battery relocation help

[eg2]

I'm helping a mate prep an S14a for some track racing, and we'd like to relocate the battery to the boot.

We are opting for 35mm/Sq cable to minimise voltage group over what we estimate to be a 4m run of cable.

I'm under the impression it's good practice to fuse both ends of this cable, and that I should fuse it for what the cable can take, which is 240A, but I can't find a 240A fuse...

Should I calculate the draw from the starter and fuse it a little above that? Should I fuse it at all?

I'm not great with this stuff so any advice and/or pointers to places I can buy what I need would be appreciated...

[stealthstylz]

Any reason for going to the boot? Usually lower and better for weight distribution to stick it behind the passenger seat.

[eg2]

He's adamant he wants it in the boot, I've suggested in pass footwear or behind pass seat, but he said no, and it's his car!

[dodgerover]

Needs to be fused for just over the maximum the starter will draw (with a tight engine when the oil is cold and thick in winter) if you are going to fuse it at the battery end. You could probably just be sensible about the routing and use plenty of rubber lined mounts along with grommets where ever it passes through a bulkhead and be fine without fusing. Plenty of mercs run the battery in the boot and I don't remember noticing any fusible links on the main connections.

No point fusing at the max rating of the cable as the fuse is supposed to be the weakest link that will go before damage is caused to the cabling etc.

[Deleted]

The weight of a battery would make absolutely no difference to weight distribution unless you are running a proper full on race car where 1/100th of second is the difference between winning or losing.

[slater]

I dunno if your running a big battery its useful ballast to shift. My battery weighs 900g and i still worry where to put it!

[dodgerover]

Probably handy thing to shift if you needed to balance up corner weights with the driver seated? Anyway how is the relocation going?

[stealthstylz]

Feb 8, 2015 18:01:52 GMT @1300dolly said:

The weight of a battery would make absolutely no difference to weight distribution unless you are running a proper full on race car where 1/100th of second is the difference between winning or losing.

Any ballast you can get on the passenger side is worth doing, plus its cheaper to do it properly.

[eg2]

ok had another chat with him about it today, the reason he wants it out of the engine bay is the shortest route for the intercooler piping is through where the battery tray is. he'd prefer not to have it in the cabin as if his daily packs in he's like to be able to throw in the original interior and use it on the road so he can still take his little girl to nursery (important to him as he's a single dad) and get to work...

dodgerover, its not going too badly thanks chap, I've run the main cable and made the earths for both ends, plumped for a 200A breaker in the end - waiting for that to turn up and I'm building a custom box to sit it in in the boot... not all that difficult to do to be honest. I've moved it to the passenger side though to aid weight distribution incase he decides to get the corner weighting done

[benjy_b]

When I had my 200sx I found it best practice to fit a smaller battery of a similar amperage and turn it sideways in the battery tray.

From what I can remember, the battery was from a Mitsubishi Lancer Evolution.

Saves messing around running cabling through the car and fabricating a mount for the battery elsewhere.