Grounded TB mod?

[HammerZ71]

Anybody running this on their Hemi?

When I first heard about it I was skeptical as hell, so I tried it just to disprove it. I gotta admit however, that I can see a difference in throttle response...

[AWE Daniel]

Whatchu talking bout?

[Onk]

Do my eyes deceive me or it that really Ed?

[ORT]

..........

[HammerZ71]

Originally Posted by ORT Lots of guys are running it including me. There is a long thread about it on DT.

To be honest Teach, I had read something about it on a Jeep forum not long after the WKs came out and had the Hemi, but really didn't pay much attention to it.
But it's been picking up a lot of press on a LOT of forums recently. I thought "now way could this make a difference, the TB is grounded already or it wouldn't operate". Well I was wrong. I happened to have a brand new 24" pre-terminated 4 AWG wire in the garage I keep around for connecting batteries for either 24v trolling motor use or for extra winch power. So I hooked it up this morning from the TB to a sidewall ground (wasn't long enough to hit the neg battery post without running over the engine). First thing I noticed was my normal 200 RPM fluctuation at idle was GONE. Idle needle held steady as a rock. I'm pretty sure I can sense a better throttle response, although I won't 100% rule out the placebo effect. Now on deceleration there is no doubt, I feel a lot more response when I take my foot off the gas.
Haven't had a chance to run the truck outside of my neighborhood, which means no WOT or even speeds over about 40 mph, so as I get to test it hitting the gas hard, I'll better know about response on acceleration.

But to be honest, for the cost of the mod my rock steady idle alone is worth leaving the wire there (and it's basically a freeby as I'm sure most people have a piece of wire laying around - and you don't need 4 AWG, I just happened to have one pre-made at about the right length).

This is one y'all need to try...

And yeah Kevin, it's me. I ain't been on here at all or even the "other" forum I run nearly as much as I used to be. Got laid off the day after Thanksgiving when the place I worked for declared bankruptcy. I've got a few offers up home in GA, but my mom's health isn't good enough for me to leave her in FL. So I've been running around picking up as much work as I can doing about anything. I've done welding, re-done a boat right down to ripping everything out, fiberglassing, sanding, painting, wiring and installing everything from bilge pump to lights. Been giving golf lessons here and there and done a few truck mods for people. So I've been just a bit busy, LOL...

[HammerZ71]

Oh sorry, back to the mod.

Basically you take a piece of wire, 12 gauge would probably be fine or anything thicker, and loosen one of the bolts holding the throttle body on (there are four, one in each corner on the face). Connect the other to chassis ground or the negative battery terminal and you're done. Five minutes if you have a CAI as the bolts are right there in front of you, 10-20 minutes if you have to either finagle a way around the "Hemi Hat" or remove it to get it out of the way.

I just talked with a buddy of mine who is a retired electrical engineer with 17 years at NASA via text message and he told me why this works. It basically has to do with getting rid of electrical noise (same way as when your stereo whistles on acceleration and you fix it by increasing the ground). Also it dissipates static electricity that builds on the metal body of the TB. Normally this static builds until it is higher than the voltage coming into the TB from the battery and then it shoots out the TB ground wire through the stock plug. However it won't do it until it builds to a point that it can take the path of least resistance. With the housing grounded to chassis, this static never forms.

Makes sense I guess. Anyway this guy knows a hell of a lot more about electricity than I do. But I do know there is a perceptable difference, especially in the way my truck idles...


I am not going to do it on my Grand Cherokee (4.7 HO) as it is not "fly-by-wire" and I can't see any benefit on a TB with a physical throttle cable, unless you've heard anything, Teach???

[AWE Daniel]

I am gonna go do this right now!

[HammerZ71]

Here you go Daniel: (sorry for the glare in the pic)



then just run it to either the (-) post or one of the chassis ground bolts on the side wall. I went right to where I have my off-road lights grounded. My lights work, so I know it's a good ground.



A couple zip-ties along the fire wall and side wall to keep it out of the way and you're done...

[ORT]

........

[AWE Daniel]

Just finished it up, i do have a really smooth feeling idle now (ultragauge shows about a +/- 30 rpm bounce), and I think it helped the response a little. Pretty simple mod to do, I also used 4ga since I have 50ft of that stuff laying around. I grounded it close to the battery, up near the firewall, but I didnt take a picture of that, its a lot like where that smaller negative wire grounds from the battery, but closer to the firewall. I sanded it up with sandpaper real good to get a good ground.

Thanks for the pics Hammer!