Where to put the "slightly higher flowing injector"

[Legacy777]

I had the STi 550 cc/min side feeds flow tested & cleaned. One flows slightly more then the rest. What's your thoughts on placement of that injector? Cylinder 3 or 4? Other?


The Link does offer advance fuel injector adjustment on a per injector basis. So I could up or down an individual cylinder. However I don't know if that extra flow is the same from idle to 80% duty cycle. Without some in-cylinder or individual exhaust gas monitoring, it'd be hard to say.

Thoughts?

[douglas vincent]

#4

[Legacy777]

This is from your experience correct?

How many times did cylinder #4 go compared to any other cylinder?

[douglas vincent]

#4 went everytime UNTIL I reversed the fuel line feed, then #1 went twice.

Now I run a parrallel fuel set up.

[Legacy777]

How'd you reverse the fuel line feed? What did you do to the regulator, or were you running an aftermarket one?

[douglas vincent]

I can't remember WHY I reversed the fuel feed for the life of me.... But I simply put the left fuel rail on the right side, and the right side on the left. But I had to cut up the stock fuel lines under/around the manifold to make it work. The fuel regulator was now on the front of the drivers side (I think). Or maybe I moved it...

But when I went to parrallel lines, I just used two driver side rails and had them both get fed from a T, infeed and outfeed, with the stock regulator on the downside of the outfeed T.

[Legacy777]

I've got extra lines I could probably do a parallel setup....but I don't know if I really want to deal with that now.

[Imprezive]

Theoretically cylinder 3 would want the highest flowing injector. Thats wierd that cylinder 4 was the one to go.

I would assume 550's would be operating well within their range, so it wouldn't matter too much where you place them.

[douglas vincent]

Almost 90% of the blocks I have seen its been #4.

[BXSS]

+1 #4

#4 reads slighty higher EGT's than #3 on my OBS-t, I have a couple of EGT sensors!

I suspected this from day one even before the 2 pyrometers were on my single port motor because if you look @ the intake manifold #4 is the first cyl to get air after the t-body on the older cars.

[93forestpearl]

Josh, for an easier time making a parallel setup, Outfront motorsports has these nifty adapters

I modified this one to use on the FPR end of the rail, since the biolt spacing is different. It fits perfectly on all the other ends of the rails though. I've since found that you can run a 1/4 NPT tap into the FPR end to put whatever fitting on it that you desire.

[Legacy777]

Hmm....

I remember seeing these before. The fitting is a standard AN type fitting right?

What regulator are you running?

I'd kind of like to do this, but not sure how much room I have and if I can shoe horn more crap in there.

Dan, do you have any pictures of your completed setup?

[BXSS]

Nice adapter - that should make life easy.

I think Dan is running an Aeromotive FPR.

[93forestpearl]

Yeah, the fitting is a -6 AN. Outfront get's about $15 a pop for them. I'm using the Aeromotive A1000-6 FPR. The base pressue on it is adjustable from 30-75psi. I'd say I have about $300 into the whole setup, since the line and fittings ended costing more than the damn regulator itself, which is about $140 at Fullthrottlespeed.com.

That picture isn't how they go on the proper ends of the rails. The supplied Hex key bolts sit flush to the top of the adapter.

Since my initial setup used two passenger side rails, I had two factory regulators. I did't trust them so I did that setup. I had to put the adapters on regulator ends of the rails and thus elongated the bolt holes in the adapters to make them fit.


I'm at school a the moment and have some pics of my old setup on photobucket. When I get home later I can download what I have on my camera. My old setup had the regulator where the AC compressor was, since it fit there nicely. After a while, it made me a bit nervous because if I got in a front end wreck, there would definitely be a fire. I carry a fire extinguisher just in case. Right before the wreck two weeks ago I reworked the lines and everything to move the regulator the where the ignitor is. The lines were more equal in length from doing that too. Sadly, I got to drive with it for about two hours before the incident.


Anyways...














I used that basic 5/16 brass T to split the feed. I ran normal fuel injection hose to the rails, and the braided from the rails to the regulator. On the bottom of the regulator I used a 90° -6 to male 1/4 NPT, and a brass hose end on that to go to the return. There are definitely other ways to do it, and I surely didn't make it optimal. Hindsight is always 20/20 though. Next time around I'll get a splitter that doesn't make the fuel do a hard corner. Also, if I were to do it all over again, I wouldn't use braided. I'd use the Socketless stuff instead. Easier to work with and actually lasts longer, apparently, since the braided stuff gets dirt under the braid and it grinds on the liner. I haven't had any troubles though. If you do used braided, DO NOT get Earl's hose ends. They are the biggest PITA to work with. Aeroquip is where its at, as they are a breeze. Plus they are made here in MN, .


I'll get those other pics up when I get home from school

[Legacy777]

Very cool setup Dan!!

The problem that keeps running through my head is....where the fuck am I going to put all this stuff. There's just no more room in the engine bay.

I'll think on it. I may just get the Link in, see how things go, and where that takes me. I could kill a tranny....a motor or who knows....then it'd be time to build for much more power. Right now, it's built with stock internals, and not really for a super horsepower build. Even if I have to redo things, I figured with all the swap stuff, I'd stick with stock to get everything up and running first.

But I'd definitely be interested in the new pics.

[93forestpearl]

My camera battery is charging right now. Damn crappy Cannon batteries.



My buddy was running 650's in series with an Ebay FPR just fine. That was good for 22psi on his GT3076R. There was no major variances in the carbon buildup on the pistons when he went through the motor.

[Legacy777]

That's good to know.....and I kind of figured that. People have asked what boost am I going to run, how much power am I planning for. It's going to make what it's going to make and still be safe & reliable....at least for now.

So we'll see.

[93forestpearl]

Here are the new pics. I was going to have to get rid of that brass 90 degree bend on the end of my rail because I hit a fuel wall at about 17psi. With larger injectors. The blue AN bend on the rail is one I threw on the rail off my EJ25D just trying it out. Next time I'll be sure to use smooth radius fittings and not the crappy brass stuff.














And the EJ25D rail with 90° 1/4 NPT to -6

[93forestpearl]

That's good to know.....and I kind of figured that. People have asked what boost am I going to run, how much power am I planning for. It's going to make what it's going to make and still be safe & reliable....at least for now.

So we'll see.

Ya, for what you will be doing initially, you won't really have to worry about it. When you get into the 700cc/min+ territory, it becomes more of an issue.


When you get to the point of going much bigger in the power department, your AWIC probably won't be in your best interest, so going to a FMIC will probably open things up a bit for you.

[Legacy777]

I love my AWIC

Is it just restriction issues going through the AWIC?

[93forestpearl]

^ You hit the nail on the head. Once you get to enough airflow capability, it will become a bottleneck. Just like the 22T heads. You might gain some hp switching to higher flowing heads, but the stock VF11 is the most restrictive thing in the system at that point. In my case, I should pick up 40-50whp with the EJ25D heads I am puttung on.

You could go to something like this: (referring to the AWIC)

[Legacy777]

Yeah that would be a possibility.

I guess it all depends on how much further I intend to take this car. That is really the big question that I can't answer now...

[93Leg-c]

I had the STi 550 cc/min side feeds flow tested & cleaned. One flows slightly more then the rest. What's your thoughts on placement of that injector? Cylinder 3 or 4? Other?

From my experience, I echo Doug's advice: #4.

[Legacy777]

Thanks guys.

Number is where it will go.