Injectors again -still confused
04-23-2005, 06:57 PM
#16
Race Director
"This does answer another question I had forming - why not stick a 3ohm resistor and halve the current again? - cos the injectors wont get enough current to drive them."
Exactly. Peak & hold injectors need about 2 amps to fire. No resistors send 5 amps through them, more than necessary. Simple 1.0-1.5 ohm paired resistors will lower this to 3-3.5 amps, still more than enough. Upping the resistors to 3.0 ohms will reduce current to 1-2 amps, which is below spec. You can use 3.0 ohm resistors per injector. Check out page-38. in the MoTeC catalog (zipped-PDF), they've got one that can be used individally. Impedance-matching is lost art with the advent of digital electronics.
Exactly. Peak & hold injectors need about 2 amps to fire. No resistors send 5 amps through them, more than necessary. Simple 1.0-1.5 ohm paired resistors will lower this to 3-3.5 amps, still more than enough. Upping the resistors to 3.0 ohms will reduce current to 1-2 amps, which is below spec. You can use 3.0 ohm resistors per injector. Check out page-38. in the MoTeC catalog (zipped-PDF), they've got one that can be used individally. Impedance-matching is lost art with the advent of digital electronics.
04-23-2005, 06:58 PM
#17
Race Director
"This does answer another question I had forming - why not stick a 3ohm resistor and halve the current again? - cos the injectors wont get enough current to drive them."
Exactly. Peak & hold injectors need about 2 amps to fire. Using no resistors send 5 amps through them, much more than necessary. Simple 1.0-1.5 ohm paired resistors will lower this to 2.5-3.0 amps, more than enough. Upping the resistors to 3.0 ohms will reduce current to 1-2 amps, which is below spec. You can use 3.0 ohm resistors per injector. Check out page-38. in the MoTeC catalog (zipped-PDF), they've got one that can be used individally. Impedance-matching is lost art with the advent of digital electronics.
Exactly. Peak & hold injectors need about 2 amps to fire. Using no resistors send 5 amps through them, much more than necessary. Simple 1.0-1.5 ohm paired resistors will lower this to 2.5-3.0 amps, more than enough. Upping the resistors to 3.0 ohms will reduce current to 1-2 amps, which is below spec. You can use 3.0 ohm resistors per injector. Check out page-38. in the MoTeC catalog (zipped-PDF), they've got one that can be used individally. Impedance-matching is lost art with the advent of digital electronics.
05-05-2005, 04:30 PM
#18
Burning Brakes
Thread Starter
Whilst checking the wiring diagrams before indstalling my resistors (14 and 15, spot on Waterguy! thanks) I spotted the S(2?) has a resistor pack for the fuel injectors - anyone know anything about it?
Vol 5 (P155 of 262 on my PDF or 97-212 I think)
Tony
Vol 5 (P155 of 262 on my PDF or 97-212 I think)
Tony
