I thought i would write up a little tutorial for those who are interested in installing a Intake temp sensor, and/or boost gauge bung for monitoring their engine vitals. If there are any suggestions or different ways of doing someing/diffrent steps. Please chime in, the more info that can be packed in, the better.
Drilling the y pipe isnt a complicated process, but as with anything that you havent seen visualy, one could be a bit cautious about attempting this mod. Pics make it easy.

Before we start with the pics. I personaly perfered the ideal of installing these sensors into the y pipe, vs installing them into the "factory" intake plenums for a fiew reasons, first being that the y pipe is an easier pieice to tig weld up if you want to fill the holes back in, and grind down the inner and outer surface back to stock, vs the plenums. Kinda hard to get a grinder in there to smooth the inside surfaces.
If you have the needwings plenums, then your allready off to the races, they have a pre welded bung if im not mistaken.

Also if for any chance you screw up the y-pipe, its a bit easer on the wallet to track one down. The down side is, if any, installing a bung/sensor could potenialy ever so slightly reduce the volumetric flow through the pipe, but if done with optimal flow path in mind, you shouldnt have a problem.

Ok, first is to get the y pipe off, your going to have to take the plenums off, unless there is a way to do this without taking them off, please chime in, i spent about 30 min the other day just trying to slide the rubber gaskets up the plenum pipe so i could slide the y-pipe out the back. but to no luck. So off they came, this is also a good opportunity to check for plenum to head leakage, and redo the threadlocker on the bolts. Luckly for me i was able to spot a place on the inner diriver side plenum that looked to be slightly leaking. Also theres a crevice between the plenum and SC where dust and stuff can settle, its good practice to use a dust buster or vac to suck away any crud that could fall into the head intake holes before going any further. I wish i would of gotten some pics of the whole process but i was on a roll takin parts off then it dawned to me that i should probably do a little modding thread on the forum

Ok with the hose clamps loose, pull the electircal pulg off the intake temp sensor, then pull the y pipe off, and wiggle off the intake sensor from the y-pipe, its just pushed and has o-rings to seal it. Now begins the fun!

At my disposal i had my mill, but this mod can be equaly achieved with a good drill press, vise, and center drill. You dont actually clamp the pipe in the vice, you dont want to bend it or crush it, its just to hold it snugly in place as you work.


Y pipe



First i began with drilling for the IAT sensor, installing it directly behind the factory sensor i thought would be a great spot, placing it behind the sensor helps reduce the flow restriction then putting it some where else because the flow is already diverted by the sensor right infront of it. Plus it looks cooler.




Use a center drill first, this will help pervent the bit from wandering around when trying to drill for the tap.




I used a Q size drill (.332) but you can also go with a 11/32 bit if you dont have a full tapping drill set.



Now comes the hard part, tapping. Because a 1/8-27 NPT thread is so fine, any wobbling or skewed threading as you begin, can screw up the thread. In the drill chuck i actualy have a spring loaded punch, on most taps they will have a dimple in the square head, thats what its for. Using a centering spring pin to hold the tap straight as you begin the thread.




The 1/8-27 NPT, is a tapered tap, so dont go through the hole with it, go about 1/2 way then back out and test your sensor, you want a snug, not loose fit. Also dont cross-thread the sensor. 27tpi is fine, and will cross-thread with ease.