edgars95rx7

iTrader: (5)

I found this site but im not sure what resistor to purchase.
NTE RESISTOR 25 Watt - Wholesale Electronics

ill be running 2 1600cc injectors for now

or if you cold guide me to the right place to buy them it would be much appreciated.

Mahjik

iTrader: (1)

Rotary Performance | FD Fuel System
Injector Resistor

edgars95rx7

iTrader: (5)

so I did the math just like damian's kgs part write up.
stocks read 14.1 all around`
New bosch 1680 have a reading of 4.8

then we do the math

12v/14.1=.851 amps stock injector

12v/4.8=2.5 amps bosch 1680cc


I could go with a 8ohm or 10ohm. then is depends whether I should get 10w or 25w. 1% or 5% tolerance


with a 8ohm resistor
12v/12.8=.94 amps

with a 10ohm resistor
12v/14.8=.81amps

So any recommendations guys?

j9fd3s

iTrader: (3)

i think either is fine. i'd probably do the 10A just because its a rounder number

Speed of light

iTrader: (8)

Like j9 said either will work; however, I would choose the 8 ohm as you'll get better injector response (resistors increase lag times dramatically, so the smaller the better). If the resistor is gonna be in a relatively cool location, the 10w is okay; if you're putting them near the injector and over the engine, you might want to use the 25 watt (as the resistor is derated somewhat if preheated). Your dissipation is going to be something less than 10w at max duty cycle. Resistors are generally rated for continuous duty at a specified temperature and you can generally exceed the max rating for short periods of time without consequence. Tolerance is not critical in this application so 5% is more than adequate.

Hope this helps.

edgars95rx7

iTrader: (5)

hi I saw on a post that the blue connector on ecu has the 12v+ for the injectors. can I install a single resistor on that wire rather than installing 4 separate resistors?
quote:


FD3S X-05 PLUG - BLUE ECU PLUG (93 S6 JDM)

WL BG XX XX Y BrB BL
X BrW BY BrY BW R Br

WL - Cooling fan relays
BG - EGR
Y - 1st Gear
BrB - TPS ground
BL - EGR
BrW - Pressure sensor
BY - +12 Injectors
BrY - Fuel temperature sensor
BW - +12 to solenoids
R - 2nd gear switch
Br - Neutral switch

ondabirdhouse

iTrader: (26)

Simple answer...No.
The injectors are operated by grounding them via the ecu...they always see 12v when the ignition is switched on. To fire an injector the the ecu grounds them for a brief moment (milliseconds).

scotty305

iTrader: (2)

I agree, running a single resistor will not do the job correctly. It shouldn't be a problem to add the four resistors to the signal wires near the ECU (as opposed to adding the resistors in the engine bay near the injectors).

Adding resistors to low-impedance injectors is not a good idea, especially when working with a rotary. The resistor slows down the injector opening time, decreases the maximum available fuel delivery at high duty cycle / high RPM. In addition, most low-impedance injectors are old designs with weird flow characteristics near idle... and rotaries aren't the happiest engines at idle in the first place. The only real advantage to low-impedance injectors is you can get used ones for cheap, because there are a lot of people switching to modern high-impedance injectors.

If you haven't already hacked up your harness, I'd recommend choosing modern injector designs that will flow more fuel without requiring you to add resistors. Many people are happy with Injector Dynamics ID725, ID1000, ID2000 injectors, available at Fuel System | Full Function Engineering . I've been running ID1000's since 2009, they have worked well. I've heard good things about Fuel Injector Clinic high-impedance injectors as well.