Discussion and questions related to the course EFI Wiring Fundamentals
So I have done lots of wiring before but never an ECU. I have pretty much failed at the first hurdle when it has come to wiring the Xtreme ECU to my car. I need some help/pointers/direction on quite a few bits as what i thought wasn't going to be to a fairly simple task, has me at a complete loss right now!
Before i give up and spend a fortune on getting someone to do it for me, can anyone help?
So I have an RX7 with an LS3 and twin turbos. I know the engine has the 24x reluctor wheel and the 2006-2007 LS2 GTO Harness.
So there is quite a few things i am confused about which i are all in the attached spreadsheet. If someone could have a look at it and give some feedback that would be greatly appreciated.
Also, there are a lot of grounds on the Link Plugs. Where do i wire these too? Also the shielded ground?
We'll do everything we can to help out and get your wiring sorted without you needing to spend a fortune. Going to need some more details on the car though, because it sounds epic!
For your grounding question, the four black ground wires on the Xtreme headers are power grounds, so they get connected to a good solid grounding point on the engine.
The 'Ground Out' wire is the sensor reference ground, so its get wired to the majority of your sensors.
The Shield/Ground pins are where the shielding braid of the trigger / knock wiring gets connected to.
I've had a quick look at your spreadsheet, and will be able to help. I'll have to get a bit more in depth and see what I can track down regarding the OEM wiring harness design. I'll get googling over dinner tonight and report back :-).
Thanks very much, I appreciate your time.
The car is a 92 RX7 FD which has an crate LS3 and TR6060 gearbox. Has a custom mounted dodge viper rear diff as well.
It is running twin precision 6766 ball bearing turbos with 46mm wastegates.
Have a largeish cam in there and stiffer valve springs. Also running twin walbro 450 pumps.
Rotating assembly is currently stock so not going to go too crazy on boost, probably around 7-8psi maybe 9 for a high boost setting.
So the 4 black grounds from the Xtreme header I run to the engine to ground or can they be chassis? I take it they can't be grounded in the same place?
Ground out - how do I wire it to the sensors?
Sounds like its going to be a very stout setup, what are you planning to use it for?
Have you got any links on the layout of the OEM loom you can put up? I haven't had a huge amount of luck finding anything reliable. There should be power ground wires already in it that head to a grounding ring terminal that gets attached to the engine block, there are what you'd connect the power ground wires of the ECU too.
It's a similar story with the sensor grounds, there will be a sensor ground wire in the ECU header that will branch out and head to all the sensors already, and you should be able to re-use this.
Mostly street, if i can get the power to the road. Maybe a bit of drag and top speed runs too.
The spreadsheet i attached in my first post has the pin out for the OEM loom, do you need a wiring diagram?
OK, so i just need to know which sensor ground is which and wire it to the correct one, or does it not really matter which ground i use on the Xtreme header?
Yeah, if you had any links to a complete pin-out for your ECU, or wiring harness diagrams, that would be excellent. I'll have a bit of a google now and see what I can track down too.
On the Xtreme the black grounds need split between the head and the block, I believe they specify that you don't use a chassis ground.
As for the sensor earths (green wires), they aren't specific as to where they are used as they are grouped together in the Link sold loom.