trying to run multiple runs of 2/0 in a bmw

[bmwking]

hey all, so i've been sitting on some gp audio 2/0 for a few months now just waiting until i figured out how to run it.  The interior is pretty tight in my 99 528, as in, everything is secured really nicely and all that.  I guess what I'm wondering is, is it safe to run it under the car?  I've done a lot of searching and keep getting conflicting results so I figured I'd ask you pros.  I have a buddy who says to never run power wire outside of the cabin, I trust him, but I also loathe the idea of running it inside.  Thanks for all your help!

[audiofanaticz]

I have 18 runs of 1/0 under my truck with no issues for the past few years, but then again it hasnt moved much since I change the rearend every year it seems.

Me personally would not run any bare copper wire that is not "tinned" outside the vehicle to aid and slow down corrosion once the copper is exposed to outdoor environments such as rain, snow, and worse roads that are now covered in slush due to the massive amounts of salt put down by the city. Just personal preference.
Granted your wire is some what exposed to the elements in your engine bay, however its fairly up high and away from being splashed, and not 6 inches away from the ground.
If you do it make sure the wire is very well secured to the highest point possible under the vehicle and doesnt cross any exhaust, or moving parts. Dont ziptie it to brake or gas lines etc.You will also want a good tight weatherproof grommet where ever the wire comes back into the vehicle.

[bmwking]

Yeah I just worry cause the car is lowered, but I haven't scraped ever so it's not like hellaflush or anything.  I wonder if I could get it in up next to the frame rails, tucked away...

[audiofanaticz]

Your car does not have a traditional frame and is a unibody design.
Though there are plastic shields under the vehicle held on with those plastic rivet like clips, so I would assume that if you took those off and ran the wire along the same path as your rear brake line(s) and or fuel lines you would be alright.

But like I said I wouldnt secure the wire to the brake/fuel lines, and dont run it next to anything that gets hot or moves (ie steering rack, driveshaft, suspension parts, etc) and would find something else to secure the wire too, once done just reinstall the plastic shields.
 

[bmwking]

Yeah that makes good logical sense.  And yeah I know it's unibody, I just meant the bump down rails they put there to simulate a frame.  But in either case, thank you.  You've made me feel more comfortable with the idea and I think that's the route I'll go.  Any good idea of a place for 2/0 grommets?

[audiofanaticz]

If its actual 2/0 welding wire, it should be roughly the same size as typical oversized 1/0 gauge wire made for audio. So I would measure the outside diameter of the cable and see to be sure and compare it to a legit audio brand wire diameter.

Then if its the same size or just maybe a couple mm in difference you should be able to use a traditional grommet like these (I also think stinger makes some as well) https://www.sonicelectronix.com/item_35298_Scosche-WPG0-10.html

[bmwking]

I'll have to measure, but the stuff I have is this: http://gpcaraudio.com/limited-edition-gp-ofhc-2-0-awg-white-50ft/

Thanks for your help bud

[WalledSonic]

We just ran some wire under the vehicle for my buddy's JK Wrangler. Used plastic wire loom thats split down the middle (for protection) and made sure it wasnt the lowest thing at any point. Had to be clever keeping it away from the exhaust manifold but we got it. 

[mmpannekake]

ive ran 3 runs from the engine back to the trunk in and 528i sedan and its no problem, you just run it along the original one under the passenger seat and take it out through the fox with the ecu under the passenger side filter for the ac. 

 here are some picture of the run on page 4/5. its all done in a couple of hours and much better in my opinion on this type of car as it is really flat underneath if you arent running it really close to the exhaust. and i scrape on speedbumps alot so i feel much safer having the wire inside.

there is alot of foam for insulating under the carpet so you just have to cut a groove in it a couple places and the carpet will go flat down and you wont notice that there is anything under there as there will be no bulge in the carpet.