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Why 4 fuel injectors vs 6 on the '09's?

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Old 01-12-2009, 09:29 AM
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Originally Posted by heyarnold69
umm .... I don't have that issue
Nor do I; but then I make a point of exercising the auxiliary injectors several times a day along with the auxiliary throttles. This isn't my first six port rotary.
Old 01-12-2009, 01:10 PM
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with 4 injectors they were able to decrease fuel pressures. Maybe they saw something. Heck in 60K i am on my 4th fuel pump.
OD
Old 01-12-2009, 01:34 PM
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Decrease fuel pressure? What did I miss? Where was that mentioned? What did it change to?
Old 01-12-2009, 08:32 PM
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speculating----relax RG
Does seem logical ?
OD
Old 01-13-2009, 11:54 AM
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A lot of people are assuming that the 6 injector setup would have been inherently superior somehow, and they are wondering how much of a downgrade 4 injectors could be. I think the bigger question is--what the heck was the point of the 6 injectors in the first place, considering that setup had two primary injectors? That's the bigger question to me. The fuel flow from the 6 injector setup versus the new 4 injector setup is really close. 6 injectors just seems retarded.
Old 01-14-2009, 06:52 AM
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Why did the old 4 port 13B's only have 2 injectors each flowing 680cc and then they changed the newer 6 port 13B to have 4 injectors each flowing 460cc??
Old 01-14-2009, 08:07 AM
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Originally Posted by rxrotary2_7
Why did the old 4 port 13B's only have 2 injectors each flowing 680cc and then they changed the newer 6 port 13B to have 4 injectors each flowing 460cc??
I was under the impression that the first fuel injected 13B was in the RX-7 GSL-SE and the addition of 2 more injectors for the FC was to allow improved atomisation of fuel (at least that's my recollection).

Is it possible, therefore, returning to the original subject that the new injectors used in the 2009 achieve atomisation that is as good as with the 6 injector setup; but without the issues (complexity and reliability) of the 6 injector setup?
Old 01-14-2009, 08:11 AM
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Technology has progressed pretty far ... however is there anything out there stating that this is in fact the case.
Old 01-14-2009, 08:40 AM
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Originally Posted by rxrotary2_7
Why did the old 4 port 13B's only have 2 injectors each flowing 680cc and then they changed the newer 6 port 13B to have 4 injectors each flowing 460cc??
Actually it was a 6 port 13B in the GSL-SE that had 2 injectors. The engine only made 138 hp. 2 was plenty.
Old 01-14-2009, 11:37 AM
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Originally Posted by rotarygod
Actually it was a 6 port 13B in the GSL-SE that had 2 injectors. The engine only made 138 hp. 2 was plenty.
youre right about the 6 port in the 5letter, forgot that as it has been so long
Old 01-15-2009, 02:14 PM
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Nope. Same pump. Same pressures.

https://www.rx8club.com/showthread.p...09#post2817709

S2 pump has changed..
Old 05-24-2009, 01:24 PM
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It seems to me that 80% of the engine changes are lubrication \reliability based.
In keeping with that, wouldn't the engine recieve better lubrication by 4 injectors shooting 2040 CC all the time, over 6 Injectors shooting 1600 most of the time and 2100 under certain circumstances?
Old 05-27-2009, 11:14 AM
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The 09 injectors are in fact superior in terms of atomization. That's as much as I can provide technically. They are excellent injectors.

Paul.
Old 05-27-2009, 09:23 PM
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Originally Posted by Mazmart
The 09 injectors are in fact superior in terms of atomization. That's as much as I can provide technically. They are excellent injectors.

Paul.
Forgive me if this is an obviously bad idea; but since they are superior in atomization, would it be advantageous to retro-fit them on a 2004-2008?
Old 05-27-2009, 09:59 PM
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/\ Not an expert here, but I think trying to convert a S1 fuel and intake to the latest S2 (09) would not be worth the trouble or cost involved...

I see issues with the S1 PCM (ECU) which also would need to be changed as it has different fuel maps.
Then you have other non related PCM compatibility issues with other tasks the PCM does, two EMOP's, new oil pressure sensors, etc, all calibrated for a totally different MOP set up.

Intake fuel runners would need changing, unless you can put in two blind block off bolts in the runner...I see at lot of headaches...

Paul, what do you think??
Old 05-28-2009, 12:42 AM
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it has been done.

but in a fi car..

the sizes dont match up for a 04 to 08 car..

beers


Originally Posted by longpath
Forgive me if this is an obviously bad idea; but since they are superior in atomization, would it be advantageous to retro-fit them on a 2004-2008?
Old 05-28-2009, 12:44 AM
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Originally Posted by Symbioticgenius
It seems to me that 80% of the engine changes are lubrication \reliability based.
In keeping with that, wouldn't the engine recieve better lubrication by 4 injectors shooting 2040 CC all the time, over 6 Injectors shooting 1600 most of the time and 2100 under certain circumstances?
the fuel injectors have nothing to do with lubrication..

beers
Old 05-28-2009, 12:51 AM
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Originally Posted by swoope
it has been done.

but in a fi car..

the sizes dont match up for a 04 to 08 car..

beers
placing the 09 fuel injectors in a 04 to 08 car been done sucessfully in a fi car?

i am planning on going the same route
Old 05-28-2009, 01:08 AM
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Originally Posted by gregs
placing the 09 fuel injectors in a 04 to 08 car been done sucessfully in a fi car?

i am planning on going the same route
yes.

beers
Old 08-24-2009, 02:23 PM
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Originally Posted by longpath
Is it possible that the switch to 4 injectors was intended as a reliability improvement by ensuring that all the injectors see duty cycles on a regular basis, unlike the 6 injector setup where the auxiliary might not see use if someone was new to the rotary and neglected to bring the revs above 6500?
Sorry to dig up an old thread, but this more than any other answer works for me. For those who don't exercise the engine above 6250rpm on a regular basis (or even at all!) then the injectors get clogged. Mazda have to think of the more casual car buyer that doesn't go all technical under the hood

Ian.
Old 08-24-2009, 05:20 PM
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Originally Posted by HypoThermia
Sorry to dig up an old thread, but this more than any other answer works for me. For those who don't exercise the engine above 6250rpm on a regular basis (or even at all!) then the injectors get clogged. Mazda have to think of the more casual car buyer that doesn't go all technical under the hood

Ian.
I'm unsure how you could operate this vehicle without going above 6250 on somewhat of a regular basis.
Old 08-25-2009, 03:42 PM
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Originally Posted by Flashwing
I'm unsure how you could operate this vehicle without going above 6250 on somewhat of a regular basis.
Which is kind of what I'm getting at. Hard as it might be to believe, many people approach this car and drive it in the same way that they did their last one: change up at 4k, cruise one or two gears higher than they need to, revving to the limiter is just not the done thing.

I've seen the effect that a sticky third port has on a car, and often this is the reason for going to a forum is to understand what that behaviour is all about. Only then do many join up with forums and learn about what those of us here know. Mazda still has to think of those people...

Anyway, that's my 'tuppence worth - thanks for reading.

Ian.
Old 08-25-2009, 08:27 PM
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the 09 f inj rock.
the 09 injector were placed on an earlier model fuel rail where the yellows sit.
OD
Old 05-26-2011, 11:00 AM
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Originally Posted by Easy_E1
I haven't found any specific CC size on these yet. Did get part numbers for the primary and Secondary injectors.

Primary N3R213250
Secondary N3R113250
According to the parts diagram I got from my local mazda parts department, those part numbers are switched. Should be

Primary (located in houseing) N3R113250
Secondary (located in LIM) N3R213250
Old 06-05-2011, 02:44 PM
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Are they plug and play on an 04-08? and yeah i know, this must have been thread revival week lol


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