Hey guys I am changing my coupler in my supercharger today along with changing the lower intake manifold gasket and i already have the 180* thermostat but i want to drill it, but i dont know what size bit to use? Any help would be great.

Start with two 1/16" holes, across from each other. Make sure the holes are not covered by the black rubber seal on the tstat. De-burr the holes, and rinse well before installation.

Warmer climates can run four 1/16" holes (that'* what I have).

Do what Willwren suggests & you'll be fine!
Up here where it'* cold 9 months out of 12! I ran a 180 Drilled T-stat with 2 - 1/16" holes!

If you live in the cold, it may take your car a while to warm up with the t-stat drilled since coolant is always flowing. So if you like the warmth I wouldnt drill it. however, Thermostats are cheap enough and easy enough to install that you can buy 2 and drill one for summer use, and keep the other for winter use. just a thought

This has probably been asked before, but oh well! What does a 180 degree thermostat provide performance wise over the stock one, my ride is a 01 ssei, will i notice a change? Thanks :?:

What you will notice is your warm up time will be extended and your fuel mileage will decrease if you drive short trips.
The final temperature will end up about the same as before you drilled it.
It'* mainly a racing trick that allows a cooler engine for a longer time....while waiting in the staging lanes.
Because of my shorter trips, when I tried 4 holes, the engine was failing to reach operating temperature and would throw a code and trigger the SES light...the newer cars are programmed to detect a thermostat that is stuck open.
ZZP sells a modified engine coolant temperture sensor that will trick the computer and allow you to run with even a 4 holed stat.
I now have only one hole drilled in mine and it works fine without the tricked sensor.
Two holes may also work. The pre-00 cars are less sensitive to this mod.