Aight guys just need some help doing a big 3 upgrade in a 06 bmw 325I (e90). Just wondering what's the best way to do this or if anyone ever done this with the stock battery in the trunk.....

Ps. What's the best binding post to wire 8 gauge wire in a sub enclosure

Edited February 18, 201114 yr by mikeyraw215

The best way I would think would be to ground the stock battery in the back, then in the engine bay.. ground the engine block to the chassis, then run a line from the alt. to the back positive post on the battery.

For connectors, you could do it two way, either run the wires straight through OR use bolts.

The best way I would think would be to ground the stock battery in the back, then in the engine bay.. ground the engine block to the chassis, then run a line from the alt. to the back positive post on the battery.

For connectors, you could do it two way, either run the wires straight through OR use bolts.

Sounds good, I'll do that. Also I wanna avoid running the wire straight out the box so what's the best bolt set up to run 8 gauge speaker wires. I've seen people using binding post with ring terminals.

Not sure on an 06, what size wire runs from the trunk batt to the jump posts underhood?

Not sure on an 06, what size wire runs from the trunk batt to the jump posts underhood?

Looks like it could be a 4 gauge wire