Notices
Series I Tech Garage The place to discuss anything technical about the RX-8 that doesn't fit into any of the categories below.

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

Old Jan 12, 2009 | 09:29 AM
  #76  
longpath's Avatar
Registered
iTrader: (1)
 
Joined: Apr 2005
Posts: 631
Likes: 3
From: Stamford, CT
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.
Reply
Old Jan 12, 2009 | 01:10 PM
  #77  
olddragger's Avatar
Registered
iTrader: (3)
 
Joined: Apr 2004
Posts: 10,828
Likes: 40
From: macon, georgia
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
Reply
Old Jan 12, 2009 | 01:34 PM
  #78  
rotarygod's Avatar
Thread Starter
Registered
 
Joined: Apr 2003
Posts: 9,134
Likes: 26
From: Houston
Decrease fuel pressure? What did I miss? Where was that mentioned? What did it change to?
Reply
Old Jan 12, 2009 | 08:32 PM
  #79  
olddragger's Avatar
Registered
iTrader: (3)
 
Joined: Apr 2004
Posts: 10,828
Likes: 40
From: macon, georgia
speculating----relax RG
Does seem logical ?
OD
Reply
Old Jan 13, 2009 | 11:54 AM
  #80  
arghx7's Avatar
Registered
 
Joined: Apr 2005
Posts: 654
Likes: 4
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.
Reply
Old Jan 14, 2009 | 06:52 AM
  #81  
rxrotary2_7's Avatar
Registered User
 
Joined: Aug 2003
Posts: 24
Likes: 0
From: south Jersey
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??
Reply
Old Jan 14, 2009 | 08:07 AM
  #82  
longpath's Avatar
Registered
iTrader: (1)
 
Joined: Apr 2005
Posts: 631
Likes: 3
From: Stamford, CT
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?
Reply
Old Jan 14, 2009 | 08:11 AM
  #83  
heyarnold69's Avatar
Rotary wanabee
iTrader: (1)
 
Joined: Jul 2007
Posts: 1,978
Likes: 0
From: Long Island, NY
Technology has progressed pretty far ... however is there anything out there stating that this is in fact the case.
Reply
Old Jan 14, 2009 | 08:40 AM
  #84  
rotarygod's Avatar
Thread Starter
Registered
 
Joined: Apr 2003
Posts: 9,134
Likes: 26
From: Houston
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.
Reply
Old Jan 14, 2009 | 11:37 AM
  #85  
rxrotary2_7's Avatar
Registered User
 
Joined: Aug 2003
Posts: 24
Likes: 0
From: south Jersey
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
Reply
Old Jan 15, 2009 | 02:14 PM
  #86  
ASH8's Avatar
Super Moderator
 
Joined: Apr 2005
Posts: 10,880
Likes: 340
From: Australia
Nope. Same pump. Same pressures.

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

S2 pump has changed..
Reply
Old May 24, 2009 | 01:24 PM
  #87  
Symbioticgenius's Avatar
You Dumbass!!!
 
Joined: Feb 2008
Posts: 719
Likes: 0
From: New York
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?
Reply
Old May 27, 2009 | 11:14 AM
  #88  
Mazmart's Avatar
Registered
iTrader: (12)
 
Joined: Mar 2004
Posts: 4,794
Likes: 67
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.
Reply
Old May 27, 2009 | 09:23 PM
  #89  
longpath's Avatar
Registered
iTrader: (1)
 
Joined: Apr 2005
Posts: 631
Likes: 3
From: Stamford, CT
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?
Reply
Old May 27, 2009 | 09:59 PM
  #90  
ASH8's Avatar
Super Moderator
 
Joined: Apr 2005
Posts: 10,880
Likes: 340
From: Australia
/\ 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??
Reply
Old May 28, 2009 | 12:42 AM
  #91  
swoope's Avatar
Zoom-Freakin'-Zoom
iTrader: (5)
 
Joined: Jan 2004
Posts: 14,603
Likes: 36
From: orlando, fl
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?
Reply
Old May 28, 2009 | 12:44 AM
  #92  
swoope's Avatar
Zoom-Freakin'-Zoom
iTrader: (5)
 
Joined: Jan 2004
Posts: 14,603
Likes: 36
From: orlando, fl
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
Reply
Old May 28, 2009 | 12:51 AM
  #93  
gregs's Avatar
Pull My Finger
iTrader: (7)
 
Joined: Jul 2007
Posts: 1,786
Likes: 19
From: So.Cal
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
Reply
Old May 28, 2009 | 01:08 AM
  #94  
swoope's Avatar
Zoom-Freakin'-Zoom
iTrader: (5)
 
Joined: Jan 2004
Posts: 14,603
Likes: 36
From: orlando, fl
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
Reply
Old Aug 24, 2009 | 02:23 PM
  #95  
HypoThermia's Avatar
Registered User
 
Joined: Jun 2004
Posts: 3
Likes: 0
From: London
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.
Reply
Old Aug 24, 2009 | 05:20 PM
  #96  
Flashwing's Avatar
3-wheeler
 
Joined: Dec 2005
Posts: 2,734
Likes: 1
From: Phoenix
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.
Reply
Old Aug 25, 2009 | 03:42 PM
  #97  
HypoThermia's Avatar
Registered User
 
Joined: Jun 2004
Posts: 3
Likes: 0
From: London
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.
Reply
Old Aug 25, 2009 | 08:27 PM
  #98  
olddragger's Avatar
Registered
iTrader: (3)
 
Joined: Apr 2004
Posts: 10,828
Likes: 40
From: macon, georgia
the 09 f inj rock.
the 09 injector were placed on an earlier model fuel rail where the yellows sit.
OD
Reply
Old May 26, 2011 | 11:00 AM
  #99  
Highway8's Avatar
Registered RX8 Nut
iTrader: (11)
 
Joined: Jul 2007
Posts: 1,366
Likes: 9
From: Fairfield, CA
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
Reply
Old Jun 5, 2011 | 02:44 PM
  #100  
ManyRX's Avatar
SiNoEsRotorNoEsMotor
iTrader: (5)
 
Joined: Dec 2006
Posts: 186
Likes: 0
From: Philly! ! !
Are they plug and play on an 04-08? and yeah i know, this must have been thread revival week lol
Reply

Thread Tools
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -5. The time now is 09:22 AM.