hey the diagram and pics on first page are not showing up

 

anybody have the color coded diagram up.. Can you please post the one MM posted is not showing. I believe I have found my everlasting problem here. It looks as if when I installed my injectors I wired the 2 middle P2 injectors wrong. To my front p1 injector I have green/white & blue/white wire connected to it and my rear p2 injector the black/blue & blue/white wire are connected to it. This is incorrect isn't it?

 

I have a thread where an owner gave me the proper colors. I will see if I can find it.

 

https://www.rx8club.com/showthread.p...light=injector

 

if I want to change some injectors... do I have to change all the 6? or try strating by the red ones and pluging the red one instead of the yellow ones...etc...

 

Unless you are boosted, you dont need larger injectors.

 

The factory ECU has the Injectors grouped. You set the CC/min and dead times for the primaries as one group and for the secondary and aux injectors as another. So as long as you change the primaries as a pair and the secondary and aux as a group you are fine.

 

I have a supercharger
I have 330whp ! but still not anought !

 

I take that is the Pettit stage II?

I have two 780cc/min low-impedance injectors if you want them. I ran them for a month with absolutely no issues but decided to go with 4 650cc/min across the second fuel rail instead of two 650s and two 780s.

I will say that the stock pcm is made to run high-impedance injectors. You would have to risk running the low-impedance injectors like I did or find something to drive them. The risk is that you might over heat the pcm. I think that risk is slight if you only run 2 out of the 6 as low, but that is only based on my experience with having no issues. If you are using a microtech unit (an int-x) to control your fuel, you will have no problem as it contains low-impedance drivers.

 

Low impedance injectors will, under most circumstances, destroy the PCM in fairly short order.
You were lucky, Carbon.

Usually, you get between 15 minutes and 5 or 6 days before the injector drivers melt.

 

Yeah. I agree. Plenty of examples of honduhs and others toasting computers; however, not a single example on an RX8 (that I am aware). I am wondering if I wasnt lucky, but that the total resistance was enough to protect the pcm.

Then again, the fact that I made it close to a month with the low impedance injectors may be only a reflection that these injectors were rarely used (in sec position iirc.)

Then again again, the second that I understood that I was running low-impedance injectors on a stock pcm I parked the car. I even pushed it into the garage.

I will admit that I want to get rid of these injectors.

I also have four yellows I dont need!

 

thanks carbone :D but i'll buy some new ones...
I read on an other thread that if I take large injectors, I have to reflash the PCM.
no big deal!
but will the OEM fuel rail accept that difference ? as the fuel pressure regulator ?

SO if I understannd right, the first injectors that can be changed are the P2...
I'll look for SARD injectors!

 

Unfortunately, I am aware of several people that ran the Int-X with low impedance injectors, sold the Int-X and promptly fried their injector drivers.

 

Just some infor about SII that is in this thread

 

Then I am incredibly lucky.

 

where cdan I buy some blue injectors ?

 

/\ used from a wrecker or new from mazda ...

 

I just order 4 of the SII Secondarys

 

hey guys...i having a lil prob wit my 8. today me n my boys went to play some football, we got to the park without any prob. i started it no prob here also, but after driving for a while i notice it was starting to lose power as i step on da gas n cuts off. could this be to a bad fuel injector?

 

/\ probably not


Moving on , I'm thinking of trying the following injector combo , any thoughts ?

P1 380 Secondary 480 P2 380

reasoning : increasing P1s will suffice for low rpm boost and having more fuel to the secondaries will even out the amount of fuel per intake tract to some extent .

 

fuel pump ?
no more fuel

 

I can't help but wonder how many people erroneously changed their injectors because they relied on some unverified published numbers rather than taking a set of unmodified OE injectors and actually having them cleaned & flow tested for an accurate baseline reference point?

 

Probably not many, since the desired flows when changing injectors are WAY beyond the maximum variation of the OE units.
I doubt anyone thought "Gee, my stockers are 293cc and I really want 314cc in that position, so lets swap them!".
Most people are going for double the OE flow or more.

 

assuming the actual numbers correlate to what's printed and the actual fuel pressure of the system

there;s not that many people running all that high of boost pressure from what I've seen

 

No. That's true.
The OE fuel system will probably suffice for most applications, though it might be on the edge.
Once you cross 300 HP, its worth the relatively minor expense to upgrade the injectors, especially in light of how thirsty the rotary is.
Cheap insurance.
And even if the published data is off by 20%, a 100% increase in capacity - even if its really 80% - is still a significant margin.
The actual flow values are a bit irrelevant as long as you know how to adjust the scaling in response to the difference between expected flow and actual AFRs.