Jump to content
SAU Community

Power For Rb25Det


Nic19
 Share

Recommended Posts

Hey guys just rewiring a track only car so it's all new loom being made. I am wondering if I need to relay the ecu power? My mate keeps telling me I do but thought I would check. Is it relayed in the r33???

Link to comment
Share on other sites

You should run relays for ECU, fuel pump, injectors and coil packs. Don't forget the CAS and Idle control both need a 12V feed so some of the ECU manufacturers fail in their instructions. Then just your normal sensor 5v to the others (TPS and Coolant temp etc)

If it's a track car, make sure you avoid using solder as the vibrations from a high revving track car can cause wiring problems later in life. Pretty much every plug on your engine can be sourced from Superior Connection. Re pin everything for a completely bulletproof loom

Link to comment
Share on other sites

Well it's mainly the body loom I'm re doing. Motor loom is gonna be the stock r33 loom just neatened up. Does the stock loom already have the relays built in for injectors and coilpacks? And it will have the 12v feed for CAS and idle control already I think.

Also with relaying the ecu, do I need one for both constant and ign?

Link to comment
Share on other sites

Well it's mainly the body loom I'm re doing. Motor loom is gonna be the stock r33 loom just neatened up. Does the stock loom already have the relays built in for injectors and coilpacks? And it will have the 12v feed for CAS and idle control already I think.

Also with relaying the ecu, do I need one for both constant and ign?

Yes you will need constant & ignition trigger, fuel pump trigger. If you have a look at my link below you will see what you need. Rb25, Rb20 looms are pretty similar NOT identical

Link to comment
Share on other sites

Well it's mainly the body loom I'm re doing. Motor loom is gonna be the stock r33 loom just neatened up. Does the stock loom already have the relays built in for injectors and coilpacks? And it will have the 12v feed for CAS and idle control already I think.

Also with relaying the ecu, do I need one for both constant and ign?

If you are using the factory loom it should already have those relays. The only additional ones you should ever need is injectors and coil packs. It's not mandatory but the more constant voltage you can get to critical engine components, the better.

Link to comment
Share on other sites

If you are using the factory loom it should already have those relays. The only additional ones you should ever need is injectors and coil packs. It's not mandatory but the more constant voltage you can get to critical engine components, the better.

If the loom is rated to the required current draw there should be no need for these, if there is a voltage drop it suggests the loom is damaged or old and a relay is just a bandaid fix anyway, however most people are using old stock looms so there is probably a benefit in using them here.

If you are wiring it all up from scratch just use the correct guage wire and don't bother though.

Link to comment
Share on other sites

Based on what he said in his previous post:

"Well it's mainly the body loom I'm re doing. Motor loom is gonna be the stock r33 loom just neatened up."

Having dedicated relays for spark and injection isn't a bandaid fix for anything. It can be a bandaid fix, but there is certainly ways to improve Nissan's design. Dedicated power is a very good idea if you are chasing reliable horsepower and even more so when you have a track car

Link to comment
Share on other sites

What I was getting at is the standard loom should provide dedicated reliable power to those things at all times, if it doesn't then it means the wiring is faulty, they wouldn't have designed a loom that doesn't power ignition properly under all circumstance, hence adding a relay doesn't improve the situation, unless of course the loom is faulty in which case I think it is a bandaid solution and the loom should be fixed.

Edited by Rolls
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share



  • Similar Content

  • Latest Posts

    • Got some decent progress after work yesterday and also today. Got the ECU all wired and passenger side interior all back together. Kept the wiring up nice and high to avoid people standing on it. Got the surge tank relays rewired and tidied up the pump wiring and cut a hole to bring the cables through.  I found a spare USB cable I had lying around so I decided to cut it up and see if I could use it for my CAN 1 bus. Turned out one of the pins I needed was to the shield of the cable so i cut it up and desoldered it and resoldered to the correct pins.  Had the issue with the powersteering hose hitting the A/C compressor and fan shroud. I pulled the bracket off and modified it to remove the front mounting point which now clears it all. Will keep an eye on it to see if theres any signs of fouling once it's up and running.
    • That's some good input mate. Nice.
    • So today I went well outside my comfort zone (again) to replace my valve cover gasket.  I have had a big leak over the exhaust leading to a lot of smoke and smell every time I drove it. The leak was in the rear driver's corner.  The job wasn't hard as such, just a bit finicky and time consuming.  The old gasket was rock hard and broken right where the leak was.  The leaky corner had so much sitting oil in it.  The good news to my amateur eyes was no buildup or sludge under the cover. It all looked fairly nice in there.   I haven't started it yet. I ran out of light and body when putting the coils and injector loom back in. Probs only 30min left for the morning.  I was so nervous putting the cover back on, I must have lifted it 5 times to make sure the gasket was still seated properly. God it's going to be nice to be leak free and not make other traffic light queuers think my car is about to explode.
    • Gave the Mazda it's first wash, it will need some clay, a light compound, and polish polish to remove a few swirl marks, but that will be a job for when I have a full day to get my DA polisher action on
    • Just did this job on my 32 with the boost doc kit. was quite simple to fit, hardest part was getting the rubber bungs back on the firewall. does anyone know how the heater will work now without the flap in the bend? Will I just have a heater on 24/7 now?
×
×
  • Create New...