Hey guys, I think I'm going to swap my secondary injectors this weekend and want to know if I can just drop my stock secondaries in the primary location? I have a friend that is in need of some new 550's and if I can just drop my stock 850's in the pri I can let him use my 550's for his car (he broke a 550)

This would leave me with 850 pri and 1200 sec. Will I need to send my ecu off for this much change or can I just make a few changes in the PFC to correct for the larger injectors.

Oh yea, this isnt a PFC question but anyway I'm sure you guys can answer. Do you think this much injector will be ok with the stock fuel pump for a week or so? Can the pump keep up the same pressure with these larger injectors?

Thanks,
STEPHEN

 

I do not think you can use the secondary injectors on the primary port becaues the secondary injectors are much shorter than the primary injectors. If you you plug them into the primary rail, the bottom o-ring of the secondary injector will not sit properly. You will have fuel leaking through. In fact, R-Magic comes out with a primary fuel rail just for this use. I realized this while installing my upgraded secondary injectors. I was going to do the same thing and found out it will not work. So I sent my 550 cc/min to RC Enigneering and upgrade them to 950cc/min. You do not need to send out your PFC to be upgraded for this. Read your manual and you will know how to modify the injector menu on PFC.

Chuck

 

Forgot to answer your fuel pump question. As long as your fuel requirement does not change, you will not need to upgrade your fuel pump. Right after you modify the injector menu, the PFC is going to compensate for larger injectors. Let's say before you are running at 100% duty cycle, right now you should see just around 50-60%. But if you are going to increase that amount, yes, you probably will need to upgrade your pump. What kind of pump do you have anyways?

Chuck

 

Thanks man, yea I hated to post it cause i know its in the manual but I'm not going home tonight and thats where the manual is.

Anyway, I guess I'll just do the 1200 swap and leave my pri in place, I dont have time to get any from RC. I have to do this over the weekend.

I had a feeling that would be the case cause I knew they were different lengths but it seems like I've heard of people doing it.....must have been my imagination.

Thanks for the help,
STEPHEN

 

If you are just changing out the 1200cc/min injectors, all you have to do is change the value of the secondary injectors to 1200 cc/min. You do not have do anything else on that menu. About using the secondary injectors to the primary port, I do not know how those people do it. If you just plug them in, it's not going to work. You will have severe fuel leaking to the intake port cuz the bottom 0-ring has no place to sit since the injector is shorter. Maybe that's one of the reason their cars are not idling properly?? If you can do that, why would R-Magic come out with a primary fuel rail to use the seondary injectors? Maybe Japanese people are not as smart as we are? I really doubt that.

Chuck

 

Interesting,

A rather long previous thread in this forum (since deleted I think)came to the conclusion that the injector size setting was only used when the PFC calculates the staging of the primaries and secondaries and that the fuel correction map needed to be altered to reap the benefits of larger injectors. Have you actually seen first-hand injector duty cycle drop in response ONLY to changing the injector size? Great to know this if so.

Alan Cross

 

right now I am using 950 cc/min primary injector and 1300 cc/min secondary injectors. Before I do the swap, my injector duty cycle was at 95% at 13 psi. Right now it's at 60%. I did not do anything ot the fuel correction map. All I did is change the values for the injector sizes under the injector menu. That's just my personal experience.

Chuck