This focuses on providing more detail to the common mod upgrades found on most N2x cars and what to look for when selecting an upgraded part. Please note this will not cover big turbo's and forged motors.
- Whilst most people may not find a direct benefit with running an upgraded intake on stage one tunes, you will see these become beneficial as you go up the "Mod Tree". The stock intake is prone to cracking and the Nylon material does an excellent job at absorbing the heat from both the engine and the radiator fan and as mentioned before this helps cause the intake to eventually crack. Ultimately the route the intake takes on the N20 is a poor choice as the hot air from the radiator blasts directly onto the intake tubing.
Choosing to use an upgraded intake not only allows you to use materials less prone to early/premature heat soak and cracking/damage but also allows you to feed more air into your turbo especially when running upgraded turbos. The other direct benefit most people will enjoy is the increased intake sound as the stock intake has a resonator to effectively remove the diverter sound and sound of air drawing into the engine under load.
- Known Upgraded Intakes that are just work.
Upgraded Turbo Inlets:
- Turbo inlets are one of the most common units to fail due to their plastic designs, they are also quite an air restriction to upgraded turbos on the N2x Platform, it is recommended to upgrade it as cracks/failure on these parts are often hard to find at first glance without completely removing the part. Failed inlets can also cause issues with the car stalling or wanting to stall on start-up, or triggering CEL Codes like mixture too rich or too lean or airmass too high.
A failed inlet also allows air to enter the induction system or "engine" without filtering which can allow FOD (Foreign Object Damage) to occur.
It would be best to recommend to get an inlet that is a solid piece preferably made of some sort of metal over plastic/silicone-hose as they're more robust and minimise the amount of connection points into the inlet which can increase the risk of leaks occurring in the future.
- When choosing an upgraded intercooler, typically "Bigger is always better" whilst there can be arguments made for "increased turbo lag on smaller turbos/stock" on the stock turbo intercoolers up to 7.5 - 8.5 inch in "height" have minimal affect to boost response/lag on these motors, and are still preferred as it helps reduce overall intake air temperatures. Another consideration you need to make is whether or not the intercooler will fit your bumper, those that have the "Sport/Luxury" front bumpers whilst most can fit the largest "Off the shelf" intercoolers, they will have issues getting fresh cool air into the intercooler due to reduced intercooler air inlet in the bumper. The suggestion here would be to ensure you upgrade to a "M-Sport" bumper first before going for the largest height intercooler, if you have no plans to upgrade your "Sport/Luxury" front bumper, then save some cash and opt for a more reasonable 5-5.5 inch intercooler since that way you would be maximising the available/exposed surface area available to the intercooler and would be getting the best value for money.
- Back to "Bigger is always better" If you can afford to, and you have or will have a "M-Sport" front bumper, then my suggestion is to go with something around 6inch - 9inch in size, an example would be like the "VRSF Race 6 inch" or "Mishimoto Performance Intercooler (comes in around 8.5-8.7inch high)" which are good examples of both the "minimum and maximum" size in N20 performance intercoolers. When it comes to construction of the intercooler, "Bar and Plate" is usually favoured as they are more durable for FMIC applications.
- When choosing an upgraded charge-pipe, it is important to take into consideration the design and its features, generally having a few meth bungs opens up your opportunities to maintain use of the same charge-pipe as you upgrade the rest of your engine setup etc. Whilst upgrading charge-pipes is usually a pretty straight forward process with no real problematic units out there, it is advised to also install upgraded hose clamps on a charge-pipe kit you buy as most of them ship with cheap clamps that can blow off under boost.
- The main reason these are upgraded is due to the weakness of the stock plastic/silicon charge-pipe system these are known to crack under high boost and various heat cycles.
Upgraded Diverter Valve/BOV:
- One of the most important parts of your boosted setup is the ability to have excess boost pressure released from the charge air system. The stock unit whilst effective is prone to breaking due to its plastic construction, it also hurts performance of the system under high boost as the electronic actuation of the device means it opens and closes venting usually too much boost and forcing the turbo to rebuild boost at higher RPM.
- Generally whilst most of the N20 upgraded DV's (Diverter Valve) out there are a good choice, the most cost effective and mostly reliable product has been the GFB DV+ its also the most headache free from a electronics point of view. Despite the horrible pain it is to install an upgraded DV of an sort or even to service the stock one, we still recommend getting it upgraded as it will help the overall response and dependability of the turbocharged system on the N20.