Why would anybony drill and tap a hole

[C6AE]

on the intake side of a throttle body?
I got one off of fleabay and there's a hole about 5/16 thread through the body near the end where the boot would go. It has obviously been added later.
Any clues?

 

[BK_CAULEY]

nitous?

probably a nitrous port.

 

[TheBocSez]

to add a nitrous nozzle.

 

[red95gtconvert]

It is for da naawwzzzz

 

[MYSTICSVT]

Most Nitrous nozzles are 1/8" NPT.

How about a boost reference port for a gauge?

 

[Euphoric306]

Most Nitrous nozzles are 1/8" NPT.

How about a boost reference port for a gauge?

sounds more likely. nitrous is usually done on the maf side of the TB so you don't have to drill into metal, just into poly.

 

[getusummm]

Actually most of the Nitrous nozzles I have seen and used are 1/16npt which is very very close to 5/16nf. Its kinda a pain because 1/16npt taps are not something you just run to the hardware store and purchase.