DEZERTE

What in the world is a grounding kit, or grounding your car or whatever. Ive heard of it from like 2 different people but I have no clue what it is.. fill me in?
Josh

oakback

Our cars are old, and the wiring is old. The way I understand it is that the grounding lets things work the way they should work, without being held back by bad connections.

And you don't need a "kit," just some wire and connectors. grounding how-to

totallimmortal

Grounding kits add and replace the ground wires that ground the engine and everything underthe hood to the negative side of the batt. One way to think about it is that the sparke plug wires are the (+) positive wire for the plug and the block acts as the (-) negative wire. So even with good plugs, wires and coils, the spark can only be a strong as the weekest link which can sometimes be old or broken grounding wires. the better everything is ground you get better spark and smother operation, IMHO kits are a waste of money, jusy buy some heavy gauge like amp power wire or battery cablle and make your own

DEZERTE

.

YearsOfDecay

Basically, you are running wires from various points on the car, engine block, ecu, electronics, ect, to the frame/negative battery post to "ground" stray or errant voltage within the electrical system of the car.

Grounding your car can free up a little bitty bit of horsepower... but it doesn "Give" you any... the HP was already potentially there but electrical interference was causing loss to the system, usually its most noticable at high RPM and at idle.

The biggest thing I noticed was that it "smoothed" everything out.. the car ran, idled and pulled much more smoothley. I aslo had some trouble with breakup at high RPM's in the ignition system, fixed that right up. (I run a Haltech, so getting a good CAS signal is real important)

SureShot

The ECU uses low voltage signals from sensors (like the TPS, the boost sensor, & the O2 sensor).
Most of these sensors have their own ground wires, but if the primary grounds are the least bit weak, the ECU grounds try to carry the noisy spark and alternator loads also. The ECU tries to compensate & goes nuts.
The cheesy firewall to bell housing ground just clips on. Replacing it with a heavy gage wire with eyelets & bolts is a good start.
I have also seen improvements by adding a ground from the spark coil mount to the alternator frame.

The trick is bright shinny metal-to-metal contact.

fastrotaries

add a ground from the block to the (-) battery terminal, or block to chassis. The O2 sensor grounds itself through the exhaust so make sure that there is good groung there. The stock one is on the drivers side muffler. I added one just behind the cat.

jon88se

Spend a day doing this, it's worth it...first of all, before you install a universal kit, an already-made kit (HKS circle earth) or make your own (so easy), be SURE to open up a repair manual and find the major OEM grounds. Chances are they are caked in years of dirt grime and corrosion. Take them apart, clean with some degreaser and a wire brush and get a good metal to metal contact. Then add your additional grounds. Hit a local car stereo shop for a distribution block and some 10 gauge power wire , anything thicker is just for show, these are ground wires and shouldn't carry much signal/current at all. The wire is available in loads of colors (smoked looks cool, red does not hehe). They will also sell you the connectors and the gold plating is, again, just for show. Then hit radioshack and pick up some heatshrink, a crimping tool, some solder and a cheap soldering iron. Measure all your lengths first, then procede to make your wires by crimping and soldering connectors then using heatshrink around the ends. Connect the negative battery post to the distribution block then run your ground wires from the block to the following points (worked best for me):

-Strut tower
-Alternator bracket
-BAC bracket
-Firewall


Make sure you have some zip ties to make everything nice and neat. Once I restarted the car my cold idle surge disappeared (the cold idle would surge from 1000-1500 rpm for 30 secs) and my batt. voltage was slightly better and much more consistent once the car was warm and idling as it used to read just over 12.5 thanks to the UR pulley. Now it pulls 13V on a warm idle @ 800 rpm. In addition, the cold-engine 3800 rpm hesitation was gone. My motor only did it when cold and now it was fixed. All in all, this is well worth an afternoon to fix some old-car-gremlins. For the TII people out there, the HSK kit comes with instructions for ground points

DEZERTE

Thanks for the helpful posts, really i didnt expect this much usefull information..
What part of the FSM shows all the major grounding points on the car? I downloaded the FSM if the links dont work and i can host the chapter on this thread if you tell me where it is.

ddub

Just follow the grounding how-to that's what I did, it works great and my hesitations went away after that.

SDrotary-FC

i got better midrange when i put in mine

evileagle

iTrader: (1)

Can someone pleaaaaase remake that grounding how to with some decent pictures?

I am almost afraid to look at that thread anymore thinking about what people might be grounding!

rs_1101

yea when i regrounded my car i was worried cuz i didnt have the kick in the pants feeling, but my trap speeds mysteriously went up..?
i think its smoother power band. much smoother

Kenteth

Edit: nm
Edit: ok ill say something

You can buy decent grounding bus bars for cheap at most hardware stores. That will save you the $200 hks bullshit. Just buy some decent wire and some ends and you got it for around $50

evileagle

iTrader: (1)

Oh no, don't get me wrong, I did my own grounding, but I look at that and even though I know what it's talking about, the pictures are less than helpful. I worry for some of the... less knowledgeable... forum members.

Madrx7racer

i would appreciate beter quality pictures......I need to check the grounding to my coils...........ASAP.

Junia

My friend's FC once caught on started smoking and almost caught on fire because of that POS ground clip that goes to the engine/tranny to the firewall.

Icemark

That means the engine lost its main ground and was trying to ground the whole engine and tranny and everything through the tranny ground.

That wire is a backup/ secondary ground and not for any major current.

NZConvertible

There's really no need to do even that. The whole chassis can be used to do the same thing for free. I don't think a central grounding point, whether DIY or from a ridiculously over-priced kit, is going to make any difference.

That "POS clip" was not at fault. That usually happens when someone forgets to reinstall the engine's main ground wire.

IMO people get way too excited about grounding, and go over the top for no good reason. You have to keep in mind that other than the starter motor (which already has a large ground wire), we're not talking about a lot of current here. Two or three extra 8GA wires is really all you need. These people adding half a dozen 4GA wires are kidding themselves if they think that's needed. All you're doing is wasting money. And don't get me started on those damn kits, which should only be purchased by those who actually like the look a big colourful wires all over their engine bay, as opposed to people who just want to cure a few electrical gremlins.

WAYNE88N/A

NZ's right on the money here guys...Not trying to brag, but I've got almost 20 years under my belt as an aircraft electrician, and this grounding frenzy that's swept the rx-7 community is all a crock...CLEAN UP the grounds you have on the car, add a 12 or 14 gauge wire from the engine ground on the rear rotor housing to the firewall (find a spare bolt hole), but that should BE IT!!!The problem with Mazda's grounds are that they used the bolt threads/nutplate threads for the ground- you will never see this on an aircraft...The ground should be a ring terminal face bolted against a similar sized bare metal circular area on the chassis, with a washer under the bolt head...This is how you'll fix the grounds on our cars, not adding new ones...Something else I read up the thread a little ways said the grounds carry little or no current- this is not true- the negative wiring on a chassis grounded vehicle carries almost ALL the current, the current is used by the relays, solenoids, etc, and a smidgen returns to the power source through the positive wiring...current flows from NEG to POS, contrary to prevailing wisdom....That's why you'll see some negative cables that are larger than their positive conterparts in the same circuit....

incendui

Current flows from + to -, electrons flow from - to +. And as far as there being more current through the ground then from the power source, try reading this Kirchhoff's Current Law.

WAYNE88N/A

Ha ha, I was wondering when it was gonna start...We argued with the instructor forever in the electronics class also...think of it this way- there really is no real answer to this conundrum, and in any case it's too trivial to worry about much. Electricity is nothing more than electrons leaping from one atom's valence shell to another, at the speed of light or so...since the negatively charged electrons are "flowing" to the positively charged atoms, we can say that current flows from neg to pos...or, you can view it the other way around, it actually makes it easier to think pos to neg when troubleshooting a circuit...like I said, trivial at best...If our cars were a positive-grounded vehicle, the wiring would have to be bigger to carry the loads that the chassis metal itself normally carries- it gets complicated, I know...just keep in mind that current and voltage are two entirely different concepts (although they are measured inversely proportional to each other)...voltage readings are much easier to quantify & measure for troubleshooting purposes, that's why we use voltage numbers more often than not to troubleshoot wiring, even though it's not an entity that FLOWS...

Asphaultscry

Yup thats how I would describe it and I'm a electrician, you hit it right wayne88N/A.

Madrx7racer

any news on the grounding pics?

jon88se

I posted about the grounds carrying low current but look at the context of the sentence; basically I'm saying you don't need the huge 4 gauge wire everyone is using on various forums. Main grounds should carry a lot and are very important...but these additional grounds should only be carrying whatever "leftover" the OEM grounds may not be taking...correct? As in simply making up for the inefficiency of OEM grounds.