the n326 ecu drive low-imp injectors witha resistor inline

is the n326 a peak-n-hold driver or a saturated driver using lo-imp injectors

does the n326 have enough power to drive 8 low-z injectors(of smaller cc rating)?

any other info on the n326 ecu would be helpfull!

Thanks RX200013B

 

does anybody know the answer?


bump

 

dunno about the peak n hold vs saturated

the other question is easy,

ohms law V/ I*R

v = volts, R is resistance, I = amps

if you look at mazda's resistance spec, they actually give a range. and voltage will vary a bit too so STOCK you could have this

12v/15 ohms = .8 amps

or

or 14v/12ohms = 1.2 amps

so since we're not changing voltage, and we want to keep current 1.2 or under, then you can go the other way

14v/1.0 amps = 14 ohms of resistance are needed.

http://www.gearseds.com/curriculum/i...w_triangle.gif

 

Anybody else know about the peak-n-hold or saturated question?

 

The injectors are peak and hold style but driven as saturated with the resistor packs. I don't know why you would want to hack up the stock ecu to drive more injectors when you could go with a different standalone such as a megasquirt/microtech/haltech and get much better results.

 

cause i'm building a different intake manifold and wanted to use 8- 245cc injectors instead of 4- 440cc injectors

i have a goal with the stock ecu !

 

you do know the stock na ecu runs rich with the 4x 460s. What do you expect to gain by going to 8x 245cc injectors? Also mazda spend alot of time and money developing the stock manifolds and I doubt you will be able to improve on them.

I hate to stomp on your hopes and dreams but it sounds like you want to be unique but you are going about it the wrong way.

 

the stock ecu uses saturated-style injector drivers. if you look up the part number, they can actually handle up to 3A per injector.. so if you do the math that comes out to an impedance of about 5 ohms minimum.

so if you wanted to drive 8 low-imp injectors, you would need resistors of at least 7.5 ohms on each injector. 7.5 + 2.5 = 10 ohms, 10 ohms x2 in parallel = 5 ohms, 14/5 = ~3 amps

10 ohm resistors would be a better safety margin to keep the ecu from overheating. the only problem is increased injector lag with the resistors.

high impedence injectors would work better, and they are easily found in less than 750cc sizes. no resistors would be needed in that case, and you could wire them in parallel

 

have you ever measured one? the s5's ive measured are all way fat up top, but the s4 isn't.

@ wot the richest my s4 na gets is right at 4000, it's @ 12:1, after that it leans out to about 13, and then richens up to mid 12's by redline.

the s5 is around 12:1 @4000, but just keeps getting richer, at redline it'll be low 11's high 10's

 

all i have to say is LOL!

i don't understand why people go to such extreme lengths to try and do something differently so have fun with your project.

you won't get any better results running 8 injectors versus 4. because there is only 4 intake port runners(even on a 6 port motor)...

if you think you are going to mount the injectors into the rotor housings, i hope you have $ to accomplish this because that is the only way you will notice any real performance or economy gain.

 

What do you expect to gain by going to 8x 245cc injectors?

locating the injectors in different locations, and being smaller will help with atomization,and those will be my gains!




I hate to stomp on your hopes and dreams but it sounds like you want to be unique but you are going about it the wrong way.[/QUOTE]


why don't you tell me the correct way!



quote from: gxl90rx7
the stock ecu uses saturated-style injector drivers. if you look up the part number, they can actually handle up to 3A per injector.. so if you do the math that comes out to an impedance of about 5 ohms minimum.

so if you wanted to drive 8 low-imp injectors, you would need resistors of at least 7.5 ohms on each injector. 7.5 + 2.5 = 10 ohms, 10 ohms x2 in parallel = 5 ohms, 14/5 = ~3 amps

10 ohm resistors would be a better safety margin to keep the ecu from overheating. the only problem is increased injector lag with the resistors.

high impedence injectors would work better, and they are easily found in less than 750cc sizes. no resistors would be needed in that case, and you could wire them in parallel

ok, why is the ecu sendind a saturated amps to triger P-n-P injectors, wouldn't the injectors not perform properly?


unless i dont know to use a meter, when i measure 2 injectors(of both imp, hi or low) the resistance only gets larger. i.e. 2.3 ohms x 2= 4.6 ohms, 11.8 ohms x 2=23.6 ohms, and does not mater which way they are wired.

anymore help would be great

 

Put them in a parallel circuit and resistance should get smaller.

 

i tested both, just like you would w/ speakers. positive to positive was higher, positive,neg 2 posi, neg out still got higher ohms?


the only way i know how to lower resistance is to rewire the coil itself.


that is why i'm looking for 4 ohm resistors, cause the stock resistors are 6 ohms and i want to add another 2.3 ohm coil. example 2.3+2.3=4.6+4=8.6 ohms , the stock is 2.3 +6 = 8.3 ohms.

but does the ecu have enough power to run 2 injectors off each driver?

 

just use low impedence(2.3 ohm) injectors and adjust the resistance needed by replacing the resistors in the stock resistor pack at the RF strut tower. obviously you will need to half their values and hope the ECU can take the additional load.

 

Stock drivers are saturated. Low impedence injectors are utilized because they have fewer solenoid coil windings, which allow a lower lag time (amount of "dead time" it takes for the injector to open). This is discussed in the training manual:



A 6 ohm resistor pack is used stock so that the injector coils and the driver transistors don't burn out.

 

ding ding this is why running resistors with low-imp injector causes injector lag, because these injectors are designed for a large peak current to open them (usually 4 amps). stock ecu with 6 ohm resistors is only 1.5 amp max. the difference between running high- and low-imp injectors on saturation-style drivers is usually about 10-15% fuel capacity. in other words a 720cc injector will act like a 600cc

just make sure your total injector impedance for each driver is more than about 6ohms and your ecu should be alright

 

Are all your injectors the exact same?
You should be able to get exactly half the impedance out of them by putting them in parallel if they're all the same impedance.

 

could you please tell me how to HALF the impedence?


could someone please measure the resistance of a s5 injector? thanks

 

By wiring them in a parallel circuit... I've said it three times in this thread.

4 ohms in parallel with another 4 ohms would make a 2 ohm circuit.

Should be in the FSM.

 

have you tested them yourself?



i only have a fsm for the s4.

 

Like they said above, the reistance of a series five fuel injector is in the FSM. Or 12-16ohms.

I'm not aware of (at the moment) where it is written that the DRIVERS in the ECU are peak and hold or saturated.

Seems the total resistance of the fuel injector circuit on a early series four would be 6 ohms resistor plus the 2 ohm injector for a total of 8 ohm. On a series five with no resistors it'd be closer to 13ohms for the injector resistance.

Seems the driver in the ECU is what determines what the Peak current is (along with the reistance of the injector circuit) and the hold is whatever the driver is programmed/designed for. Got me as to what the Peak current of the driver is or the Hold current is of the driver if they are Peak and Hold drivers.

AEM makes a product like this: http://www.aempower.com/ViewCategory.aspx?CategoryID=83 Actually FJO makes the product I was thinking of. Don't have the URL.

 

thanks HAILERS,

that is what i wanted to know(well still don't know), what the amps is from the driver, and if it is a saturated or p-n-p driver?

8 ohms on a saturated driver does not sound right

and how have using s5 injectors on a s4 w/o resistors worked, good, bad ?

 

sounds like a lot of work for the desired results.
if Atomization is of concern, just up the pressure and shorten PW, works great ,i already did it 10yrs ago.

my DAD used to have this sayin,,( you can sure make a simple job very complicated)

 

my dad says the same to me. he say's i'm a pro at making thing difficult.

you should have heard him when i said i want to go rotary instead of a v8!

 

I'm pretty sure they are saturated and high impedence fuel injectors without the resistor package would work although the fuel injector connector is a bit different b/t the low impedence injectors and the high. MIght have to buy a set of fuel injector connectors/pigtails and splice them to the factory harness to replace the low reistance injector connectors.

Here's a link that is somewhat related: https://www.rx7club.com/showthread.p...&highlight=FJO and there is a link in the first post on that thread that is somewhat related.