Here's what I'm looking at on my cheap used R53:






The previous owner hand made a straight exhaust system with a glasspack muffler. They removed the battery box (by cutting it out) and covered the hole with a piece of sheet metal held down by self-tapping screws and red RTV sealant. The carpet in the back is gone entirely and the battery sits in the trunk in a hand-made box, the top of which is a cardboard shoe box. It's pretty lousy, the battery terminals aren't that well covered and it's way too loud in the cabin between the lack of insulation and glasspack muffler droning a lot. In the picture above I've removed the sheet metal over the missing battery box.

Right now I'm looking to change it over to a setup that's less awful, so I had a couple questions. First, what does the inside of the original battery box look like? Is there some sort of carpeting/insulation? Battery hold-downs? I'm thinking it should be possible to rebuild some kind of box which will slot in and replace the old one, and attach it with screws like the piece of metal that's currently in place.

Second, has anyone tried some of the cheap exhaust systems available online? For example, I was looking at this: mystery ebay exhaust or maybe something similarly cheap. I didn't see any mention of this level of cheapassery in the exhaust thread, so I was wondering if there was anyone out here who can tell me if something like that does the job alright, or if I'll really regret not going for something nicer.

 

About the box...best thing to do, is hit up the local wrecking yard. Pull one from a wrecked car. Next best, a new from from the dealer. just beware of the cost..!
This is what I would do anyway. No half-assed junk.

The eBay exhaust you show is very close to the JCW system with two extra flanges. Though that one only shows two mufflers rather than the more normal three. Their "feedback" seems high enough. The 2.50" diameter to 2.00" diameter are pretty normal sizes. It is made of stainless steel.

In my opinion, the store bought $600 to $1000 systems are WAY over priced..!

Mike

 

I didn't consider taking a junk battery box. It looks like the original is welded in, is there some way to remove it (besides a cutter)?

 

Drill out the spot welds just like yours has been removed.

Where are you located? That’s an easy job to weld back up.

 

Junk -

So, then buy a new one...!

That's MUCH better than hashing one together from flat stock.
Jeeze, it's not rocket science.

Mike

 

You could indeed find a wrecked Mini and drill the box out, but I think it would pretty much be better to have someone fab you a custom one at this point if you really want to put a normal battery in. It's really just a rectangular box with flat edges sitting over the sheet metal of the trunk.


I deleted mine, but welded a plate and went with a Odyssey PC680.




Reason being that the Varex muffler wouldn't really fit otherwise.

 

Or you can order a new one from the dealer as suggested. Item #2 in the diagram and the price is circa 2006, so adjust for the minor (unlike Venezuela ) inflation of 13 years.

 

$388 to end up with a bunch of floor parts just to get the battery box. Maybe I'm cheap, but there's no way in hell you'd be down $400 for some flat steel panels that need three 90 degrees bends, a bottom and some welds.