wb123

Ok this may sound stupid
And as I have been looking over all of the grounding diagrams and how to's I just have 1 question left...

Is it necessarry to have 6-7 grounds for an Rx7 ? Usually for many cars 1 ground from battery to body is good enough..
Now i know the performance of rx7's yada yada but is there any explanation for this or is this just a "monkey see. monkey doo.. type approach" to grounding...?

I am making a home made grounding kit, any suggestions or tips welcome...
Also I was just wondering what is not "good" to ground, like something that would blow your engine.

And also i hear people grounding their Downpipe and Catback.. why would this benefit?

And also, to those who grounded their ECU, how did you go about doing this ?


Please leave comments and suggestions.
THanks!

yuichiror

iTrader: (1)

http://www.rotaryresurrection.com/3r...st_ground.html

https://www.rx7club.com/showthread.p...=ground+damian

onesick7

yuichiror: thanks for the links. I wasn't even looking to do anything with my grounds but now I have another reliability mod to do! lol honestly though thanks cause that walkthrough is quick and easy.

yuichiror

iTrader: (1)

Actually the same thing happened to me. I happened to run across this in another thread and thought, "Hey, a cheap "reliability mod" that's easy to do".

GoodfellaFD3S

iTrader: (213)

Chris, if you're going to keep posting, how about you update this debacle of a thread?

https://www.rx7club.com/bad-fugly-members-185/issues-me-seller-chitownr1-midwestbest-mwb-drifted7-tyrant-tt-615307/page7/

bryant

looks like someone needs to make good!

wb123

i HAVE read all of those links/posts, they dont really answer my specific questions...

rynberg

You need to understand basic wiring, it has nothing to do with an FD. EVERY car has multiple grounds.

scotty305

iTrader: (2)

Don't think of it as multiple grounds. Think of the chassis as the largest wire on the car. All the grounds connect to it eventually. Using five or six small (and short) wires to connect to the chassis is usually a better idea than using one or two large (and long) wires that connect directly to the battery's negative terminal (which would be heavy, expensive and difficult to route).

-s-

rynberg

Thanks for clarifying and expanding, Scotty.

wb123

Awesome great explenation scotty!

Ok just 2 more clarifications please... When connecting ground wires to the DP and Cat back, how do i go about doing this so the wiring doesn melt?

Also,
If i want to ground the eCU would i have to dril any holes through the fire wall? and do i put the ground on the actual ecu and connect that to the chasis?

rynberg

:WTF: Just use the factory grounds.....the ecu and the exhaust system are already grounded....the exhaust system ground goes between the bolt head and the flange.

RX7LINK

iTrader: (3)

^^ +1

why would u want to ground to the DP when you have the whole chassis to use if needed?

Monkman33

iTrader: (28)

You are grounding between the downpipe and the chassis. Basically, you are trying to eliminate any weird electrical resistances. if the electricity flows smoothly, then everything works reliably. and your ignition likes things to work right.

DaveW

The FD electrical system, including the ECU and the engine sensors, is (apparently) particularly sensitive to minute voltage variations. This means that a couple of millivolts lost in bad connections can throw off the very sensitive calibrations that keep the fuel mixtures in tune with the throttle opening, intake-air temperature, intake manifold pressure, O2 sensor reading, etc., all sent via voltage values to the ECU.

"Ground loop" voltage is a way for electronic whiz kids to describe voltage variations between one ground point and another. If these voltage variations between ground points become large enough to exceed the tolerance built into the system, bad things can start to happen. In the FD's case it is usually the 3K (or other) hesitation, but it can be much worse if the voltage discrepancy is large enough.

In our fatigue-test lab, we have multiple heavy gauge grounds between the various parts of (especially) control systems to try to eliminate voltage spikes and other problems that can cause a test machine to shut down, or, even worse, go out of control and break expensive, irreplaceable, stuff.

One can never have too many or too heavy-gauge ground paths, but you can certainly have too few.

M104-AMG

iTrader: (8)

My 1993 Mercedes 500E has over 4-major ground points, and over seventy grounds total from the factory!

It even has an over-voltage/surge-protector module, that I'm thinking about integrating into the engine ECU of the FD . . .

:-) neil