Add-on fuel rail. Any one interested?
 

We are adding a custom 3rd fuel rail on the car. It sits between the upper and lower intake manifold and it can hold 4 top feed injectors. It will cost about $350 for the adapter plate and fuel rail itself. Anyone will be intersted in such thing?

Chuck Huang

http://www.rotaryextreme.com/refuel-1.jpg

Another photo:

http://www.rotaryextreme.com/refuel-2.jpg

Would one then run the 1st & 2nd in parallel as "primaries", with the 3rd rail being run as the "secondaries?
What sets of injectors are you thinking of using?

Interested.
Ken

It depends on what ecu you are using.

We use PFC and the injector driver is strong enough so we can splice the wire off the stock injector wiring harness. You just need to use high impedence top feed injectors such as those found on 2nd gen TII.

With PFC, you can run 2 injectors on the outside parallel to the secondary and 2 injector on the inside parallel with primary.

If you have an ECU that can run 3 sets of injectors sequentially, you can do so as well.

On the car, we already have 950 cc/min primary and 1300 cc/min secondary. So we are only adding one pair of 2nd Gen TII 550 cc/min injectors for high boost application. Those TII 550 cc/min injectors are very cheap used and we just send them out to RC Engineering to be cleaned for $25 each.

But if you have the stock 550 cc/min primary and 850 cc/min secondary, you can use 4 550cc/min injectors.
Add 4 550cc/min injectors will be the same as you are running 1100 cc/min primary and 1400 cc/min secondary. The total amount is 5000 cc/min. If you use the 550cc/min primary and 1600 cc/min combo, the total fuel amount is only 4300 cc/min.

This set up is for people who needs a lot of fuel or you don't want the hassle to change the stock injectors. As you can see, the installation is a lot easier. Also smaller injectors have better spray pattern and atomization. So it's better to use a few sets of smaller injectors than a single big one.

Chuck Huang

I'm wondering what you use for injector delay times with a combo of side & top feed injectors running off the same circuit? Perhaps it's not as critical because the side feeds would squirt something down there.

I'm also wondering, if you just used the secondaries on this rail might it still fit with all of the emissions air control systems in there?

As for injector lag time, you have to find out by tuning.

You do have to remove the ACV and use a block off plate.

Chuck

OK!
I'm running a Wolf...

I am Quite Interested now.
I'll be sending a PM.

Thanks!
Ken

Hey Chuck,

I think when the time comes to upgrade fuel I would be very interested. that fact that I can run closer in size injectors for a smoother transisition helps.

Can you tell me what the difference is between using this, and just getting the greddy elbow with the additional injector bungs?

The greddy elbow has the injectors in the wrong place , in front of the throttle body .Any girl knows that .

This fuel rail supplies fuel to each intake runner with indepedent injetors.

Greddy elbow has injectors before the throttlebody and the fuel distribution into the intake runner is unknown. Let's say I blew up my motor using those and additional injector controller 10 years ago. At that time, there was nothing else available. There was no PFC and no Haltec, or any kind of standalone computer. At least I wasn't aware of anything at that time. The only thing I knew available was Motec which costed $5000 and back then a poor college student such as myself could not afford.

Greddy elbow with injectors holders and Greddy Rebic III were the only thing you could do to richen the fuel mixture back then. No one uses that anymore. I still have those antique sitting here.

Chuck Huang

if you are in that much need of fuel, wouldnt you want to upgrade the intake anyway? i have seen these plates available for years now, they are nothing new. what i havent seen though, is many high HP cars running them... not saying they wont work. just wondering if you have any examples of cars that are running with the best of them using this.

I think its a sweet idea, but isnt the fuel going to spray straight onto the other side of the plate and then just DRIP down in the engine, I dont think that could be very reliable...

I agree to part of this, but not all of it. I will unless chuck can't prove this is really needed.

I think its little to much fuel to be running. On the other hand its a very easy install if you dont want to upgrade your other injectors. Also Chuck says it helps with tuning because smaller injectors spray better.


So Chuck please show us something to show that this is a good mod.

*thinking*
Also it might be cheaper to just add this one rail, at only $350, whereas paying for 2 new upgraded rails and injectors to get more fuel. So just by adding this one rail you wouldnt even have to upgrade anything! This is a great buy!
hmm...

But I still would like to see some proof that it is easier to tune and can handle high #s.

You including new fuel lines to hook it into the stock rails or should people plan on setting up Y adapters going to AN fittings?

You mean an upgraded intake manifold?

In Japan, they do have an aftermarket cast lower intake manifold to hold 2 sets of injectors instead of one. But that thing is sold for about $1200 and you can only add 2 injectors. I think they are getting idea of the 6 port RX-8 which has 3 sets of injectors.

Revolution Motorsports uses this type of fuel rail. It's quite popluar in Japan. I believe their road race car has 500 rwhp with a T78.

I will post some photos of the article when I get a chance.

Chuck Huang

That's what I thought at the beginning but after I see them used on Japanese race cars, I decided to get one and going to test it out myself.

There is nothing for sale at this time. I am going to test it out myself first. This post is mainly to gauge some interest.

Chuck Huang

To use this fuel rail parallel with the stock fuel rails, you do need to use it with an aftermarket fuel pressure regulator unless you can tap some fittings onto the stock one fuel rails.

So the outlet from the primary will go into this fuel rail and outlet of this fuel rail will go into the secondary and you will use the stock fuel pressure regulator which is attached to the secondary fuel rail to control fuel pressure.

There are many ways you can lay it out, depending on how much your budget is.

Bigger injector has worse spray pattern. Just like you can't really use 1600 cc/min injector on the primary fuel rail and expect a good idle.

Chuck Huang

On my own car, I do the following way because I am lazy and I have a aeromotive fuel pressure regulator laying around. I don't feel like taking out the primary and secondary fuel rail and tap them.

I put a T to replace the rubber hose that goes into the primary fuel rail. One end of the T goes into the primary fuel rail hard pipe and the other end goes into the 3rd fuel rail. The aeromotive FRP has two ports so the secondary fuel rail and 3rd fuel rail all return back the FPR and one single return back to the hard pipe. That way I can use single FPR to determine the fuel pressure.

$350 does not include those lines. If want a drop in kit like mine, it can be done. The cheapest way will be tapping the stock fuel rails and use the secondary as the final rail but takes longer to do and more work.

Chuck Huang

Dragon used this on his last few 13B engine's before going 20B. If memory serves me correct, he ran his injectors as follows: Primary 550 X 2, no "secondary" rail(plugged injector holes) , this style injector holder with 1680 x 2 on the outside 2 injectors and 720 x 2 on the inside ones. Then fuel was routed with dual walboro's with one pump for the primary and another pump for other rail.

Reason for so much fuel? He was running 27 psi on a T-70.

i wasnt talking about Japan. i was talking about right here in our own backyards. ;) these manifolds have been around for many many years and have been proven time and again. and depending on your engine type, run between the ballpark of $300 to $350. if you want it in semi-PP it is available for slightly more...

using a LIM like this:

http://www.kgparts.com/images/Intakes/13btii.jpg

and the TBI will allow upto 8 injectors ontop of the 2 primary in the block for a total of 10.

http://www.kgparts.com/images/Intakes/web4brl.jpg

or the *old* setup of 6 injectors

http://www.kgparts.com/images/Intake...TB_adapter.jpg

:eek: ^^ That's some serious shit.. Whoever's using those setups isn't messing around...

hehe. those are made by you, right? ;)

So you are saying with the lower manifold and top manifold that comes with a throttlebody, everything for $300-350? If that's true, that is dirt cheap.

Can the stock piping bolt back on or you need custom intercooler piping to fit with the top manifold?

Do you have a picture of the bottom side of the top manifold. Do the injectors squirt into individual runners? I can't see too well with just those two photos.

Chuck Huang

ya i looked at these on the site, and was kind of confused, ive never seen these on an engine before.

do you run these rxrotary2_7? what are the gains?