Originally Posted by
jon3950
I spent a little time to tonight lying under the Defender and contemplating the world and all things heat and exboxes. At the risk of stating the bleeding obvious, here are my thoughts. The problem as I see it is the shape of the transmission tunnel. It's basically a big square box at the end that traps all the heat from the transmission and exhaust. The back of this box is the back of the seat box which blocks any airflow in this area. The top of this box is where the exbox sits. Putting heat shield on the bottom of the exbox will help, but a lot of heat is being absorbed by the back of the seat box. This can then be conducted up to the exbox and because it is sealed it then acts as an oven. The first thing I need to do is wrap the exhaust between the flange and the muffler. I only wrapped up to the flange because I was only thinking about my feet (selfish, I know). Once it gets to the muffler it is behind the seat box so should be ok as its all out in the airstream. Not sure what to do next. The most effective solution would probably be self-adhesive heat shielding stuck to the underside of the transmission tunnel and seat box, so there's no dead airspace behind the shielding. This would be a very complicated job and I don't really like the idea of it sitting under there gathering mud. Maybe just a bit on the back of the seat box might help. Another option would be to shield the seatbox and transmission inside the cabin. This might work but the exbox would have to be insulated from the seatbox - ie no metal to metal contact. I've been eyeing off the Exmoor stuff - a lot of money, but if it does the job it would be worth it. They say the on their website it doesn't fit the 2.2 so need to find out about that. Anyway, some food for thought. I'll wrap the rest of the exhaust up to the muffler on the weekend and see how that goes. I also need to get a more comfortable driveway. I can see I'll be lying on it a lot now. Cheers, Jon
