jason len

anyone running bosch 803 injectors on megasquirt 2.2 ?

i ask because i have been told because they are low impedence i need to add a resistor to each injector if useing v 2.2 megasquirt.

anyone help

jason len

no one know

Mark V8

iTrader: (2)

You need either resistors or a flyback board so you can run PWM (pulse width modulation). I squirted my bike and to make life easier used high impedance injectors from a supercharged Jag V8 to save on aggro, flow 345cc min at 3 bar and measure around 15 Ohms on a multimeter.

Mark

Jasesapphy

iTrader: (1)

i thought ms can run high and low

jason len

so i need to solder a resistor to each injector wire? so i need 4 resistors.

also what resistors do i need to put inline on wireing loom to each injector if useing bosch 803 injectors on a v2.2 megasquirt?

anyone please advize as i dont have a clue which ones i need, and was told if i try and start it without the resistors it will either damage the injectors or burnout the ms

Mark V8

iTrader: (2)

http://www.megamanual.com/v22manual/minj.htm#wire

Mark

jason len

cheers mate,

now i need to figure below for bosch 803 green injectors

injector resistance in ohms,

hold current in amps


injector impedance in ohms

anyone know these?

ECU Monitor Enthusiast

iTrader: (1)

Surprised to learn MS cant drive low impedance injectors without alot of
fooking around and it seems it isnt sequential injection either.
Unless anyone else knows otherwise.

jason len

anyone know the figures on the above.

reality

SECS.. it's not sequential, no..

jason.. just find some high impedence injectors, save pissing about.. there are a gazzilion on ebay (search for ford racing injectors).. whats your target power?

ECU Monitor Enthusiast

iTrader: (1)

803's

Average about 2.2 ohms,

Peak current for this is 5.8 amps @ 12.8 volts A= V / R

Hold current is usually around a quarter of this which is about 1.4 amps.
(1 amp is usually used on these on weber ecu's)

To drive low impedance ijectors on a high impedance driver,
I would recomend a 10R resistor to do this on each injector.
This gives a total resistance of 12.2 ohms which will give you
a running current of about 1.0 amp.

IMO, running low impedance injectors is not the right way to go as
the reduced currents give the injector a sluggish opening time reducing
their accuracy at very light loads (idle).

jason len

SECS
thanks mate.
managed to find out its 4.7 ohms jut the last 2 now if you can work it out for me (useless at maths lol)

i opted for bosch 803 injectors as thats what most people use on a 2.1 zetec turbo engine.




reality

i paid 120 quid for a set of 4 bosch 803 injectors off a cosworth so dont really want to change now plus a bit strapped for cash.

looking for 250+ bhp.

i just trying to figure out if i need the resistors or not.

also had a nightmare day with megasquirt getting stupied controller code errors.



i managed to find

injector resistance in ohms, - 4.7 ohms

hold current in amps - ?


injector impedance in ohms - ?

reality

4.7 ohms is the impedence/resistance..

Hold current.. hmm, without testing i'd say 1 amp..

"Stupid controller errors" are usually down to a mixmatch between ecu firmware, megatune and extra code (if you're using extra)... if you follow all the instructions EXACTLY, you'll have no trouble.. ALL the information you need is there..

luke89

iTrader: (1)

jason len fineshed ur loom will try post it tomoz if i can find any money lol , any one no if st170 injecters are hi or low and also scopio 2.3 injecters?

reality

ST170 are high.. be careful with those, maybe not what you expect

Scorpio.. high.. all eec-iv injectors are high..

luke89

iTrader: (1)

thats kool both sets of my injecters are high and i have mega squirt lol

jason len

so can anyone fill these in.

bosch 803 injectors.

injector resistance in ohms =

hold current in amps =


injector impedance in ohms =

thanks

reality

Jason.. I suggest you read back in your own thread a bit as your questions have been answered twice..

jason len

yeah i know that reality mate.

but asked again as im kina mixed up

as secs said


2.2 ohms

Peak current for this is 5.8 amps

Hold current is usually around 1.4 amps

and you said


4.7 ohms

Peak current ?

Hold current 1 amp


which is diffreent vaues so was not sure thats why i asked again.

JesseT

803s work directly without any modifications or resistors.