Battery relocation to boot (trunk)

[GTD.]

I need to relocate my battery to the boot (trunk) on my MK2 (A2) Golf GTD so I can fit my intercooler pipework.

I've found a box that can take my heavy duty diesel battery of a 9n Polo TDI, it has a fuse panel with M8 studs built in, perfect for running all the wires needed to the front, I also have a large reel of black 6 AWG CSA-TEW 105°C AWM 1283 105°C 600V VW-1 BS6231 16.0MM² rated cable will this be sutable for running to the starter? or will I need to run two cables?

I plan to rewire the starter, alt, fusebox and VDO 60amp ammeter with the AWG6 wire, mostly with soldered on M8 connectors but with M6 at the ammeter and M10 at the starter and alternator..

Also where is best to earth the battery in the boot (trunk), I plan to earth in the boot(trunk), and run a cable to the block earth and ath the front chassis battery earth and link them all together.

With the cable bieng black I plan to use red heatshrink in the ends to show which ones are +ve connections.

Cheers
Simon

[Northern RD]

Somebody at the Vortex sight was talking about that not long ago and he mentioned that he got the best results for a good ground by using the big bolts that anchor the seatbelts.
N.  

[QuickTD]

6 guage is nowhere near large enough for the starter, especially if the battery is in the trunk. 6 guage wire is good for about 60 amps continuous maybe, 200 amps intermittant. You would need at least 4 parallel runs to feed the starter, it will draw about 500-800amps. I would use a single large cable, a minimum of 1 guage, preferably 1/0 at that distance. You could ground the battery in the trunk, but I wouldn't. Body sheet metal makes a very unreliable conductor. It would be better to run another 1 or 1/0 cable back to the engine block and bring all the grounds together at that point, hub and spokes style. Single point grounding is good electrical practice. The 6 guage should be adequate for the alternator and fusebox  wiring.

[GTD.]

I've found a couple of BMW 3 series with boot mounted batterys and really thick battery to starter cables, a 92 325i and a recent 3 series, the 92 has black +ve to starter cable, and the later one has red cable from battery to starter, so I'm going to use the black one for ground.

[veeman]

FWIW, the older style "big" Audi's (5000, 100, 200) have their batteries in the rear as well.  For my rabbit, I grabbed the entire cable from a 5000 in the yard and used that for the positive cable.  

The Audi cable goes along the passenger side and has a factory splice right at the firewall.  You'll have to wrap that with some insulation or simply cut it to the length you need.

Those cars even have a neat positive terminal "stand off lug" on the front frame rail that can be used as a power junction for accessories after the swap.  

Hope that helps...