SR20 swap guide?

Started by Dr.Steels · Apr 6, 2012 · 3postsSMF 2010–26

Dr.SteelsApr 6, 2012, 10:06 pm · #1

Just picked up an 85 200sx fastback today, its a no-runner (likely a fuel pump issue, not diagnosed yet). Im going to get it running but I want to swap in an SR20 down the road, starting my research now.

Is there a Swap guide available
What parts do I need?
What wiring needs to be done?

Post Merge: 02:45:57 AM / 07-Apr-12

So Thus far search has brought me to the following conclussions:
1. Use the CA18e transmition that is already in my car
2. Use the SR bellhousing and starter
3. If i do as listed above the stock motor mounts will be sufficient and will not need modification.
4. This allows me to use the stock drive shaft and not have to cut a hole for the shifter. :shifty:

Time to go compare a s12 KA 24e swap thread to a sr20 swap thread for s13 for the wiring conclusions.

ArroApr 10, 2012, 6:10 pm · #2

Read a lot on here... the KA swap info is nearly identical to what you need to do with an SR, and that should be helpful.

Dr.SteelsApr 19, 2012, 12:31 pm · #3

s12 to s13 KA24e wiring info for MKi
posted image
s13 ka24de to sr20det

SR Wire Color KA Wire Color Function
Black Black Ground
Blue / Green Stripe Blue / Green Stripe AC Signal
Blue / Black Stripe Blue / Black Stripe Water Temperature Signal
Orange Orange Ignition Start
Yellow / Red Stripe Yellow / Red Stripe Tachometer Signal
Yellow / Green Stripe Yellow / Green Stripe Speedometer Signal

These sr20det wire are from the "white plug" near the ECU.

Black / Pink stripe Black / Pink stripe Fuel pump relay
Green / Orange stripe Green / Orange stripe Transmission neutral switch
Red / Black stripe Red / Black stripe ECU relay
Green / Yellow stripe Green / Yellow stripe* AC relay
Black / White stripe Black / White stripe ECU power
Blue / Green stripe Blue / Green stripe AC relay
Black / Yellow stripe Black / Yellow stripe Idle air control solenoid power
Brown Any +12V Switched** O2 sensor power
Red Red ECU backup power
Black / Red Black / Red stripe Main ignition power

To "run" the KA24de on a MI all you need is

Power to ECU constant
Power to ECU ignition
Ground
Starter signal

However because I want a fully functioning guage cluster I should also connect the
yellow/red to blue/white for tacho signal
Blue/black to purple/white for CTS gauge in cluster

NOTE: Stock tacho probably won't work; I know that with CA18det's a wire can be used to combine the four signal wires to the COP post-igniter, with a diode near signal wire to prevent incorrect firing. Would this work for the sr20DET as well?

Post Merge: 12:34:23 PM / 19-Apr-12

Two useful links
one
two

SR Wire Color	KA Wire Color	Function
Black	Black	Ground
Blue / Green Stripe	Blue / Green Stripe	AC Signal
Blue / Black Stripe	Blue / Black Stripe	Water Temperature Signal
Orange	Orange	Ignition Start
Yellow / Red Stripe	Yellow / Red Stripe	Tachometer Signal
Yellow / Green Stripe	Yellow / Green Stripe	Speedometer Signal

Black / Pink stripe	Black / Pink stripe	Fuel pump relay
Green / Orange stripe	Green / Orange stripe	Transmission neutral switch
Red / Black stripe	Red / Black stripe	ECU relay
Green / Yellow stripe	Green / Yellow stripe*	AC relay
Black / White stripe	Black / White stripe	ECU power
Blue / Green stripe	Blue / Green stripe	AC relay
Black / Yellow stripe	Black / Yellow stripe	Idle air control solenoid power
Brown	Any +12V Switched**	O2 sensor power
Red	Red	ECU backup power
Black / Red	Black / Red stripe	Main ignition power