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Seemingly lack of available injectors and a DIY fix?????

Posted: Fri Jan 09, 2004 5:49 pm
by boostjunkie
Found some interesting information here:

http://forums.nasioc.com/forums/showthr ... did=478921

Can this be done to our injectors with the same results? I'd love to have some ~600cc injectors for my car!!

"Its a tough choice on which injector to buy for your WRX. Buy STI Pink injectors? $300-$550 and you get an extra 100cc worth of fuel. PE 650 or 850's? $600-$800 a set and because these are mechanically slow you need tuning or a flash to make them work correctly. Other companies sell an option for $450 and another that requires you to solder in a resistor pack. You can skip all of this and make your own 740CC injectors for free.
The Stock Blue 440CC injectors and the STI pink 540s are identical other then the end cap and the color so either injector will work for this mod. There is no advantage to having the Pink STIs once modded so sell them, Make some cash and mod your stock injectors. There are a few ways to accomplish the mod but what needs to happen is the end cap of the injector needs to be removed. You can grind it off or cut it off. Does not matter really. You can use a band saw or a dremel tool and a vice. Take your time and cut the silver end cap off where the nozzles (holes) are.
Since you are removing the end cap you dont need to send these off to have them matched. There will be no adjustment a injector shop can do anyways since they are sealed units. What you are doing is removing the flow restrictor (end cap). The biggest advantage is that the stock ECU is calibrated for the correct opening time compensation for these injectors (dead time). PE's are twice as slow and need more dead time. All of the issues that the PE's bring to the table are absent with these injectors.

Questions:

How much will the injectors flow once modified?
740-750CC

What about the spray pattern?
You end up with a find disk pattern

What about the idle?
Rock solid idle as stock once AFR's are tuned.

What about reliability?
They are stock Denso injectors and you are just removing the end cap containing the sized holes.

Do I need a fuel pump?
Yes, Pressure at the injector is reduces since the injector body can now flow more fuel. You need a fuel pump capable of handing 740CC injectors. Walbro is fine.

What if I dont have engine management will these work on a stock ECU?
NO, You will nearly double the fuel flow so you will need a Utec, SAFC, Link, Gems, Flashed ECU or other EM to calibrate these injectors.

I am still worried about equal flow. How Can I be sure this works?
You can send the injectors To Venom performance in California or RC engineering for testing once the mod is complete. Venom will even do the mod for you and test each one but the cost is nearly $300.

Why are you posting this information and not selling modified injectors?
Because it costs nothing to do this mod and its better to give back to the community. If you do not want to perform this simple mod yourself there are companies out there that will take your $200-$300. Maybe one of the members will try this, report back and offer to mod your injectors for a reasonable price? $50? This way its worth his time to do it and you save a ton of cash in the process by not having to spend $450+ on injectors. Work as a community guys

How many cars have you tuned with these injectors and how long have people been running them?
Kingpin has tuned 7 cars with these modified injectors. All idle smooth, All run fantastic and all have low IDC's One customer has 5000 miles on his set now with out issue.

Hope you guys try this and report back. I would not suggest something that I do not believe it. Some of you can flow test them if you wish and let us know the results. Let the flood gates open!"

Posted: Fri Jan 09, 2004 5:56 pm
by morgie
this is for +'02 WRX top-fed injectors. may not be applicable for ej22t ones, since they have a different tip.

Posted: Fri Jan 09, 2004 6:01 pm
by mTk
I believe our injectors don't have the perforated cap that the wrx ones have.

MK

Posted: Fri Jan 09, 2004 6:07 pm
by boostjunkie
CRAP!! Anybody know for sure? Gonna look for pics of our injectors . . .

Posted: Fri Jan 09, 2004 6:41 pm
by vrg3
Wow! Go Kingpin!

I guess in the present day Subaru decided to cut costs by essentially making one type of injector and putting different restrictors on the end to match the various requirements. I would believe it if that were a recent development, though.

mTk - Are you talking about the EJ22T injectors? Cuz there are three other types of injector that Subaru put on BC/BFs: the 90-91 NA 5MT ones, the 90-91 NA 4EAT ones, and the 92-94 NA ones.

Posted: Fri Jan 09, 2004 6:44 pm
by vrg3
Hmm, the pintle-nozzle ones (90-91 4EAT) don't seem to have a cover:

http://www.main.experiencetherave.com:8 ... P_2522.JPG

Posted: Fri Jan 09, 2004 7:26 pm
by boostjunkie
So it's back to square one.

Posted: Fri Jan 09, 2004 9:17 pm
by magnux
Not necessarily, does anyone know if the JDM WRX injectors have the salt-shaker cap? If so, we could mod those and install them.. we'd be out the cost of stock JDM WRX injectors, which is better than the the aftermarket ones. :)

Posted: Fri Jan 09, 2004 10:41 pm
by mTk
I know that my 92-94 4eat has the pintle style. Have to check out the 22t

MK

Posted: Fri Jan 09, 2004 11:08 pm
by vrg3
From what I know:

90-91 4EAT non-turbos have pintle-type injectors, part number 16611AA090.
90-91 5MT non-turbos have ball-type injectors, part number 16611AA120.
92-94 non-turbos have pintle-type injectors, part number 16611AA310.
All turbos had ball-type injectors, part number 16611AA150.

90-91 injectors are shaped a little differently from 92-94 injectors, and the fuel rails are shaped differently to match. All turbos use the old-style shape.

Huh. I just realized something. 90-91 5MTs and all turbos have Hitachi engine management (the ECU and MAFs are made by Hitachi), and 90-91 4EATs and all 92-94 non-turbos have JECS/AECS engine management. Wow! So I guess the easiest way to determine which a car has is to look at the MAF sensor. Silver means ball-type, plastic means pintle-type.

Posted: Fri Jan 09, 2004 11:14 pm
by boostjunkie
So what you're saying is that my 97 2.5GT has the pintle-type injectors that would support this modification? If that's the case, then I also have the fuel rail with those injectors to try this out.

Posted: Fri Jan 09, 2004 11:17 pm
by vrg3
I don't know anything about BD chassis injectors. :)

We also don't know when Subaru started using these types of injectors.

If you have the injectors from your GT lying around, it would be easy enough to pull one and take a close look at the tip. If you see the valve directly, then you can't do anything, but if you see a microwelded cover then that's a good sign. :)

Posted: Fri Jan 09, 2004 11:20 pm
by vrg3
Oh wait. I see what you were saying -- the GT has a JECS/AECS ECU.

It's definitely a completely different ECU design from 90-94 JECS ECUs though.

Posted: Fri Jan 09, 2004 11:24 pm
by evolutionmovement
I guess my 90 5MT is the most compatible car to drop a turbo in, then.

Steve

Posted: Fri Jan 09, 2004 11:29 pm
by vrg3
Heh... Just replace your Hitachi ECU with another Hitachi ECU, and your Hitachi injectors with another set of Hitachi injectors... But you get to keep your Hitachi MAF sensor. :)

Posted: Fri Jan 09, 2004 11:36 pm
by boostjunkie
lol! confusing.

I'll have to take a look at my engine sometime (if I can get in touch with my mechanic who's been MIA for a few months).

Posted: Fri Jan 09, 2004 11:42 pm
by evolutionmovement
vrg3 - you know how old cars get set in there ways, having Hitachi stuff wouldn't upset her as much as changing to something completely different that she'd then have to get used to.

Steve

Posted: Sat Jan 10, 2004 4:54 am
by Legacy777
Damnit!! I thought I had some pics of the 92-94 injectors while they were out.

This is the best pic I have of the nozzle
http://www.main.experiencetherave.com:8 ... P_2497.JPG

Posted: Sat Jan 10, 2004 4:58 am
by vrg3
Steve - That's actually true in some cases... Sometimes you'll take an old machine apart and it won't go back together. Or it goes back together but fails soon afterwards. I don't know if this is one of those situations though. :)

Josh - Yeah, I was disappointed! Well... only relatively speaking. I was really impressed by the whole photo gallery.

Posted: Thu Jan 15, 2004 8:18 pm
by Zate
question then ... if i have a 2.2T block .. what types of injectors can be used on it ? .. or is that determined by the intake manifold ? Can we use WRX 440cc injectors if we use a WRX intake manifold ?

Posted: Thu Jan 15, 2004 8:23 pm
by ciper
To use a WRX intake manifold wouldn't you also need WRX heads? If you used WRX heads wouldnt you also need new pistons? Its not that simple, unless you are referring to some overseas WRX that got the same style of injectors.

Posted: Fri Jan 16, 2004 6:15 am
by boostjunkie
And even then you'd need to swap the fuel rails, if you don't modify your existing one.

Does anyone have experience with RC engineering? Would they make a custom set that would have the same shape/mounting as the stockers? Or would they be able to modify some stock injectors with a higher flow rate?

Posted: Sat Jan 17, 2004 1:17 am
by Legacy777
I'd definitely say RC Eng are good.....no experience whether they can do what you're looking for though.

Posted: Sun Jan 18, 2004 12:41 am
by NICO
why dont u get the sti injectors? there the same ones, but yellow and they fit right in.

Posted: Sun Jan 18, 2004 7:58 pm
by ciper
Which STI?