What is the point of a grounding mod/kit?

[jjs316]

I see it alot, and have seen actual kits you can buy. What is the reasoning behind a grounding mod?

[Sarra]

On my 1998 LGT, it smoothed out power delivery and idle. I could always tell when a wire came loose (homemade kit) because it would idle like crap.

[birukun]

Modern cars with ECUs have sensors placed all over the engine. These sensors translate what ever they are measuring into voltage. This voltage is compared against a reference point often referred to as the ground reference. Cars use the chassis as a ground reference since there is no 'earth ground' due to the tires insulating the car from the earth. Ships also use a 'floating ground reference' since the 'earth ground' is always changing as you go through water.

A grounding kit will help your sensors maintain a good ground reference that is the same as what is the ECU is seeing. This insures that +1.3volts read at a sensor looks like +1.3volts at the ECU. If the ground in the chassis is marginal, it may fluctuate enough to cause a difference in the two.

Auto manufacturers will use the least amount of materials to build a car to cut weight and reduce production costs. Some smart engineer somewhere decided a long time ago that the chassis would make a good ground, instead of running two wires between each sensor to the ECU. This works great until the chassis is subject to all the environmentals, vibration, and flex that causes the points that tie it all together to become electrically questionable. (a few years on the road) Add the lighting system that uses the same method, and things can get even quirkier.

A good grounding kit will overcome these changes by providing a good ground reference.

The ECU and TCU (A/T tranny) use sensors and many have reported smoother idle, smoother shifts, and increased throttle response when adding a grounding kit.

Just my $.02 in the condensed version......

[Grafton]

Modern cars with ECUs have sensors placed all over the engine. These sensors translate what ever they are measuring into voltage. This voltage is compared against a reference point often referred to as the ground reference. Cars use the chassis as a ground reference since there is no 'earth ground' due to the tires insulating the car from the earth. Ships also use a 'floating ground reference' since the 'earth ground' is always changing as you go through water.

A grounding kit will help your sensors maintain a good ground reference that is the same as what is the ECU is seeing. This insures that +1.3volts read at a sensor looks like +1.3volts at the ECU. If the ground in the chassis is marginal, it may fluctuate enough to cause a difference in the two.

Auto manufacturers will use the least amount of materials to build a car to cut weight and reduce production costs. Some smart engineer somewhere decided a long time ago that the chassis would make a good ground, instead of running two wires between each sensor to the ECU. This works great until the chassis is subject to all the environmentals, vibration, and flex that causes the points that tie it all together to become electrically questionable. (a few years on the road) Add the lighting system that uses the same method, and things can get even quirkier.

A good grounding kit will overcome these changes by providing a good ground reference.

The ECU and TCU (A/T tranny) use sensors and many have reported smoother idle, smoother shifts, and increased throttle response when adding a grounding kit.

Just my $.02 in the condensed version......
bravo
+1 that explanes why i saw a much smoother idle after i put mine on

[birukun]

I forgot to mention that often the worst offenders are sensors that use a ground wire that connects to the chassis or engine but in a manner that causes the fluctuations - MAF sensors are a big one since they are often embedded in a plastic non-conducting tube and require an extra wire.

There was a series of Nissan SR20DE motors that really come to life with an additional ground for the MAF sensor......

[1-3-2-4]

I hear about people always saying that they can notice the car idles much smoother? wow is it really that noticeable? I always thought $800 (inset random number) for a grounding kit was too over the top.

[Sarra]

I spent like $10 on my kit, bought some wire and some ring terminals and had at it. It was ghetto, really, but it worked.

[2.5GT]

i spent another $15 more on a universal kit on ebay and its pretty goood :eek:

[A1Fiddler]

I spent $5 for wire and $5 on a box of connectors. Worked well.

[LegacyRob]

I made my own for around $40 but i used fancy speaker wire, and heat shrink all connections.

[track8]

Birukun, that may be the best, most logical explanation I've ever seen regarding "grounding kits".

I've added grounds to most of my cars in the recent past and while Ive never detected any change attributable to them, I suspect that it's likely the redundancy may stave off future, frustrating diagnoses, as old ground leads deteriorate over time.

I too just buy good, car audio quality wire and connectors and create more grounds.

[Huffer]

Grounding kits are definitely worth the time on an older car... every version of Subaru that I've seen has consistently better grounds each generation. Not by much, but there's an improvement.

I just have to get off my ass and buy the parts and do eet...

[Grafton]

jj if you find some 8 ga ring termnals i'll sell you some 8 ga wire and help you make a kit for your car.
~$7 for the wire you'll need