Grounding the throttle body to improve response.

Status
Not open for further replies.
Joined
Jan 17, 2006
Messages
849
Location
WA
I've read a few threads recently on various Mazda forums/boards about improving throttle response in Mazda 2.3l & 2.5l engines by grounding the throttle body. The results people report run the gamut from incredible to snake oil, which is naturally off-putting to someone like myself who isn't really into modding my cars (especially a Mazda5). That said, it seems like the $5 for a battery cable (or 8g wire and ring connectors) and the couple minutes it would take to do this warrants an experiment.

So, does the idea of grounding the throttle body to increase throttle response have some sort of legitimate merit? Or is it a "ricer" placebo effect? Mind you, I'm not looking for incredible results; rather, anything that helps w/throttle lag in these drive-by-wire A/T's would be awesome.

Also, any negatives associated w/doing this (if it indeed works)?

Appreciate any comments!

M_C
 
I don't see any sensors being grounded to the TB so I'm not really buying it.

There MIGHT be a sensor in the intake manifold that sees a better ground through a TB mounting bolt, if you attach the ring there. But most computer sensors have an independent ground back to the ECM.

Maybe the theory is the TBW motors are current limited by the wiring to them?
 
You don't need a battery cable. Nothing on the throttle body requires that many amps. You could use 10, 12, or 14 gauge wire, but as mentioned above, it sounds like snake oil.
 
Thanks for the quick replies, Guys.

Here's a bit I snipped from a post that, compared to some of the other thing's I've read, is a bit more "eloquent" in it's summation:

I think I may have the explanation for the grounding that makes the engine feels more responsive. Throttle, or the "pedal" is basically a potentiometer that's connected to a voltage source that varies the input voltage on the input of one of the pin(s) on the ECU. It may be that the actual mechanism that controls the air/fuel mixture is sharing the same grounding point that's limited at which case, may be introducing a sort of parasitic reistance of its own. Now, as the resistance on the pedal/potentiometer varies, input voltage will vary accordingly. However, because there's a finite amount of resistance on the grounding wire side, it may be introducing a variable voltage drop of its own. Now, think about it, when it does that, ECU with lower than expected voltage at any given time which may explain why further travel or higher resistance is needed to get the result one was expecting, i.e. I've noticed this on a hill when I needed more HP but the gear would not kick down until I press it almost to the floor, then the engine sounds like it reving out of control, and at times, too much rev and torque results giving the driver less control.

Adding a less resistant ground of the throttle body may just be the trick into getting rid of that parasitic resistance at which case, now the ECU may be sensing a better input voltage.


As I noted earlier, I really don't know anything about drive-by-wire systems and how grounding the throttle body (either to the battery or to a common ground) would decrease throttle lag. That's why I come to the good people of BITOG...

M_C
 
as far along a TBW has come i would think a kink like this would have already been overcome or corrected or accounted for, now if this is a mod for a early TBW system, maybee..
 
The throttle body should be grounded already by the connector that plugs in to throttle plate motor. Anyway, I did this a couple years ago to my Mazda3 because I had wire and ring connectors in the garage already. I did not feel a difference. Also, 8g wire is waay overkill for something like this. I used like 12g or 16g.
 
Last edited:
Originally Posted By: Mustang_Cougar
I've read a few threads recently on various Mazda forums/boards about improving throttle response in Mazda 2.3l & 2.5l engines by grounding the throttle body.

Have you tried connecting a multimeter (set to ohms) between the throttle body and the car's body?

If you get continuity between the throttle body and the car's body, then the throttle body is already grounded, from the factory; no additional grounding will have any effect of any kind.

Also, have you considered the relative speeds of electricity and your foot? Electricity moves at the speed of light. Does your foot move even close to that speed?
 
For what it's worth, on my truck, I ran a ground cable to one of the bolts on the throttle body along with a few other locations under the hood when I was grounding it and noticed a significant difference.

I have no way to verify this, but, my thought on grounding is the more up to date a vehicle is, chances are the better grounded it is since automobile manufacturers have had ample time over the years to work out the kinks with the electronics. My truck, which is an older model, had horrible factory grounds.
 
Unless there's definitive proof that the throttle body sensors or in the case of DBW (drive-by-wire)motor grounds to the metal throttle body, otherwise, there shouldn't be any need for additional grounding.

While I don't dispute the benefits of an extremely low resistance grounding between the chassis and /or the alternator and the battery negative post. I do, however, critically aware of the improperly added additional grounding causing ground loops, which will definitely makes things worse.

Ever heard of ground loop in electronics sense? Google it if you like to know.

*ground loop may cause additional mis-behaviour to the ECU inputs due to introduction of unnecessary "stray" noise to various sensors*

Q.
 
These kind of internetz rumors occur in car forums all the time.

Unless the OP posting had a problem with the factory grounds to sensors that control the tb electronics it will make NO difference.
 
If the factory grounds are poor, it might have a difference. 8 gauge wire is massive overkill, though. 16 gauge is more than plenty.
 
You should notice no difference at all, the Mazda 5 minivan should have ample response on par with any other micro van of this era. I would suggest getting rid of any extra weight and using a top tier gas, that should bring back that zoom zoom you were promised in the show room.
 
While I have seen so called 'hypergrounding' yield results on some cars it is unlikely to do much.

You would be much better served by locating the fuse to the adaptives and removing it to reset them if possible. Most cars these days are trying to figure out your driving patterns and adjust things like throttle response and shift points accordingly.

You can also buy boosters to accelerate the ramp rate.
 
the jeep forum i'm on has one fellow that stumbled across it and was surprised to feel a difference. our intake manifolds are plastic, so the tps sensor and TB motor either have independent grounds or a single connection. I think a couple others have tried it and said they also noticed small differences.

I intend to at some point just to see.

Even if a no-load resistance reading shows negligable resistance, it may be different with the vehicle running with the alt dumping 30A from frame to chassis.

I had to track down flickering power in a minivan years back and metered all kinds of voltage loss from alt frame, through engine, to chassis, to battery. over a full volt in what should be a high-current path. I made a multi-lug ground strap that tied all of the above together, plus the BCM and the ECU. The flickering didn't stop one bit!! (a new battery did) HOWEVER, that transmission came alive and shifted with more precision than I had ever known! It was uncanny, the difference it made.

WRT ground augmentation, I won't make fun of it, as I've seen it help *some* cars. My accord never needed it...

M
 
Thanks for the replies everyone.

BTW Buick92: I'm really intrigued by what you've done to your new Corolla (ie, installing a cold air intake, going NOS and adding that high-performance chip), so please keep me updated about your performance gains.

M_C
 
The technical approach is to use a sensitive DWM to measure the drop, as others have suggested. One lead on the battery minus, one on the throttle body itself. If there is resistance in the ground circuit it will show as a voltage, probably millivolts. Add a temporary ground and measure again. The lowest resistance grounds are those which terminate right at the battery terminal. You can use the same approach to look for a drop in a headlight circuit, for example, in that case with the lights on you put one lead on the headlight connector and the other on battery plus. You ca read the drop. You can also read any drop in the ground side the same way. One lead on the grounded headlight terminal and the other on the battery minus. You have to look at the entire circuit path to get an accurate assessment.
 
One source of confustion to the "layman" is "the conventional current flow theory". The + sign on a battery terminal does NOT mean "there is a surplus of electrons here"
it means it "attracts electrons" from the minus (-) terminal. So, current flow in a negative ground car is FROM the negative terminal, through the negative lead, through the body, into the device being powered, OUT of the device and back to the + terminal of the battery through the harness. I agree that for the layman, reversing the terminal labels would make more sense, but it is what it is and has been so since the first electron tubes were made. Heat boils electrons OFf the cathode of a tube (the -) which flow TO the "plate" which is connected to the + side of the power supply. Must of been a shock to the early guys when they discovered they had the signs backwards.
For filament bulbs and heating elements the flow direction makes no difference, but for motors and electronics (and LED bulbs) it does. The better "wedge socket" led bulbs today have a diode circuit built into the base which ensures the polarity to the LED element itself is always correct. Led bulbs which don't have that circuit only work one way. Didn't "useta" matter with filament bulbs.
Since I have 2 100 watt output radios trunk mounted in my vehicle, I ran a number 8 wire from the mounting rack back to the battery minus. Eliminated about a volt of loss that way. Car sudio suppliers have lots of good quality terminals - including battery terminals to pick from since high power audio amps (whatever you think of the music) require a low resistance circuit to work properly. A good source for hardware. BTw, the electronic symbol for a soid state diode ( a one way gate) is BACKWARDS from the actual current flow. What looks like an arrow is actually a symbol for a pointed contact within the early diodes. No wonder the average guy gets confused.
 
Last edited:
I tried it on my Mazda3. It made absolutely no difference. The throttle is laggy regardless and it's especially obvious during rev-matched downshifts, just like with every other electronic throttle I've tried. It's the emissions programming, not a simple grounding issue. You need to find a programmer.
 
Status
Not open for further replies.
Back
Top