Hello everyone. I’m new to the forums I am also fist time owner of 2003 Frontier 3.3 sc. crew cab LB. I hav Ed ordered the Doug Thorly headers. I want to probably eliminate all thd the cats etc. does anyone make a comple bolt on or weld on header back system. Also will be looking into tune for after the mods. Ali can you guys tell me where is best places private or other , to buy lifts bumpers etc. any private guys making weld you own bumper kits for front to hold winch also. I woul li to pr run 33 inch. Tires thanks in advance. And thank you for your time . Rob
Don't hold your breath looking for a tuner. These older ECM's had to have the chip removed from the circuit board, have a new program installed and then be resoldered to the board. Jim Wolfe Technology used to do it decades ago, but they no longer do it. And I don't know anyone else who does. Aftermarket performance parts also tend to be lacking and when you find them, they are usually expensive. Magnaflow makes a nice performance muffler, but they usually run around $600-$700. You might consider having a custom exhaust shop fabricate you an exhaust system; it'll probably be a whole less headache and a lot cheaper. If you are looking for performance for your VG33ER, the best bang for the buck is an undersized supercharger pulley. The stock pulley is 2.6-inches. A safe upgrade would be to install a 2.4-inch pulley, which would give you a pretty good punch and still keep you within the recommended rev limit for the M62 Eaton supercharger. A 2.3-inch pulley is also available and gives you a little more power, but if you have a lot of miles on your engine and supercharger, I would tend to stick with the 2.4". They also offer a kit with a press-on hub so you can swap different sized pulleys by simply unbolting and bolting your choice of pulley. Pulley Boys used to be the "go-to" for the pulleys and you'll need the tool to remove/install them, as well. Also keep in mind that the more air you are compressing into the cylinder, the hotter the combustion chamber will be. So, you may need to switch to a colder spark plug (NGK heat range "7" will probably work).
While I usually tell people that going to an aftermarket cold air intake on most vehicles will produce minimal gains, if any at all, the VG33ER is an exception. Taking out the Nissan factory air box and all of its resonators on the VG33ER and replacing it with a K&N or aFe CAI system will make a noticeable difference...and make it louder, as will. Otherwise, there really isn't a whole lot more you can do to these engines unless you want to spend "mad money."