Does anyone use sub-injectors?

[Doward]

If your tune is correct, you should have zero mileage difference between using 12 440s or 6 880s.

With good P&H injectors, using massive injectors at idle is much less of a problem.

 

[TheNewRed]

Very common in Japan !
That is why VPC ROMs larger than 550cc do not exist.
The Japanese will run 6 additional injectors on the lower manifold.
You do NOT need an additional fuel pressure regulator.
The additional injectors are fed off a line 'T'ed into your line feeding the fuel rail.

Two stock 440 injectors, feeding into the pipe in front of the throttle is equivilant to 6) 585cc injectors.
GReddy even sold modified pipes, that already had the 2 extra bungs welded in.
Six stock 440 injectors with your stock 440 injectors is the same as 6) 880cc injectors, or enough for MegaBoost !

The real sweat part of using additional injectors is that normal driving, they never come into play.
They are on a seperate circuit, that only comes on during boost conditions.
So they normally provide better mileage.

Thanks for the back up my man!:evil2:

 

[7M-fanatic]

If your tune is correct, you should have zero mileage difference between using 12 440s or 6 880s.

With good P&H injectors, using massive injectors at idle is much less of a problem.

But still a problem.......
If you have a minor mis-tune with main 880s, the problem is much worse than with 440s (greater percentage of total fuel delivery).
And using additional injectors, where you decide what RPM, or boost level where they actually come in, is much more forgiving than trying to do it all with big injectors.

 

[TheNewRed]

But still a problem.......
If you have a minor mis-tune with main 880s, the problem is much worse than with 440s (greater percentage of total fuel delivery).
And using additional injectors, where you decide what RPM, or boost level where they actually come in, is much more forgiving than trying to do it all with big injectors.

See this is the theroy that got me started on the subject, this is what i figured.
440cc x 6=2640cc of factory fuel flow... now for whats typicaly needed...
550cc x 6=3300cc's of fuel flow, so your getting a plus of 660cc of fuel flow with 550s (or 110cc per cylinder)
So why not get two 330cc injectors, or better yet 350cc injectors(to have a little to play with) and be done with it?:icon_bigg

 

[TheNewRed]

one other question, i have seen sub's placed anywhere from 12inche s and closer to the throttle bodie inlet, and even sandwhiched between the head and intake(Hahn portfuler), but if i were to place 2 injectors right b/f the throttle bodie would it be consistant throughout all 6 cylinders namely 4-6?

 

[foreverpsycotic]

I think the only person contemplating running more than 6 injectors would be Slow66. 14 1600cc injectors is what I think he is going to be running. Then again, his turbo feels like it weighs 1/5 of my body weight and looks to be able to swallow a teenager.

 

[GrimJack]

Folks, please keep in mind that this is old technology. The cost of a AIC, the extra injectors, all the mounting, wiring, etc, is going to be well over just purchasing a set of 6 larger injectors.

The only way I would recommend that anyone go this route is if they get a spectacular deal on the parts - AND that they are still in good condition. AFAIK, nobody actually makes these anymore.

PS: There's a reason for that...

 

[TheNewRed]

Folks, please keep in mind that this is old technology. The cost of a AIC, the extra injectors, all the mounting, wiring, etc, is going to be well over just purchasing a set of 6 larger injectors.

The only way I would recommend that anyone go this route is if they get a spectacular deal on the parts - AND that they are still in good condition. AFAIK, nobody actually makes these anymore.

PS: There's a reason for that...

My good sir, i dont believe you read the ENTIRE thread, the greddy e-manage, that im purchasing soon can control up to two additional injectors, w/ just 2 factory GTE injctors and this http://www.rossmachineracing.com/dualinjassm.html (and of course a few AN lines and fittings), i will be well UNDER the cost of a set of brand new RC's, and since there arent a lot of people here or that i know running a set of subs on a GTE, it will be to say the least an eventful and unique adventure.

 

[GrimJack]

Trust me when I say I've read the entire thread. Furthermore, I know of several examples of this being done with extra injectors - the picture I posted wasn't something I found on the net, I *took* that photo, and the guy who drives the car is a local.

As for the costs, here is my spreadsheet:

Emanage - $300
Wiring harness - $35
Injector assembly - $100
Injectors - $170
Injector clips - $20
Pipe & welding for the injector assembly - $$$
Total: $625+

or

Lexus AFM - $100
550cc injectors - $510
Injector clips - $60
Total: $670

The costs are a lot closer that I thought they would be - likely because of the Ross Machine Racing parts, the old Greddy / HKS parts for this were a whole lot more money, as I recall.

Don't get me wrong, I'm not saying it can't be done, or even that you shouldn't be going this route. All I'm saying is that, in my humble opinion, a set of brand new larger injectors is the better option.

 

[TheNewRed]

As for the costs, here is my spreadsheet:

Emanage - $300
Wiring harness - $35
Injector assembly - $100
Injectors - $170
Injector clips - $20
Pipe & welding for the injector assembly - $$$
Total: $625+

or

Lexus AFM - $100
550cc injectors - $510
Injector clips - $60
Total: $670

The costs are a lot closer that I thought they would be - likely because of the Ross Machine Racing parts, the old Greddy / HKS parts for this were a whole lot more money, as I recall.

Don't get me wrong, I'm not saying it can't be done, or even that you shouldn't be going this route. All I'm saying is that, in my humble opinion, a set of brand new larger injectors is the better option.

I appreciate your opinion but $170 for two factory injectors??? They are being sold for $30 for all six on SM, and various prices on ebay, i also tig weld(im in the process of building a FFIM), and as fo the e-manage im not getting that just to control the subs im going to use ignition,and injector harnesses, and pressure sensor .... i was looking to replace $500 worth of injectors with $150 for two factory ones and the RMR holder. Im in college so im trying to go the more efficent route(money-wise), and after reading all of the instruction booklets for the e-man., i dont even think ill swap out the stock MAF.... what do you guys think, thats predominatly what the e-man. can be used for...how far could i push the factory unit??:icon_bigg

 

[TheNewRed]

Lexus AFM - $100
550cc injectors - $510
Injector clips - $60
Total: $670

And my biggest problem with this setup is there is no way to tune it(if you just buy whats on your list) so you might as well throw in the cost of a SAFC or some other fuel computer.....but with the eman. thats really all i need for the power levels im trying to reach, therefore i would say my route is more efficient, has more options/ability, and ultimately :naughty: CHEAPER:naughty: .

 

[buldozr]

And my biggest problem with this setup is there is no way to tune it(if you just buy whats on your list) so you might as well throw in the cost of a SAFC or some other fuel computer.....but with the eman. thats really all i need for the power levels im trying to reach, therefore i would say my route is more efficient, has more options/ability, and ultimately :naughty: CHEAPER:naughty: .

Thinking out of the box are you, having the old folgies smight thee??? j/k, im glad someone is thinking out of the box, good luck on your setup, and remember this VERY IMPORTANT STATEMENT: their is more than one way to skin a cat and just like most math problems, many ways to get the same number(result). I could see one advantage off the bat, drivability would be like factory(bombing around town). Have fun with it!

Edit: I just remember about the 280z turbo kits by cartech, they used a pressure switch to open up the factory cold start injector for additional fuel, crude, but it worked great!

 

[Adjuster]

Thought this over when I was using the Eman Blue..

Run six 440's (Stock injectors) and also buy six weld on bungs, and six more used 440's and add them to the UNDERSIDE of the upper intake manifold where there is room. You will need to make a custom fuel rail, and if your using the Areomotive AFPR, just return the fuel to the unused port on that.. Supply is easy. Just T off the fuel line to the main fuel rail.

The additional ones would be batch fired 3 and 3, but at the point where you would bring them on line, it would not matter much at all. (The stock ones are batch fired two x 3, so it's not that much different.)

You end up with 880cc fuel for each runner, but in most conditions, only ever use the stock 440's...

Problem is this.
1) Welding. (Seems like you have this down.)
2) Injector bungs. (Never went very far on this, but they are not hard to make/have made...)
3) Fuel rail. (Sold in bulk, just have the holes machined at the right spaces, add mounting points, and your good to go. Supply on one side, return on the other..)

In my case, I've ditched the Eman and Profec E-01 for the Maft Pro. (More options, and no more AFM etc.)
And gone to 780cc injectors using the stock rail. (Should be plenty of fuel.)

These are Delphi injectors, machined to fit, so they are very reliable, and should give me no problems.

Also, the average guy does not notice the larger injectors... But it's not really an issue on my engine I suppose. Nothing looks very stock anymore.

 

[TheNewRed]

Thought this over when I was using the Eman Blue..

Run six 440's (Stock injectors) and also buy six weld on bungs, and six more used 440's and add them to the UNDERSIDE of the upper intake manifold where there is room. You will need to make a custom fuel rail, and if your using the Areomotive AFPR, just return the fuel to the unused port on that.. Supply is easy. Just T off the fuel line to the main fuel rail.

The additional ones would be batch fired 3 and 3, but at the point where you would bring them on line, it would not matter much at all. (The stock ones are batch fired two x 3, so it's not that much different.)

You end up with 880cc fuel for each runner, but in most conditions, only ever use the stock 440's...

Ok, sweet first off i never thought of this "Batch Fire" idea, sounds great but give my memory a reminder on the wiring of it. second if you had two 440s wouldnt it be 880ccs per runner? You definetly have it down and this is better then my idea b/c if one set failed the other set could be positioned to somewhat feed the other cylinders enogh to prevent a really bad case of leaning!! Tell me more, tell me more!!!!:biglaugh:

 

[TheNewRed]

Edit: I just remember about the 280z turbo kits by cartech, they used a pressure switch to open up the factory cold start injector for additional fuel, crude, but it worked great!

That sounds like a damn good idea also!!!!

 

[IJ.]

^ BZZZZZZZZZZZZZ WRONG

If it's tuned taking the 2nd set of 440's into account and they're needed it will be lean if you lose one on that cylinder and it WILL burn a piston.

If it doesn't need them all you'll do is make a horrible rich motor or if using some stupid cheap piggy back to take fuel out it will have an adverse effect on the timing map...

Cheap fuel control will cost you a motor sooner or later.

No no no no and NO using the CSI isn't a "good idea" it's crude cheap and stupid.

 

[Adjuster]

IJ's correct here.

Just because you have two sets of 440's for fuel, does not mean your ECU is smart enough to see a lean condition due to injector failure, and then bring one of the two injectors per runner up to fill the gap.

(To do this, you would need a stand alone, and wide band for each runner that allows closed loop fuel tune for each injector and WB feedback on that injectors exhaust flow. The TCCS is not capable of this as far as I know, and no piggyback that I know of is either. There are some stand alone computers that should be capable of this type of fuel management, but tuning it would take some know how, and time.)

Anytime an injector fails, under boost, your going to lose the piston most likely.

Coatings can help, but not prevent failure. (They extend the heat resistance of the aluminum in the piston crown, but only extend the limits, not make it impervious to running lean.)

The reason I did not do the system I wrote up was cost and complexity. Too much of both involved.

Simple way is larger injectors, and use the fuel rail you have. Add in the Areomotive and ditch the J-Tube. Add twin Walbro's if you want, and your power goals are over 600RWHP.

Unless you have already bought the Eman, I'd reccomend going with the Maft Pro. (I have yet to wire mine up even, but there are many who have them, and they work great. And there is great support from guys like Dr. Jones on here too.)

Advantages to larger injectors, and the Maft Pro.
1) Newer injectors have improved designs. Delphi makes nice ones that are cost effective.
2) Maft Pro removes the AFM. (No more air meter issues. Speed density is simple, and reliable, and the sensors are low priced GM spec/sourced.)
3) With the larger injectors, I expect to see some headroom on fuel cut, and fuel cut can be adjusted by the Maft Pro as well. (Same with the Eman.)
4) Maft Pro can be wired up to your wideband, and used to closed loop control fuel, or also add a safe amount of fuel in the case of lean operation. (Part of the closed loop fuel tune options.)

Will not save a motor if the injector fails, but with the coatings, I'm hoping for some additional headroom if that ever happens.

Short of going to a full standalone, the Maft Pro is about as good a system as any out there for the 7MGTE/TCCS in my opinion.

Good luck either way you go.

 

[buldozr]

Cheap fuel control will cost you a motor sooner or later.

No no no no and NO using the CSI isn't a "good idea" it's crude cheap and stupid.

Im with you on the 'cheap fuel' statement

the csi idea is funny, a large aftermarket performance company exploited your wallet.... and you liked it!:nono:

when talking about the z's, I think the pressure switch was set to come on at 2-3psi and then would turn the csi on full boar. Yes very crude, yes very cheap, stupid.... negligible when talking about maybe 180hp to the wheels, negligible. Your 'cheap' is Cartech's 'thrifty'. :biglaugh:

 

[IJ.]

Anytime you add another layer of complexity like this you're increasing the window for failure.

By adding a second set of injectors you half the MTBF.

 

[TheNewRed]

the csi idea is funny, a large aftermarket performance company exploited your wallet.... and you liked it!:nono:

:

UMMM ok, well at first i thought that you all thought this was an ok idea(guess i was wrong) but im pretty sure its not as bad of an idea that you guys make it seem. look at the Hahn portfueler(also A LOT of SRT guys run subs) it has succeded for a good reason, not b/c of exploitation. You guys also make a big deal out of "failing injectors" i have never seen a case of this until i came on to SM, is it b/c they are Low imp. injectors or what, and by the way buldozr, no one has exploited my wallet, i havent bought the damn system yet, and if the product performs as it is advertised then it IS a good product(which it is), i havent seen a case of a greedy eman., getting a bad wrap b/c of it "failing", only b/c idiots dont know how to use the product.:nono:
Im simply debating my options, and thought i was onto something....and also im sick of MK3 guys ramble about 550s and lexus AFMs.....and the MAFT pro, just looking for more options and a somewhat cheaper approach!!!