mono4lamar

iTrader: (32)

I'm debating eliminating my primary rail and running a 4 port rail on the Xcessive LIM. I know having a fuel injector as close to the combustion chamber is the best way to go but in spite of simplification I'm debating this conversion. Having three lines in the engine bay would be nice. One feed, one cross to the FPR, and one return line sounds nice! I'm guessing that the injector timing would have to be advanced SLIGHTLY as it's further away from the chamber.

I'm asking for someone with experience or someone that can obviously have some educated say in the matter. I would like to keep the "thinkers" out of this one. I'll think of more things to say later. As for now lets get the replies!

S3DF

I'm currenty getting it back together. I opted to place six injectors but running only 4 since I dont have a way to control the additional two. If you have an aftermarket fuel rail send it to Rich from Xcessive to bore the additional holes, place two injectors as block off insted of completely making the manifold hole useless, this will alow you for future mods if there are any plans. If you dont have an aftermarket fuel rail buy the Xcessive rail for convenience. CJ-Motorsports is revising their fuel system to work with the Xcessive LIM.

If you are running low impedance injectors its recommended to use resistor box like FJO injector drivers because separate resistors will slow down the circuit, an economical way to do this is sourcing out from Honda, Nissan or NA RX7 which uses low impedance injectors.

AMRX7

I ran the 4 injectors only in the Xcessive manifold for a couple years. I had 4x1000cc which may not have been the best way to go. Probably the biggest issue with this setup was drivability/idle issues. It was difficult to get a clean low (<1200rpm) idle with the relatively big primaries so far upstream. It also was also difficult to get rid of an off idle stumble when touching the throttle.

I ended up moving the primaries back to the stock location and this seemed to help with some of the drivability issues. I think having the injectors so close to the port helps when you have a large injector and not much airspeed. It was also interesting that when I moved the injectors back the car ran alot richer and ultimately needed about 10% taken out of the map.

The plumbing for the 4 injectors on one rail was nice, though. Very simple and clean.

-Andy

Zero R

iTrader: (1)

I would not recommend it unless you have to do it, for car driven on the street it is a pain to get the car to run smoothly.

mono4lamar

iTrader: (32)

I wouldn't send a rail to Xcessive. I know Keith from KG Parts quite well and I'm sure he'll take care of this. I have the FJO injector driver module . I'm nobody's fool I know how injector location is key. But simplicity is a godsend...

ryan1

iTrader: (5)

Keith currently has my Xcessive manifold, so he will offer a 4 port rail shortly.

mono4lamar

iTrader: (32)

^ You're going to run a 4 port setup Ryan?

ryan1

iTrader: (5)

Ya, stock 550 in the stock pri. rail. Then 1680 and 1000 in the secondary rail.

S3DF

What kind of engine mangement your using?

S3DF

I wouldn't send the rail to Keith. I send mine to Rich because Keith was going to charge more.

ryan1

iTrader: (5)

pfc, with an fjo injector driver

mono4lamar

iTrader: (32)

Not a chance. Keith is an upstanding individual... Xcessive rails are ridiculously expensive.

- Ryan, what are you using to control your 1000cc injectors?

GoodfellaFD3S

iTrader: (213)

Keith is the man.

I have enough inj for 600 rwhp, I'm happy with four.

ryan1

iTrader: (5)

fjo injector driver

S3DF

Lets clear this, I have KG rails modified by Xcessive.

S3DF

So is that a total of six injectors being run by a Power FC?

mono4lamar

iTrader: (32)

I have the FJO injector driver also. It does not "control" injectors. It's a Peak and Hold module...

ryan1

iTrader: (5)

Stock 550cc pri. driven directly by the pfc. 1680s and 1000s are driven by the fjo box, controlled by the pfc.

S3DF

I'm skeptical because I have never heard anybody use the power FC to run the injectors in batch specially two injector size in the secondary. If your using the same pulsed width for both 1680 and 1000 they will run different duty cycles. Let us know how it turn out.

ryan1

iTrader: (5)

Even though they are different flow rates, won't they still run the same duty cycle?
Since duty cycle is on vs off time, wouldn't 50% be 50% on both injectors? If this is not the case,then I guess I need to run 4 equal sized secondarys. I was wanting to run the 1000/1680, because I don't need 4 1680s. I was concerned that 4 1680s coming online would cause a rich spot that couldn't be tuned out, similiar to 850s in the primary.

rxrotary2_7

Maybe I am missing something here... did I ever quote you a price to modify the rail? I dont recall that because the first person to ask was Ryan1. I am sure he is happy with the price.


To answer Lance, I wouldn't do away with the primary unless you had to. idle and throttle response is going to suffer. give me a call if you need to.

pp13bnos

iTrader: (1)

I know that Ralph at GZ runs 4 1680s, and 850 primarys off of the pfc. From what he said, the injector drivers would be the first thing to go in the power fc. How he does it, I don't know. CJ

mono4lamar

iTrader: (32)

I tried Keith, you're a very busy man! I'm going to keep the primary and secondary rail. I was just looking to get a concrete answer. I read many threads that had no comment to the drive-ability or tuning problems. I might try giving you a shout tomorrow in the afternoon. I might have some more goodies to have you machine... God help you if I ever get your cell number!

ryan1

iTrader: (5)

I e-mailed FJO and they confirmed it will work as I thought:

If I understand correctly, one EMS channel will drive 2 injector driver
channels? The paired channels will be a 1000 and a 1680? If this is correct,
what will happen is that each injector will open and close at the same time
[ignoring very slight differences in opening/closing response of the 2
injectors]. The difference will be that the 1000 will flow less than the
1680. What you have effectively created is a 2680cc super injector for each
rotor and the duty cycle of the injector will be what ever the EMS's duty
cycle is. Idle adjustment may be a bit of a problem with that fuel flow.

S3DF

[QUOTE=rxrotary2_7;8146792]Maybe I am missing something here... did I ever quote you a price to modify the rail? I dont recall that because the first person to ask was Ryan1. I am sure he is happy with the price.


You responded to my work email a while back. I ask Xecessive and You for independed quote at the same time Xecessive was $10 cheaper.