#1) The tune of your choice from Green Diesel Engineering.
#1A) If you get the GDE tune, an upgrade to the torque converter is highly recommended. Either a Suncoast converter or the European Spec torque converter will do. If you are going to get the GDE Hot Tune or the replacement turbo kit, you may be further ahead in rebuilding the entire transmission with an upgrade kit. I do not know for sure myself, but some people are recommending the following company for a stage II or stage III 545RFE transmission, which is the automatic that is in your CRD...
SharaDon Performance Website:
Home - SharaDon Performance
#2) My thermostat... the Hot Diesel Solutions Model 001. You simply are not getting all of the efficiency, power and reliability the engine is capable of if the engine is not running hot enough.
#3) If you are in a cold climate, install an engine pre-heater like a Webasto TSL-17. Mount it into an aftermarket front bumper like the one from ARB. The TSL-17 is designed to warm up commercial engines up to 15 Litres of capacity, so it is going to have no problem with the little 2.8L 4 cylinder in the CRD. It is thermostatically controlled so it will not overheat your engine, and I believe it will heat to about 170 degrees Fahrenheit. This is an expensive mod, but well worth it because you will NEVER have to idle your engine to warm it up again. It is never a good idea anyway for a diesel engine to idle for warm-up unless you can control your idle speed as the idling simply fouls up your engine oil. With a TSL-17 properly installed and fired up, your CRD will start like it was in the heat of summer even if it is -40 degrees outside.
#4) If you decide on the Webasto, you will have to drop the fuel tank to install the diesel fuel suction line. You should also put in a lift pump at the same time for positive fuel pressure to your fuel filter head.
#5) Custom stainless steel exhaust, from the turbo back.
#6) DO NOT BLOCK OFF THE EGR... THE GREEN DIESEL ENGINEERING TUNES SHUT DOWN THE POLLUTION CONTROL SYSTEM THROUGH THE COMPUTER, SO BLOCKING OFF THE EGR IS UNNECESSARY, AND CAN CAUSE DAMAGE TO THE TURBOCHARGER IF SURGING OCCURS. Keith at GDE discovered a program in the ECU that briefly opens the EGR during driving conditions that can cause turbocharger surge, relieving the intake of excess pressure. YOU SHOULD KEEP THIS FUNCTION TO PROTECT YOUR TURBO. Admittedly, this condition is rare, but why take the chance if the EGR is shut down most of the time anyway? Turbo surge can destroy a turbo if it is not dealt with properly. Turbo surge is more frequent the higher the boost pressure of the turbo, so turbo surge is even more prevalent if you decide to go with the replacement turbo kit from GDE.