Just bought a Mazda BT50 GT, looking to do some upgrades, if you have any advice please pass it on.
People have been altering car designs for a wide variety of reasons since before Henry Ford started designing his first T model. In all cases they gained something and lost something. All of them knew what they had gained but only those with a good knowledge of car design both in suspensions and engines/drivetrains knew what they had lost and how to compensate for it.
Using 4wds as examples: Lifting it up for driving on difficult mountain tracks will reduce its street stability, particularly in emergency situations at highway speeds.
Excessive rear end weight combined with stiffer rear springs or air bags while towing a big heavy caravan can easily change the car's handling characteristics from the manufacturer's understeer design to oversteer. That is the last thing you want when towing.
Look that one up on the net. It is easy to find plenty of information, photos and charts listing about ten ways to alter understeer/oversteer.
Excessive weight combined with upgraded suspensions out in the deserts have ruined many holidays due to things like bent chassis, broken axle axle housings or wheel.studs.
It is not weight that has caused this, it is mass (the amount of material in something) its location and the forces imposed on parts of the car when it is suddenly lifted or stopped when it is falling then heaved up again on uneven road surfaces.
I am not saying don't modify your car, that can be a great hobby when it is done properly by somebody with a good knowledge of car design and dynamics. What I suggest you do at this stage is go to a good automotive book shop, not a newsagent, and buy a basic book on car design.
That should help you with the gain and loss problem and enable you to get what you want from your car while keeping it as safe and reliable as possible.
I'm pretty new to 4WD. Looking forward many adventures and a world of knowledge.
