Grounding Mod thread.

sajohnson · 03-02-2002, 03:26 AM

I just completed the 'grounding mod'. Man, what a difference!

My WRX had a bad stumble or hesitation between 4 and 6,000 rpm even when fully warm. After adding several ground wires the stumble is gone!

I added 5, 12 gauge, THHN ground wires: one to each strut tower, one to each side of the intake, and one to the firewall. The last 3 are existing factory ground points. All 5 wires terminate at a two-piece solid copper lug on the neg. battery terminal. I used "Copper Shield" anti-oxidant on all connections. Also, I found that the factory ground at the firewall was done over painted metal (lame), so I cleaned that up.

I am amazed at the difference this mod made. I was skeptical but figured the cost was minimal and I had nothing to loose.

kurichan · 03-02-2002, 03:38 AM

Okay -- I am skeptical. Where can I get detailed info about this?

mid9s · 03-02-2002, 03:41 AM

I would like to know more also

sajohnson · 03-02-2002, 03:45 AM

http://www.i-club.com/forums/showth...threadid=141932

Also see the thread, "Stumble During Acceleration"

titsataki · 03-02-2002, 09:18 AM

link does not work??

T.

Zahnster · 03-02-2002, 12:39 PM

Try this link:

http://i-club.com/forums/showthread.php?threadid=141932

03-02-2002, 01:17 PM

donrgolf

user name
Us Texans actually do have a few tech posts!

IMPREZIV · 03-02-2002, 01:17 PM

Just did this mod yesterday as well. Holy S, what a difference!

Here is how we did it, and I will post pics soon.

2 gauge wire from Neg battery terminal to ground distributor block. 8 gauge wire from block to 5 separate ground points. Hesitation is gone, accel surges at low rpms, gone. And for those of you who follow my compaining, my EVC-4 is now functioning properly at all boost and RPM levels.

Entire cost of project, $40.
Time under the hood, 1-2 hours.

One of, if not the best mod I have ever done. Highly recommended, especially for those experiencing accel surges and bucking.

Good luck, speed safely.

Pete

kurichan · 03-02-2002, 02:12 PM

And this works for ALL '02 WRXs, not just chipped cars, right?

dwx · 03-02-2002, 02:26 PM

Jorge (riftswrx) did this a few months ago as well. www.projectwrx.com has a writeup on it. I've never heard any bad things come from doing this mod to any level of car.

BIGSKYWRX · 03-02-2002, 04:51 PM

sajohnson,

As a electrically challenged person (ECP

), I am unfamiliar w/ the acronym THHN when refering to ground wires, could you please explain? Also unfamiliar w/ your 2 piece solid copper lug you mention. What did you use for ends at your contact points?

Sorry for all the questions, but an also experience a slight hesitation occasionaly and would like to end it.

Thanks in advacne,

Big Sky

Conduit · 03-02-2002, 07:18 PM

THHN is the stiff, solid core wires used in home wiring. It's cheap, and can be had at most any home improvement store. Watch the jacketing on heat sources, it doesn't like heat. I have a 1000 foot spool in my car room as we speak

Concillian · 03-02-2002, 07:22 PM

THHN = Thermoplastic High Heat Nylon

It refers to the insulation on the wire, which is spec'ed to 90 C. It's mostly used by builders and such.

Most silicone insulated welding wire is also spec'ed to 90 C.

spd wgn · 03-02-2002, 09:48 PM

there's probably a wide range of wire you can use...
I used 10 gauge primary (stranded) automotive wire and soldered and crimped ring connnectors

datdudedennis · 03-03-2002, 01:08 AM

i did this mod today. i used 8 gauge audio wire crimped to terminal connectors. my mods are mbc, intake, and exhaust. i dind't notice much, i did experience though that it was easier to take off from a stop in 2nd gear and i can shift to fifth at 38mph or above and not get vibrations instead of 40mph and above. but the weather could have played a roll.

dennis

mynew02 · 03-03-2002, 01:31 AM

You wouldn't have noticed anything if you didn't have a problem to begin with. This is not a performance mod and you will not notice better starts. What you may have noticed is better performance due to resetting your ecu.

It only fixes a problem with a mild hesitation while accelerating throught 3-5K rpm.

If you are having problems with a slight jerk at 3-5K rpm do this mod. It works... fixed me anyway.

-Jonathan

sajohnson · 03-03-2002, 01:50 AM

The THHN I used is stranded and gas and oil resistant.

The insulation would be more important if we were running +12 volt supply wiring. From a safety standpoint since these are Neg. (-) ground wires, they could be bare. From a funtional standpoint though, bare wire might be problematic because any place the wire came in contact with metal would become a potential ground point.

mcu81 · 03-03-2002, 12:40 PM

one far out crazy question about this. they say if you get struck by lightning that it will ground out threw your rubber to the ground. is this going to help or hurt this cause? weird, wild, question just was thinkin bout this.........

PDG · 03-03-2002, 12:47 PM

Rubber is an insulator, the lightning will not ground out through the tires.

If lightning hits your car it will travel on the outside of the car's 'shell' of an metal enclosure.

Goodies learned from the Boston Museum of Science.

mcu81 · 03-03-2002, 01:09 PM

thanks PDG.....good good good.........

sajohnson · 03-03-2002, 03:35 PM

Well there's one less thing to worry about!

Somber · 03-05-2002, 11:32 PM

here is my story...

my car was "surging" a bit at low partial throttle in the 3-5K RPM range... I am not in this range very often without being near WOT, so I hardly ever noticed it, but every once in a while...

when I read about this "miracle mod", I went out and purposefully searched for the surging... after a bit, I found that I could produce it in a very repeatable manner... 3200 RPM, low throttle, mild acceleration - I would get a surging not unlike feathering the throttle...

I have done an ECU reset since noticing this issue, and it had no effect, so I decided to give this mod a shot and see what effect it had...

I didn't want to run 5 wires without knowing that I really needed to, so I started with a single 8gauge woven cable from a local stereo shop that I cut to length and crimped on eyelets... I connected this wire from the bolt through the negative ground cable on the battery, to the drivers side ground bolt on top of the manifold on the engine... I then went out for a test run... there was a noticeable improvement - the surging still there, but much more faint, almost imperceptible...

I then made a second cable and ran it from one of the passenger side strut top mount bolts to the passenger side manifold ground bolt... went for a second test run:

GONE!!! all traces of the surging gone, I worked really hard at trying to reproduce any surging, and could not under any condition...

I'm going to drive for a few more days and make sure I don't suffer any additional surges...

after that, I think I'll remove the wires and see if it comes back (tho I'm almost afraid to)...

just a bit more information for everyone to think about...

I do not have any better idea about what this does, other than good grounding is a good thing, but it made a marked improvement in my car...

Paul

IMPREZIV · 03-06-2002, 12:00 AM

Hey Paul
I had a similiar experience, but unfortunately and came back and went away again, and now its back. That leads me to believe that this is the way in which to fix the problem, now I have to just isolate exactly where the problem is stemming from pay special attention to grounding that. I will keep everyone up to date as this progresses.

Good luck
Pete

Somber · 03-06-2002, 12:21 AM

well maybe I won't "unground" for the sake of science... LOL

please keep me in mind when you do figure out what worked...

sajohnson · 03-06-2002, 12:41 AM

Whatever gauge wire you use and wherever you decide to add extra grounds make sure you use some type of conductive inhibitor. Try these links:

http://tnbsun4.tnb.com:8080/tnbcat/t...alog_home_page

http://tnbsun4.tnb.com:8080/tnbcat/t...ch_indic_flg=T

If they don't work, I used Thomas and Betts Kopr-Shield (P/N CP8-TB). Their site is

www.tnb.com

03-02-2002, 03:26 AM	#1
sajohnson Scooby Specialist Member#: 6140 Join Date: Apr 2001 Chapter/Region: MAIC Location: Middletown, MD, USA Vehicle: 2002 WRX 5MT Sedan WR Blue. Cobb Stage 2	Miracle Mod! I just completed the 'grounding mod'. Man, what a difference! My WRX had a bad stumble or hesitation between 4 and 6,000 rpm even when fully warm. After adding several ground wires the stumble is gone! I added 5, 12 gauge, THHN ground wires: one to each strut tower, one to each side of the intake, and one to the firewall. The last 3 are existing factory ground points. All 5 wires terminate at a two-piece solid copper lug on the neg. battery terminal. I used "Copper Shield" anti-oxidant on all connections. Also, I found that the factory ground at the firewall was done over painted metal (lame), so I cleaned that up. I am amazed at the difference this mod made. I was skeptical but figured the cost was minimal and I had nothing to loose. Last edited by sajohnson; 03-11-2002 at 11:35 PM.

03-02-2002, 03:45 AM	#4
sajohnson Scooby Specialist Member#: 6140 Join Date: Apr 2001 Chapter/Region: MAIC Location: Middletown, MD, USA Vehicle: 2002 WRX 5MT Sedan WR Blue. Cobb Stage 2	Check Here http://www.i-club.com/forums/showth...threadid=141932 Also see the thread, "Stumble During Acceleration"

03-02-2002, 01:17 PM	#7
Tex-WReX2 Guest Member#:	search under donrgolf user name Us Texans actually do have a few tech posts!

03-03-2002, 01:50 AM	#17
sajohnson Scooby Specialist Member#: 6140 Join Date: Apr 2001 Chapter/Region: MAIC Location: Middletown, MD, USA Vehicle: 2002 WRX 5MT Sedan WR Blue. Cobb Stage 2	Wire The THHN I used is stranded and gas and oil resistant. The insulation would be more important if we were running +12 volt supply wiring. From a safety standpoint since these are Neg. (-) ground wires, they could be bare. From a funtional standpoint though, bare wire might be problematic because any place the wire came in contact with metal would become a potential ground point.

03-03-2002, 03:35 PM	#21
sajohnson Scooby Specialist Member#: 6140 Join Date: Apr 2001 Chapter/Region: MAIC Location: Middletown, MD, USA Vehicle: 2002 WRX 5MT Sedan WR Blue. Cobb Stage 2	mcu81 Well there's one less thing to worry about!

03-02-2002, 03:38 AM	#2
kurichan Scooby Newbie Member#: 8282 Join Date: Jul 2001 Vehicle: 2002 WRX Sedan	Okay -- I am skeptical. Where can I get detailed info about this?

03-02-2002, 03:41 AM	#3
mid9s Scooby Newbie Member#: 7777 Join Date: Jun 2001 Location: alexandria, VA Vehicle: 2002 impreza WRX Blaze Yellow	I would like to know more also

03-02-2002, 09:18 AM	#5
titsataki Scooby Specialist Member#: 4402 Join Date: Feb 2001 Chapter/Region: NESIC Location: New Haven, Connecticut Vehicle: 2005 WRX STi(gone) CGM (and missing it)	link does not work?? T.

03-02-2002, 12:39 PM	#6
Zahnster Scooby Specialist Member#: 2918 Join Date: Nov 2000 Location: Simi Valley, CA, USA Vehicle: 2002 Impreza WRX Silver Sedan	Try this link: http://i-club.com/forums/showthread.php?threadid=141932

03-02-2002, 01:17 PM	#8
IMPREZIV Scooby Specialist Member#: 862 Join Date: Feb 2000 Location: NY	Just did this mod yesterday as well. Holy S, what a difference! Here is how we did it, and I will post pics soon. 2 gauge wire from Neg battery terminal to ground distributor block. 8 gauge wire from block to 5 separate ground points. Hesitation is gone, accel surges at low rpms, gone. And for those of you who follow my compaining, my EVC-4 is now functioning properly at all boost and RPM levels. Entire cost of project, $40. Time under the hood, 1-2 hours. One of, if not the best mod I have ever done. Highly recommended, especially for those experiencing accel surges and bucking. Good luck, speed safely. Pete

03-02-2002, 02:12 PM	#9
kurichan Scooby Newbie Member#: 8282 Join Date: Jul 2001 Vehicle: 2002 WRX Sedan	And this works for ALL '02 WRXs, not just chipped cars, right?

03-02-2002, 02:26 PM	#10
dwx Scooby Guru Member#: 8343 Join Date: Jul 2001 Chapter/Region: MWSOC Location: Atlanta, GA Vehicle: 2006 Impreza WRX 1x PS F250	Jorge (riftswrx) did this a few months ago as well. www.projectwrx.com has a writeup on it. I've never heard any bad things come from doing this mod to any level of car.

03-02-2002, 04:51 PM	#11
BIGSKYWRX Scooby Guru Member#: 7958 Join Date: Jul 2001 Location: Plains of Eastern Montana Vehicle: 09 GH B+	sajohnson, As a electrically challenged person (ECP ), I am unfamiliar w/ the acronym THHN when refering to ground wires, could you please explain? Also unfamiliar w/ your 2 piece solid copper lug you mention. What did you use for ends at your contact points? Sorry for all the questions, but an also experience a slight hesitation occasionaly and would like to end it. Thanks in advacne, Big Sky

03-02-2002, 07:18 PM	#12
Conduit Scooby Specialist Member#: 6162 Join Date: Apr 2001 Chapter/Region: South East Location: Orlando, FL. USA Vehicle: 2002 WRX MBP, 1st WRX Ever in FL.	THHN is the stiff, solid core wires used in home wiring. It's cheap, and can be had at most any home improvement store. Watch the jacketing on heat sources, it doesn't like heat. I have a 1000 foot spool in my car room as we speak

03-02-2002, 07:22 PM	#13
Concillian Scooby Specialist Member#: 4414 Join Date: Feb 2001 Location: Dublin, CA Vehicle: 2002 WRX Sedan Midnight Black	THHN = Thermoplastic High Heat Nylon It refers to the insulation on the wire, which is spec'ed to 90 C. It's mostly used by builders and such. Most silicone insulated welding wire is also spec'ed to 90 C.

03-02-2002, 09:48 PM	#14
spd wgn Scooby Newbie Member#: 8571 Join Date: Jul 2001 Location: arlington VA Vehicle: 2002 wrx	there's probably a wide range of wire you can use... I used 10 gauge primary (stranded) automotive wire and soldered and crimped ring connnectors

03-03-2002, 01:08 AM	#15
datdudedennis Scooby Specialist Member#: 3928 Join Date: Feb 2001 Location: houston, tx, usa Vehicle: 2002 WRX sedan WRB use to be MBP	i did this mod today. i used 8 gauge audio wire crimped to terminal connectors. my mods are mbc, intake, and exhaust. i dind't notice much, i did experience though that it was easier to take off from a stop in 2nd gear and i can shift to fifth at 38mph or above and not get vibrations instead of 40mph and above. but the weather could have played a roll. dennis

03-03-2002, 01:31 AM	#16
mynew02 Scooby Specialist Member#: 13726 Join Date: Dec 2001 Location: Maryland Vehicle: 2002 WRX - 264 AWHP ION-Turbo&LINK 12.83@106	You wouldn't have noticed anything if you didn't have a problem to begin with. This is not a performance mod and you will not notice better starts. What you may have noticed is better performance due to resetting your ecu. It only fixes a problem with a mild hesitation while accelerating throught 3-5K rpm. If you are having problems with a slight jerk at 3-5K rpm do this mod. It works... fixed me anyway. -Jonathan

03-03-2002, 12:40 PM	#18
mcu81 Scooby Specialist Member#: 5796 Join Date: Apr 2001 Chapter/Region: MWSOC Location: Motown Dub V Vehicle: 2007 STI, 07 Tundra 99RS	one far out crazy question about this. they say if you get struck by lightning that it will ground out threw your rubber to the ground. is this going to help or hurt this cause? weird, wild, question just was thinkin bout this.........

03-03-2002, 12:47 PM	#19
PDG Scooby Newbie Member#: 11049 Join Date: Oct 2001 Location: Chelmsford, MA Vehicle: 02 WRX, BLACK WAG Somewhere around stage 4	Rubber is an insulator, the lightning will not ground out through the tires. If lightning hits your car it will travel on the outside of the car's 'shell' of an metal enclosure. Goodies learned from the Boston Museum of Science.

03-03-2002, 01:09 PM	#20
mcu81 Scooby Specialist Member#: 5796 Join Date: Apr 2001 Chapter/Region: MWSOC Location: Motown Dub V Vehicle: 2007 STI, 07 Tundra 99RS	thanks PDG.....good good good.........

03-05-2002, 11:32 PM	#22
Somber Scooby Newbie Member#: 5118 Join Date: Mar 2001 Location: Oklahoma City, OK, US	another satisfied modder here is my story... my car was "surging" a bit at low partial throttle in the 3-5K RPM range... I am not in this range very often without being near WOT, so I hardly ever noticed it, but every once in a while... when I read about this "miracle mod", I went out and purposefully searched for the surging... after a bit, I found that I could produce it in a very repeatable manner... 3200 RPM, low throttle, mild acceleration - I would get a surging not unlike feathering the throttle... I have done an ECU reset since noticing this issue, and it had no effect, so I decided to give this mod a shot and see what effect it had... I didn't want to run 5 wires without knowing that I really needed to, so I started with a single 8gauge woven cable from a local stereo shop that I cut to length and crimped on eyelets... I connected this wire from the bolt through the negative ground cable on the battery, to the drivers side ground bolt on top of the manifold on the engine... I then went out for a test run... there was a noticeable improvement - the surging still there, but much more faint, almost imperceptible... I then made a second cable and ran it from one of the passenger side strut top mount bolts to the passenger side manifold ground bolt... went for a second test run: GONE!!! all traces of the surging gone, I worked really hard at trying to reproduce any surging, and could not under any condition... I'm going to drive for a few more days and make sure I don't suffer any additional surges... after that, I think I'll remove the wires and see if it comes back (tho I'm almost afraid to)... just a bit more information for everyone to think about... I do not have any better idea about what this does, other than good grounding is a good thing, but it made a marked improvement in my car... Paul

03-06-2002, 12:00 AM	#23
IMPREZIV Scooby Specialist Member#: 862 Join Date: Feb 2000 Location: NY	Hey Paul I had a similiar experience, but unfortunately and came back and went away again, and now its back. That leads me to believe that this is the way in which to fix the problem, now I have to just isolate exactly where the problem is stemming from pay special attention to grounding that. I will keep everyone up to date as this progresses. Good luck Pete

03-06-2002, 12:21 AM	#24
Somber Scooby Newbie Member#: 5118 Join Date: Mar 2001 Location: Oklahoma City, OK, US	well maybe I won't "unground" for the sake of science... LOL please keep me in mind when you do figure out what worked...

03-06-2002, 12:41 AM	#25
sajohnson Scooby Specialist Member#: 6140 Join Date: Apr 2001 Chapter/Region: MAIC Location: Middletown, MD, USA Vehicle: 2002 WRX 5MT Sedan WR Blue. Cobb Stage 2	Good Connections Whatever gauge wire you use and wherever you decide to add extra grounds make sure you use some type of conductive inhibitor. Try these links: http://tnbsun4.tnb.com:8080/tnbcat/t...alog_home_page http://tnbsun4.tnb.com:8080/tnbcat/t...ch_indic_flg=T If they don't work, I used Thomas and Betts Kopr-Shield (P/N CP8-TB). Their site is www.tnb.com

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