Ok, you've got lots of options.
The most common and most simple intake route for TT's is the single intake kit or "pop charger" as some call it. It simply is putting a filter with maf adapter on MAF in place of the bulky and restrictive stock air box. Here's a picture of the Stillen intake on my Z32 from like 5 years ago...
Another option is one of the many dual intake systems on the market for the TT's. You should reflash the computer to compensate for the secondary unmetered airflow. Now in reality this isn't necessary at all unless you're pushing 450hp+ but I'll educate you on them anyway
Here is the Jim Wolf Technology kit, it replaces the stock Y tube with a pair of elbows and simulates a dummy MAF.
Here is another companies take on a dual intake system where the piping shares a center section.
And then here is my custom setup that I currently run on my Z32. Since I am running an FMIC and eliminated the stock side mount intercoolers, we fabbed up piping and ran it directly out under the headlights and put a pair of Apex-i filters in the stock IC locations. The system is very effective and features pipes that run straight back to the turbocharges with very minimal bends. But its a custom 1-off and wouldn't be necessary in most applications (don't mind the dirt and filth on everything from being torn apart in the shop )
And here you can see how they are directly fed air by the carbon fiber ducts that are in place of the foglights and how air also gets to them around the FMIC piping by the vents for the stock IC's.
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