The first thing we do when we get a new L300 is drive it for a while to discover the issues that we will be working with at hands. We will eventually go over all the stages of upgrades or repairs you can do but for this guide we will explain our standard set of modifications and parts to get a turbo diesel L300 running cooler, faster, and with tuning parameters designed for safety and reliability. The tuning list will be written to assume that your engine is in a somewhat decent shape at least and not suffering from problems like major oil leaks, or blown head gaskets, bad turbo, fuel delivery, etc as this is not a repair guide. All major issues should be addressed first before going about upgrading to try and solve it.
RADIATOR AND THERMOSTAT
The first thing we focus on, is the water temperatures, as our radiators have become somewhat famous in the Delica community you might understand why. Many people not used to the tuning of a small diesel engine and being misled by tuners of larger engines might have been fed advice that alarms them but not understand why, such as EGT's. The first step in bringing down your engine temperature, and all the temperatures associated with it is by bringing down your water temperature. With a low water temp you will see improvements across the board in other temps. We start this process with our aluminum radiator and lower temp actuating thermostat. Many old radiators are often in bad shape, half filled with debris, as well as just too small for the type of driving you want to be doing in your van. The lower temp thermostat, some of you might be wondering 'Why would I change what the factory put in there, the factory knows best!." Well that might be true 25+ years ago in a much colder climate than you are driving in. So we believe by our tested and proven results that changing the factory JDM (82c/88c in winter package) thermostat greatly helps in reducing the water temps along with the radiator. First off, old thermostats get slow and don't operate at their designed temps which is a problem in itself. Secondly, ours 71c thermostat allows the water to flow freely and quickly through the radiator which is often believed to not be good for cooling but that's a fallacy. So to sum it up our first improvement is simply changing these two items.
The next standard upgrades we go with are the ones to let the engine breath better, as diesel engines are high compression, not being able to move the air quickly is their ticket to blow up land. Allowing air in more freely and out is helping that aspect, the cheapest first stage is by adding a high flow air filter, we offer a urethane Simota drop in replacement filter (you can read more about their great benefits in our store). This is the in section for the airflow if you didn't catch it by now.
The next in the basic tuning package would be the the out section for the previously mentioned airflow benefit, would be a short straight through larger diameter exhaust. This mod gives not only the power and great sound that we all crave but it also reduces engine temps in all regards by allowing the hot air from the turbo to escape more quickly and efficiently. This is good in more than one aspect as it not only gives you the aforementioned benefits buts also gives the engine and especially turbo longer life by reducing strain and heat on it. We recommend the shortest most free flowing option you can get (which from us is the 2.5" side dump (you can find it in our store). We also offer a straight back stock style large diameter exhaust but haven't put it up on the store yet.
The next steps in tuning we will dive deeper into how to optimize the water cooling system and fuel system, explain the small and large changes you can adjust in tuning methods and power upgrades so you can decide if you want to shoot for something such as straight up power or economy and top speed optimization, discus and go into the details of how to fortify your Delica for off-road fun and carnage