Here is a performance parts mod list I have been working on, its not finished as I am always doing research so more will be added as time goes on. Here is what is available, what should be available and what can be made at home and so on…
Intake:
1a) DYI Intake Mod – Removal of (3) Resonators and adding a K&N Filter
1b) Short Ram Intake Kits - K&N, Volant, Nismo, Airaid, AEM, and Generic/eBay
1c) Snorkel - 4x4parts.com – The only real CAI for the Xterra, works with the factory air box and the Volant intake kit.
2) Throttle Body Spacer - Poweraid and Generic/eBay - Still a debate on possible gains.
3) Bored Out Throttle Body - SLR was the only company producing these. Is there any machinist on this forum, I would pay to get my TB bored out and a larger throttle plate.
4) Intake Manifold Spacer Kit - Yet to be produced because no one will sign the petition at the top of this page! According to testing these provide a decent amount of hp/tq for the cost.
5) Intake Coolant Bypass - Either a kit off eBay or a DYI kit, this mod should cost less than $10 and is NOT recommended for colder climates.
6) EGR Delete - Only a select few of us even have them, I’m not sure if it has even been done or can be done in the Xterra world. Further research must be done.
Exhaust:
1) Headers - 4x4parts.com - These delete the main cats and O2 sensor relocation required.
2) Federal Down Tubes - Walker Exhaust – These delete the second cats, if you use these with headers you must add a catalytic converter somewhere or use O2 sensor simulator.
3) High Flow Cats - Magnaflow is my personal brand of choice, you can get them fairly cheap off eBay.
4) Muffler - Anything is better than that trash can sized thing that Nissan calls a muffler, the Nismo Cat-Back system seems to be a hot item right now as you can get it for around $300 shipped off eBay and it comes with a new Y-pipe, if your interested buy one while you can because the guy only has a limited number on hand and when they are gone they are GONE.
5) Resonator – There is no point to adding one, there is no point for the one that is there to begin with. Get rid of it you dont need it, its the small can right before the exhaust tip
6) Piping - Mandrel bent has the highest flow ratings because it is no crushed but is also the most expensive and somewhat hard to find a company that does it, as for what size piping this seems to be a good rule of thumb..
http://www.angelfire.com/my/fan/Exhaust_Pipe_Size.htm
Cooling
1) Electric Fan Conversion - I am going with a 16” Zirgo fan from eBay, what this will do it help take some stress off the engine, the engine turn the fan currently so with an electric fan the engine will be able to rev more freely, Yes the water pump is attached to the same pulley but IMO it will still have some impact. I will hopefully be doing a write up for this in a few weeks.
2) Thermostat – Personally I like the Nismo Thermostat, its quite expensive but the Nismo thermostat open at 143 degrees and the standard opens at 170 degrees. This will allow your radiator to start cooling your engine before the temperature gets too high. Cooling running temperature will yield higher power and throttle response. Also this will mean less work for your new electric fan.
Other
1) Automatic Transmission Cooler – Keep your automatic transmission fluid cooler giving you better gas mileage and longer transmission life. Also because of the reduced heat less power is lost though the drive train.
2) Synthetic Upgrade/Conversion – Upgrade all your fluids to full synthetic AMSOIL. Everyone knows the benefits of running full synthetic oils, I don’t condone just draining out everything, if it needs to be changed then convert it. And keep in mind everything, The differentials, transfer case, transmission, engine oil, even power steering if you would like. There are also coolant additives that you can add to enhance your cooling, such as a product called “Redline:Water Wetter”
3) Computer Upgrade – If you send 4x4parts.com your computer they will tune the ECU to get the most out of the performance mods that you have. The cost is around $325 and you are required to send in your computer so there will be some down time until you get it back.
4) Cam Upgrade – 4x4parts.com offers 2 kinds of cams for the VG33E a high performance and a race cam, I do not recommend the Race cam as I think it will be too much for a daily driver, it may work well as a trail only rig but I would still lean more towards the high performance version. Along with a new cam, new lifters are required as well.
Intake:
1a) DYI Intake Mod – Removal of (3) Resonators and adding a K&N Filter
1b) Short Ram Intake Kits - K&N, Volant, Nismo, Airaid, AEM, and Generic/eBay
1c) Snorkel - 4x4parts.com – The only real CAI for the Xterra, works with the factory air box and the Volant intake kit.
2) Throttle Body Spacer - Poweraid and Generic/eBay - Still a debate on possible gains.
3) Bored Out Throttle Body - SLR was the only company producing these. Is there any machinist on this forum, I would pay to get my TB bored out and a larger throttle plate.
4) Intake Manifold Spacer Kit - Yet to be produced because no one will sign the petition at the top of this page! According to testing these provide a decent amount of hp/tq for the cost.
5) Intake Coolant Bypass - Either a kit off eBay or a DYI kit, this mod should cost less than $10 and is NOT recommended for colder climates.
6) EGR Delete - Only a select few of us even have them, I’m not sure if it has even been done or can be done in the Xterra world. Further research must be done.
Exhaust:
1) Headers - 4x4parts.com - These delete the main cats and O2 sensor relocation required.
2) Federal Down Tubes - Walker Exhaust – These delete the second cats, if you use these with headers you must add a catalytic converter somewhere or use O2 sensor simulator.
3) High Flow Cats - Magnaflow is my personal brand of choice, you can get them fairly cheap off eBay.
4) Muffler - Anything is better than that trash can sized thing that Nissan calls a muffler, the Nismo Cat-Back system seems to be a hot item right now as you can get it for around $300 shipped off eBay and it comes with a new Y-pipe, if your interested buy one while you can because the guy only has a limited number on hand and when they are gone they are GONE.
5) Resonator – There is no point to adding one, there is no point for the one that is there to begin with. Get rid of it you dont need it, its the small can right before the exhaust tip
6) Piping - Mandrel bent has the highest flow ratings because it is no crushed but is also the most expensive and somewhat hard to find a company that does it, as for what size piping this seems to be a good rule of thumb..
http://www.angelfire.com/my/fan/Exhaust_Pipe_Size.htm
Cooling
1) Electric Fan Conversion - I am going with a 16” Zirgo fan from eBay, what this will do it help take some stress off the engine, the engine turn the fan currently so with an electric fan the engine will be able to rev more freely, Yes the water pump is attached to the same pulley but IMO it will still have some impact. I will hopefully be doing a write up for this in a few weeks.
2) Thermostat – Personally I like the Nismo Thermostat, its quite expensive but the Nismo thermostat open at 143 degrees and the standard opens at 170 degrees. This will allow your radiator to start cooling your engine before the temperature gets too high. Cooling running temperature will yield higher power and throttle response. Also this will mean less work for your new electric fan.
Other
1) Automatic Transmission Cooler – Keep your automatic transmission fluid cooler giving you better gas mileage and longer transmission life. Also because of the reduced heat less power is lost though the drive train.
2) Synthetic Upgrade/Conversion – Upgrade all your fluids to full synthetic AMSOIL. Everyone knows the benefits of running full synthetic oils, I don’t condone just draining out everything, if it needs to be changed then convert it. And keep in mind everything, The differentials, transfer case, transmission, engine oil, even power steering if you would like. There are also coolant additives that you can add to enhance your cooling, such as a product called “Redline:Water Wetter”
3) Computer Upgrade – If you send 4x4parts.com your computer they will tune the ECU to get the most out of the performance mods that you have. The cost is around $325 and you are required to send in your computer so there will be some down time until you get it back.
4) Cam Upgrade – 4x4parts.com offers 2 kinds of cams for the VG33E a high performance and a race cam, I do not recommend the Race cam as I think it will be too much for a daily driver, it may work well as a trail only rig but I would still lean more towards the high performance version. Along with a new cam, new lifters are required as well.