Well, I did this mod the other day. I can feel a little bit quicker throttle response and smoother shifts. I used 10 gauge wire and ran it to the driver side and grounded it to the frame.

 

You know John, I hear ya. I'm the same way. I want to know WHY things are. Unfortunately, I'm not that knowledgable when it comes to this sort of stuff. However, like Hammer has tried, I took the ground wire off, and instantly had a rougher idle. Put it back, and it's smooth as silk. With or without the throttle response or the shifting, that in itself is a good gain.

 

As of right now, my throttle is crisp and rpms are rock solid at idle. Zero fluctuation. So, until it becomes even the slightest bit erratic, then I'll try this out.

 

Got this from white_lightning ( Diablo CMR Tuner ) :

explanation of better shifting:
better/cleaner throttle signal will effect shifting because throttle position is one of the columns in the shift tables. PCM & TCM work together.

also, if you look for continuity from TB to ground, there is NONE. tried it with my ohm meter on my truck. casting itself has good continuity, but touch one lead to TB and one to firewall or (-) battery post, and nothing.

makes sense. plastic intake is an insulator.

 

You know it's funny, but my degree is in IS and I hold a bunch of IS related certifications, but I was taught how to work on vehicles by my father (mechanic from his teens till mid-thirties) and my grandfather and uncle who both retired as life-long mechanics. I stopped understanding sh*t when computers went in and carbs/points and the like came out.

I now am at the point where I don't really need to know WHY something works, as long as I can prove that it does...

 

Yes Hammer i agree with you, sometimes when something works and u try to figure out how it works u get a headache ,,,,

 

Alright it's been a week (completely stock 05 Hemi with flowmaster).......only thing I noticed with the throttle body ground hooked up is my overhead mileage gauge went from constant 13.9 to 13.4. Not impressed. I'm contemplating removing it for a week to see if my mileage goes back up. Even did a vid with ground hooked up, and removed.

 

You may not need it, it may be that your TB is ground better than many. With mine, as I've stated, my idle was always erratic as hell and grounding it steadied it completely. I've not noticed any MPG gain, but I've not lost any either (and really can't see how running a ground is gonna LOSE gas mileage). Unlike a lot of guys, I am not seeing any significant difference in throttle response, but I do feel a slightly firmer response.
I've done a few stereo upgrades in like trucks (same year/model/etc.) and have seen most be fine with the cheezy little ground wire, some whined and needed a larger ground wire or needed to be grounded to a better spot. Why? dunno. I can only surmise that some chassis behind the dash were grounded at the factory better than others.

All I can say is if someone has an unsteady idle or has that common stall at red light syndrome, those people NEED to try this simple mod. Because it has almost no cost or time involved I'd encourage everyone with a fly-by-wire try it. If it makes no difference, remove it, but at this point I think it's one that should be tried...

 

I'm thinking my loss in MPG is due to me driving differently trying to see if I notice any benefit to the ground wire. Random throttle burps checking for improved response, and a few WOT runs. I'm just going to leave it on because it doesn't affect anything, and try to keep my foot out of it...maybe it'll come back up.

 

Yes Hammer It seems that this grounding wire depends on truck's TB factory grounding wire condition if it became weak or bad due to a lot of factors, in this case bolting this additional wire improves the Throttle response and shifting (not huge improvement but u can feel it) and some cases the idle, on some trucks it didn't improve anything , But there is no harm in keeping it on as a backup TB grounding wire.
On other dodge forums i saw a lot of Ram and charger R/T owners have had good results from this mod.