Grounding Kit + Vq35 Intake Mod = Win!

[pixel8r]

Well I've now connected my previous earthing attempt up with the intake and also across to the factory earth on the opposite side of the engine, for what its worth.

This time it does seem to have made a difference. The results are very unscientific, and very much based on "seat of the pants" impressions, but in the last few days I've done >550km and have experienced NO annoying moments like I used to get all the time, especially when driving to work and back. The gearbox is still slower to shift than I'd like, but now it behaves like a normal auto, so its definitely an improvement. No crazy long delay when I put my foot down now.

It doesn't make the car feel faster or anything like that, but I'd have to say it makes the car very consistent in how it drives. No more off days or sluggish drives. It now feels responsive and quick all the time. (well, as quick as any factory M35 - its still relatively quick compared to other wagons)

If I'd paid $200 for this mod I'd feel very ripped off, but since it only cost me $10 or so, I'm pretty happy with it

[andy65b]

OK, post up some pics now.

[pixel8r]

I didn't use the 8guage wire or anything that serious. The guy I spoke to at the auto shop gave me 25amp wire and said that being a ground wire and that its not connected to anything thats likely to carry a huge current, 25A would be plenty. It is suitable for use around the engine though, dont want any heat-related issues.

Its also not the prettiest install you'll ever see but hey, it seems to work and thats the main thing.

Hopefully this makes sense. I've drawn yellow lines to show where I've run the wire and where its connected up to.

The wire from the battery to the engine goes under the intake pipe because its very handy to be able to remove the airbox in order to get better access to headlights etc. so I wanted the wire out of the way. I couldn't be bothered removing the engine cover to take photos cos I've done that enough times over the last few days. Its pretty easy to work out what I've done though. There are 2 factory ground points on the right hand side at the front of the engine, and one on the left of the engine at the front. Its probably not necessary to run a wire between the two areas, the engine is all metal anyway, but I had plenty of wire so I did it anyway.

Here's a pic of the throttle body connection, showing where I ran the wire for that side.

This wire runs under the intake pipe, and hopefully isn't touching anything too hot (its properly insulated anyway, so should be fine).

If anyone can see any problems with this setup, let me know. I'm no expert, I just had a go - it seems like a pretty non-complex thing to do. I've used cable ties to hold the wires in place but black tape is probably a neater solution.

Once again, you may feel that this mod does nothing at all. In my case, the factory earth setup was not fantastic, everything is earthed through the chassis, and there was no direct earth running from battery to engine. If any of the other ground connectors to the chassis were corroded etc, this would have caused problems. Hopefully by earthing a few spots directly to the battery I've improved things a little/lot.

Given that the engine/gearbox performance seemed to be a bit temperamental before, and seems more consistently good now, I'd say its a success, and makes sense from a technical perspective.

[BensDR30]

Personally, I would test the earthing of the vehicle and clean the factory points before purchasing any kind of 'kit'. But I'm not replying to ignite any debate over the matter, but to highlight the coolant issue mentioned earlier.

(When re-wiring my Z, I did completely redo the earth wiring, running large gauge cables between the block & body, with the battery earth only going to the body).

It is quite possible that if the earthing of the engine is poor, then the coolant/radiator can become a substitute path. Further to that, radiators cores have[/] failed well before their time due to the electrical flow, and subsequent corrosion (they basically become a sacrificial anode). This shouldn't occur on any rubber-mounted radiator, however!

food for thought...

[pixel8r]

Personally, I would test the earthing of the vehicle and clean the factory points before purchasing any kind of 'kit'. But I'm not replying to ignite any debate over the matter, but to highlight the coolant issue mentioned earlier.

(When re-wiring my Z, I did completely redo the earth wiring, running large gauge cables between the block & body, with the battery earth only going to the body).

It is quite possible that if the earthing of the engine is poor, then the coolant/radiator can become a substitute path. Further to that, radiators cores have[/] failed well before their time due to the electrical flow, and subsequent corrosion (they basically become a sacrificial anode). This shouldn't occur on any rubber-mounted radiator, however!

food for thought...

I wouldn't be surprised if there is some fault or corrosion or something similar with the factory ground points, that would account for the benefits gained, but how much time do you want to spend troubleshooting that kind of "problem"?

[chad bob]

Theres a very simple way to check if you need to install a grounding kit or not. Get your mitts on a cheap multimeter, put it on the lowest resistance setting (omega symbol for ohms) and put one probe on the battery negative terminal and the other on the intake manifold (furthest part of the motor from the factory earthing strap).

Remember the reading that the multimeter shows (mine said 0.1 OHMS) now connect a decent piece of copper wire, (be it 8gauge amplifier cable or 25amp cable doesnt matter) between a bolt on the intake and the battery negative terminal. Now re test the resistance with the multimeter, mine came back with 0.02 OHMS after installing the grounding wire.

This means that the factory earth is utter BS or has been damaged, check it out on your car before doing an earthing mod if you must. VQ engines are renound for poor earthing strap design.

I did the same mod on my 2L track car (not a NISSAN) and the resistance went from 0.6 down to 0.04 ohms, should give a nice strong spark now.

[BensDR30]

I measured the resistance between 2 equipment racks in our computer room a couple of years ago, and there was nearly 5 Ohms between them - this highlighted an earthing issue with the building wiring. This equated to a good couple of Volts, which is unacceptable when you're talking about signalling...