I've been working on this 8 injector setup since december. I know some people are interested, so I'll give you another update. I finally put an 8 injector manifold on my car last thursday. The FPR I bought wasn't holding its settings, so I had to buy another. That will go in tomorrow (27th). After I get stable fuel pressures, I can start tuning. My present manifold houses 8 252 cc/min Accel injectors. 4 in the stock location controlled by the stock ECU and 4 near the bend in the lower manifold. The extra four are mounted in aluminum tubes epoxied into the manifold. 2 '96+ fuel rails are used in series with a single bypass FPR. I'll write a complete instruction set when I finish everything. So far so good...

Here's a pic




Corbin

'95 ESI-T
HRC+FMIC+ETC...

Glad to hear progress is coming along good on your project, Corbin. We are always entertained by reading your findings, or atleast I am. The manifold looks real good :-)

its looking good corbin... its cool when you make something...
thanks for all the help

Michael 99gs
Boost It!
Mods:
no time to put in yet: s-fmu,injectors, and crane ignition.
Hrc Stage 2
Greddy Type S Bov
VC-2
Road Race Catch Can
Greddy Profec B & Switch
Apexi WS Catback
Super Afc
Autometer Boost,
Egt
Air/Fuel Light & Digital
Tokico Adjust Struts
Eibach Pro Kit Springs
Front & Rear Upper Bar
CarCraft Interior
Sound System= Bring it On

why don't you use bigger injectors than using eight?
this is a question not a comment. i want to know.
later
"Z"

Im not really sure but I would think that because he's using 8 injecters that the ECU can control, hes getting the same amount of fuel that big injecters would give, but without some kind of standalone fuel management system.

What will power these other 4 injectors, electrical wise???

I'm jumping in my seat as we speak. Now I just need a little cash. The reason he's using the 8 instead of 4 is b/c of the drivability. He (and I) believe that you can achieve the great gas mileage of just 4 injectors while not boosting and then when you do boost, plenty of fuel for the time that you need it to keep things safe. Hey Corbin, why the Accel set-up and not the stock 230 something injectors?

well corbin is auto and he found that when using larger injectors and the safc it wasnt quite the way he wanted it. he said something about it bogging down alot and knocking on hills, because he cant control the gears. but then also i have heard that dino blew his motor because the safc lost his maps. but i don't think he knew that. but the extra injectors are run by an extra injector controller. and i too must say good job corbin i can't wait to see how it turns out ya genius!

Dino didn't blow his motor because the afc failed. He was just running lean (or so we suspect). As far as the 8 injector setup, having larger injectors only work so far as the afc combined with your stock ecu. Meaning unless you go with stand alone fuel management you will always be limited by the size of the injector that the afc and your ecu can tag team. Now with an 4 + 4 injector setup you will have 4 controlled by your ecu. This will be your normal fuel map that the car has stock so your idle and regular off boost driving will be normal. The extra 4 will be controlled by an AIC (additional injector controller). This will control the amount of fuel the extra injectors spray. Mostly this will be for on boost applications. It just seperates the two because it'll be easier if you don't have to worry about regular off boost fuel delivery and just tune the AIC for on boost. Or you could just get a whole stand alone fuel management system.

I got a S-AFC now. It's not in the car, should I keep it and use it as the AIC? I'd imagine that it would do the job, but I'd like to know that before I give this a try.

I don't think that would work because the afc just modifies the map sensor voltage a certain % and then the ecu controls the fuel from there. I think you would need an actual controller. I think someone posted a link on here once before.

I'm using new Accels, because I'm all about precision. I needed a guarantee that each injector would flow exactly how much it was rated for (within a couple percent). The only way to do that is to buy new, quality injectors or send you stockers to RC Eng. It was only slightly more expensive and much more convenient to buy new injectors.

I forgot to mention what controller I'm using. I'm using an O34 Supplemental Injector Controller. It is a universal item, so you have to do alot of work to properly set it up. I have already made up a wiring diagram to help those who follow me. The controller interfaces with a laptop and is pretty user friendly. My big problem is figuring out my preliminary settings. There are a bunch of variables that you can change, but it doesn't tell you how they interact to supply fuel. I guess it comes down to some experimentation. Luckily I have a datalogger too.


Corbin

'95 ESI-T
HRC+FMIC+ETC...

Hey Corbin, which AIC are you going to be using with your setup?

so with this 8 injector setup would it allow you to boost higher on pump gas since you can supply more fuel? what if you put 8 bigger injectors to flow better for higher boost.

I'm using this controller specifically:
http://www.034efi.com/034SupECU.html
It is a universal item. It can run any injector on any boosted engine.

My issue with the S-AFC is it alters the MAP input to the ECU. I think this throws off the calculated load on the engine. I think the ECU determines spark timing based on load (among other things). With the 8 injector setup, there is no "fooling the ECU". The ECU gets all the proper sensor inputs and determines the proper way to run the car. When you want more fuel, you add it using the extra injectors. I think it is a good alternative to the stand-alone system. Not as powerful, but easier/cheaper to implement and better than a S-AFC. One cool thing is you can run stock injectors as primaries and huge injectors as secondaries without any driveability probs.

>so with this 8 injector setup would it allow you to boost higher on pump gas since you can supply more fuel? what if you put 8 >bigger injectors to flow better for higher boost.

I don't think fuel is limiting boost on pump gas. I think timing is what limits your boost on pump gas. Your timing will remain at stock specs until you change them. If you run into problems, you'll have to add some sort of ignition upgrade to retard timing.



Corbin

'95 ESI-T
HRC+FMIC+ETC...