004, 06:50 PM
If you are looking to run a Fifth injector this would be your best option: http://www.haltech.com/f5.htm

OdessitPashka
09-27-2004, 06:56 PM
good deal tim :)
But you will never be able to raise the boost over 7psi with that setup, and trust me once you become boost you will want to get more and more boost!!!!

O_GT
09-27-2004, 07:42 PM
Haltech = money

Mahonroy
09-27-2004, 09:53 PM
Can the haltec use a MAF signal instead of the MAP signal?

2GTS
09-27-2004, 09:56 PM
good deal tim :)
But you will never be able to raise the boost over 7psi with that setup, and trust me once you become boost you will want to get more and more boost!!!!
Why would you be limited to 7psi? Where do you come up with this suff ? I swear you're just pulling numbers out of your *** half the time.

OdessitPashka
09-27-2004, 11:54 PM
and i swear you need to spend more time reading forums and books before even posting here!

And to answer your question I think haltech will work with both!

Mahonroy
09-28-2004, 12:25 AM
and i swear you need to spend more time reading forums and books before even posting here!
Gee, thanks :cool:

OdessitPashka
09-28-2004, 12:29 AM
I wasnt refering to you man. 2gts was just being a smart ***....

Speed-Factor
09-28-2004, 12:52 AM
Not really too expensive compared to the unichip: http://www.westcoastfiero.com/haltech/haltech_pricing/f5.htm

FordFasteRR
09-28-2004, 09:44 AM
well, i dont know where he got the 7 psi limit theory with 5th injector setup...

I think that the limit is dependent on the size of the injector, not the boost level....

for example: Lets say you want to have a fuel system that will support 100 hp more than stock on the XD...

you can use a 5th injector to supplement fuel by adding a 750 cc injector. SO.... 49.5 psi fuel pressure, + .60 BSFC + .80% Duty Cycle x 1 injector = 100 crank extra HP.

now, the question of distribution comes up.. but that is ANOTHER disucssion all together... this wetup will support 100 extra hp. Period.

also, if anyone wants to try some different calculations, try my injector calculator here: http://www.nitrousworld.com/elantra-injector-tech.php

thanks :)

OdessitPashka
09-28-2004, 09:48 AM
the fuel will not be distributed evenly and you cant just go for big power with this kind of setup or you'll just blow up! and FYI i get those numbers from maximum boost.....

2GTS
09-28-2004, 09:57 AM
No I'm not being a smart ***, I just want a little more info as to why things won't work before believing someone spouting off numbers. So you've read a book, that's great but it doesn't make up for the fact you have yet to own a turboed car and I will not take advice from you with out a source being given as you have been proven wrong in the past. I still don't believe 7psi is the max you can run with a 5th injector or another style of supplemental injector setup. From one turbo to another 7psi does not provide the same hp or fuel needs, your statement is overly simplistic and I have to belive there is more to the story than you have posted.


the fuel will not be distributed evenly and you cant just go for big power with this kind of setup or you'll just blow up! and FYI i get those numbers from maximum boost.....
If you read the post you'd see that his plans aren't for big power. He said he was shooting for 180-200 and that is doable for what he is talking about.

OdessitPashka
09-28-2004, 10:10 AM
the numbers out of the book were not just created by someone who was bored, they got those numbers by trial and error, so you should believe me and the book! and if you are not goin to take an advice unless i have a turboed car then you should never come to forced induction thread at all because there is only 3 people that have turboed betas and they barely visit this website..... my car is waiting on oil lines and fans and will be turboed once I get a chance to install everything, so if you still think that im not educated enough to give advices to people then just ignore me....

he's not goin for big power then he should not be worried about anything! but he can reach those powers with less than 7psi!

Madhatter
09-28-2004, 10:46 AM
well just to clear up some of this talk about limits with additional injectors....

what OdessitPashka is referring to is the limit of how much fuel you can spray effeciently with just a single injector into the TB. Since most of the single additional injector set ups just put a injector before the TB and plenum, they are not evenly dispursing the fuel into all the runners at any given amount of boost. It might work fine up to say 7 psi as you say, it might work fine even more/or less. But the fact is, setting it up this way is not the best and it definately does have its limits.

If you plan to retain your stock ecm and would like to go with an additional injector route, do it the right way. I myself am mounting an additional fuel rail with 4 supplementary injectors to my IM on the runners, where it will be most effecient. In doing this the 4 primary injectors will be using the stock ecm maps so cold startups, idle, and different conditions the stock computer will still take care of. When boost kicks in merely adjust the supplemntal injectors for added fuel delivery. Simple as that. I am still having my 4 primaries piggybacked as well as the additional injector controll... so i will have full controll across the board.

dmdicks
09-28-2004, 10:49 AM
I'm running a 5th injector setup and am currently at a safe 15psi, with ZERO lean conditions being experienced. I think a lot has to do with how fine a mist the injector sprays. Its no different than spraying nitrous.

Madhatter
09-28-2004, 10:57 AM
I'm running a 5th injector setup and am currently at a safe 15psi, with ZERO lean conditions being experienced. I think a lot has to do with how fine a mist the injector sprays. Its no different than spraying nitrous.

you must have controll of your primaries then!! lol. Dont get this dude all excited thinking he can run 15 psi on a single supplementary injector with a mere aic.

2GTS
09-28-2004, 11:37 AM
the numbers out of the book were not just created by someone who was bored, they got those numbers by trial and error, so you should believe me and the book! and if you are not goin to take an advice unless i have a turboed car then you should never come to forced induction thread at all because there is only 3 people that have turboed betas and they barely visit this website..... my car is waiting on oil lines and fans and will be turboed once I get a chance to install everything, so if you still think that im not educated enough to give advices to people then just ignore me....

he's not goin for big power then he should not be worried about anything! but he can reach those powers with less than 7psi!

If you're quoting maximum boost I believe you. But how are we supposed to know where you are getting you info from when you give these overly simplified response like "7 psi is the max". If you gave a reason why 7 psi is the max I wouldn't question you unless your reasoning is off. I'm sorry if I offended you or questioned your knoweldge but the way you present your smarts makes it look like your pulling numbers out of your ***. I do ignore half the stuff you post because I know some of your info is off. The reason I'm posting this is so others won't think you're some pro, because you're not and neither am I for record.

FordFasteRR
09-28-2004, 12:34 PM
well, i'm glad that we all agree that the problem is not the 5th injector itself, but rather the possible distribution problems that it poses.

as far as i know, the 5th injector setup would work perfectly as long as you had equal distribution.

only1db
09-28-2004, 01:01 PM
alpine runs a fifth injector and they dont have any problems with their kit....and people are running pretty good over 10 pounds of boost :cool:

OdessitPashka
09-28-2004, 01:03 PM
I never said I was a pro, but before I say something I have someones opinion or some facts to back up my information. I do make mistakes because no one is perfect, but most of the time my information correct because I spend a lot of time looking at other people's experiences and ask them questions how they got such results.

i believe alpine has a very lean spot when the turbo is spooled up all the way and the fuel is still not there.

dmdicks
09-28-2004, 01:39 PM
Actually I am running the Alpine turbo kit which in its base form using a 5th injector and the OEM primaries runs just fine at 12-13psi. I've since added 290cc primaries for the added boost.

only1db
09-28-2004, 01:43 PM
dm....i have heard a lot of people talking smack about the unichip...how does it acutally work?? i'm torn between alot of things!

FordFasteRR
09-28-2004, 01:48 PM
dm....i have heard a lot of people talking smack about the unichip...how does it acutally work?? i'm torn between alot of things!


let me pose as DM here for a minute...

fuel distribution should be basically the same at just about any boost level, there might be slight variances but the difference from 7 psi to 10 psi as far as cfm is really not so big...

I would say that if the 5th injector works properly at 7 psi, then it should work properly at 10 and 15 + .. because what we are looking at here is an increase in pressure and only very slight increases in cfm...

I dont see how a slight change in pressure (+/- 10 psi should make such a big difference in fuel distribution..

I've spend a lot of time stearing into the TB opening of our manifold and there does not seem to be any real big problem as far as interference or bad runner design.. I would say that if it works with the alpine kit at whatever psi they set their turbo at then it should work on any other similar turbo setup on our cars. :)

I say GO FOR IT ! :)

Madhatter
09-28-2004, 04:39 PM
Actually I am running the Alpine turbo kit which in its base form using a 5th injector and the OEM primaries runs just fine at 12-13psi. I've since added 290cc primaries for the added boost.

does the alpine unit alter the fuel coming out of the primaries??

GLS2WRX
09-28-2004, 05:28 PM
let me pose as DM here for a minute...

fuel distribution should be basically the same at just about any boost level, there might be slight variances but the difference from 7 psi to 10 psi as far as cfm is really not so big...

I would say that if the 5th injector works properly at 7 psi, then it should work properly at 10 and 15 + .. because what we are looking at here is an increase in pressure and only very slight increases in cfm...

I dont see how a slight change in pressure (+/- 10 psi should make such a big difference in fuel distribution..

I've spend a lot of time stearing into the TB opening of our manifold and there does not seem to be any real big problem as far as interference or bad runner design.. I would say that if it works with the alpine kit at whatever psi they set their turbo at then it should work on any other similar turbo setup on our cars. :)

I say GO FOR IT ! :)

Hey Ford,

I've only started working with turbo's in the last 3-4 months but from what I have seen on dyno's there is a huge difference between 7psi and 15+psi, I would think it's not a very safe way to go with an extra injector and hope there's enough fuel being delivered. By the way how is this fuel being controlled? is this 5th injector just spraying a set amount of fuel all the time? If so, then when you aren't hitting any boost you must be running pig rich. What about timing? how are you guys that are turboed controlling the spark timing?

FordFasteRR
09-28-2004, 08:26 PM
dude, the 5th injector has to be actuated by a controller such as the ones described earlier on this thread.

and the amount of power is not "huge" ...

from 7 to 15 psi is only about 50-75 more hp...

GLS2WRX
09-28-2004, 09:49 PM
ahhh ok. so you do have a controller. I guess it depends on what huge means to you... to me a 50-75 hp gain is huge. Look at mustangs the v6 makes about 190hp and the GT makes 260 (not too sure about this)that's a 70hp difference (I know the torque difference is even bigger) if you run them side by side at the 1320 the difference will be huge between the two. And i ask again how are you guys controlling timing? The Hyundai world really needs to get behind someone to fine tune the ecu after a turbo install. I think it's just too damn dangerous. Maybe it's because I've been watching too many dyno tunes lately and when you hear an engine start pinging after a slight increase in boost it's scary. I'm talking about increasing boost from 14psi to 16psi, that's only two psi. I've seen engines go extremely lean from this small increase

FordFasteRR
09-29-2004, 09:09 AM
that is a good point you made about going lean..

My suggestion to prevent that kind of situation is to add a cushion of about 20-30 % more hp capacity into your fuel system upgrades. In the event that you lean out a bit, you still have room to increase the injector pulse and get more fuel out of it without having to upgrade the injector again.

so if you guesstimate that you will make 100 extra hp, then factor in + 20-30 % and get a 5th injector that can flow 130 hp.. now you have the room to grow in case you want more boost or if you just run lean for some reason.

:)