I understand the function of the FJO, Its just a resistor box. What's bothering me is this 850/1680=0.50 and 850/1000=0.85 you can only input one or the other, so if the 1000cc is running 85% duty cycle does it mean the 1680cc is running 50% duty cycle or one set of secondaries are running right and the other is not?

 

I'm not aguing this wouldn't work, but I wonder if it's a good idea to send 1550ccs of fuel into the primary intake runners/ports and 1680ccs of fuel into the secondaries. I don't have enough data to back it up, but from a glance it seems that the secondary intake runners and ports should be seeing more airflow than the primaries. If this is the case, it would make more sense to send more fuel into the secondaries.



Here's what we know:
Stock injector sizes are 550/850. That's a 39/61 ratio, and if Mazda sized their fuel system properly we can assume the primary/secondary airflow through the stock runners and ports was something around 40/60 also.

Your proposed sizes are 1550/1680. That's about a 48/52 ratio, which might work well if your primary runners and ports are about the same size as your secondary runners and ports. It not, you might try something smaller than 1000ccs for the additional primary injectors.

1100/1680 will keep your fuel ratio around 40/60, you could accomplish that with two sets of 550cc injectors in the primary runners.

-s-


edit: not sure I understand how your fuel injectors will be installed. If you're planning to install both the 1000cc's and the 1680cc's in the secondary intake runners (two injectors per runner?) then you'd have 550/2680, which is a 17/83 ratio. Seems like you would have a whole lot more fuel going into the secondary runner, unless the PFC lets you run a different duty cycle for the primaries and secondaries (not sure as I have a different EMS).

 

Her uns the four 1680's in series without resistors or an injector driver. He uses 850's in the primaries. No issues for the past few years.
John

 

Yea because everyone knows the cheapest guy in town is the best...

 

So is there a difinitive ultimate injector setup, with regards to having enough fuel available while being able to have a reasonable idle. Is 4 injectors in Cjs secondary rail ample for 650 whp while still maintaining a reasonable idle , using the power FC. If not , please explain.

 

I'm going to run 4 1000's in the secondary if I can ever get my hands on a CJM rail kit. :/

 

I just picked up the KG Parts secondary rail for 4 injectors from Keith this week, installing this weekend on a ground zero lower intake manifold.

Anthony

 

so if i go with 6 yaw power 1000cc injectors, would i be safe? would i just wire the secondaries in parallel and divide by half to get everything right? i am such a noob and not really sure what to buy

 

Anyone else try their primaries in the Xcessive manifold. I'm leaning in this direction for my new setup with four ID2000's.

 

I switched to e85 and changed injectors to fic (same as id) 950cc pri and 4 2150 sec., works with no issues.

 

That's a lot of fuel! What base pressure are you running? I've got limited E85 pumps in my area, so my setup will have to be flex fueled and I'd worry about drowning the engine with regular old premium at that point. Also which ECU are you using for this setup?

 

It is a lot of fuel, but I was tired of changing injectors when I changed turbos and upped the boost. I'm running 50 psi base pressure, I wouldn't worry about drowning it the new injectors have much more precise control then old style ones. Running an AEM.

 

I've been running ID1000's in the Xcessive LIM for a couple of years now. The OEM primaries are blocked off using Racing Beat 13B plugs, which fit well once they were trimmed an inch or two. The idle and throttle response aren't noticeably different than when the stock injectors were installed. This is on a stock 13B-REW, by the way.

 

Thanks, that's just the information I was looking for. I'm going to simplify my setup and remove the primary rail and lines and run 4 ID2000's in the Xcessive manifold instead.

 

Some Honda engines have a very simple fuel rail, the fuel pressure regulator bolts to a flange at the end of the fuel rail. I picked up an aftermarket Honda FPR, fabricated a simple flange and had it welded to the end of the Xcessive fuel rail... luckily the flange can be flat, since the o-ring groove is built into the pressure regulator. There are only two fuel lines in the engine bay: the feed goes into the front of the fuel rail, and the return comes straight out of the regulator on the other side of the rail.

 

Have you done this and if so, how did it turn out? Pics?

I'm waiting on my Xcessive LIM and was thinking of going this route to simply setup. 4 FIC 2150 injectors in Xcessive LIM and eliminating the Primary rail....