Dual batteries 1994 4runner 2.8 diesel

Werner, I had the option of heading down the same track as Paul did. My only problem was time and money. I may still look into a similar setup. I also have a Finer Filter air filter and this takes up a significant amount of space. One option I have is to replace this with a custom unit to fit the space available. I may look into this one day, but for the time being, had to settle for the battery in the tray. cheers, Sam.

Paul, sounds like you've gone down the path which I am about to go. I also was going to put a snorkel on the inlet. I am going to have another play with the filter tonight and the car is going to my mechanic on Fri for a service as well as a look into the dual battery situation. Will keep you posted as to how I go. Thanks for the replies Paul and Sam.

Hi Paul, having reread your reply, it seems as though our engine layouts may be different although we have the same size engine. On my vehicle the air intake is currently on the passenger side next to the headlight with the air filter sitting directly behind the headlight, its axis running in an east-west direction. The main driving battery sits directly behind the driver side headlight. The intake manifold for the engine is located on the passenger side. Could you please clarify your setup ?

Regards, Werner

Werner, as you correctly pointed out, my original set-up is as per your description i.e. air filter housing (cylindrical pressed steel unit) running east west directly behind the passenger head light and the main battery on the opposite side, behind the driver's headlight.
I then moved the steel air filter housing into a north south axis, parrallel with the engine and close to the firewall. This is where the difficulty comes into the modification. Both the air inlet and outlet pipes were cut, repositioned and welded in place. The air inlet pipe was measured, cut and shortened so as to line up directly with the snorkel connection which comes through the body and into the engine compartment above the leaft front wheel. The air hose supplied with the snorkel kit connects straight onto the new air inlet pipe (no extra bends, etc required).
The air filter housing discharge pipe was also modified so as to line up almost directly with the original intake manifold arrangement. The existing rubber pipe which connects the existing air filter housing and the manifold was cut shorter (~20cm total length) and now connects the two perfectly.
Underneath the original air filter housing is a flat plate already spotwelded onto the body for a second battery position. I welded up a larger frame and positioned this ontop of this plate with the battery now sitting very close to the radiator top up water bottle. This top up bottle is secured with a 8mm bolt to the grill cross member and slightly to the left of this 8mm bolt is a threaded bolt hole which I've used to secure a battery bracket.
The complete system now consists of a second battery positioned east west directly behind the headlight, the air filter housing positioned north south between the engine and body panel (wheel panel) with the rear of the housing close to the fuel filter which is positioned on the firewall.
To access the air filter element the second battery must be removed so that the three clips and double cover can be removed.
Werner it probably sounds complicated but once I got the measurements and alignment done it was pretty straight forward. It's now a pretty compact arrangement with the added bonus of not loosing any space in the well body where most auxillary batteries are fitted as well as not having to run long battery cables between the two units.

Thanks very much Paul for the detailed reply. I will pass it on to my mechanic. Werner