Just located all the gauges (EGT and Boost), pod, mounting hardware, etc. Will purchase tommorow for a Fri or Sat install.<br><br>I use tap and die sets regularly to clean up threads. I've never done it from scratch. <br><br>1. What size pilot holes for 1/8 and 1/4 NPT threads (I have the option of either size probe)?<br><br>2. Other than keeping the tap perpendicular to the pilot hole, backing it every .5 turns for deburring and oiling, is there anything I need to do prior to starting it?<br><br>3. Finally - Is this something a guy with average mechanical skills should attempt without practicing on an iron pipe first?

 

I installed my pyrometer post turbo, so I wasn't concerned about chips/filings falling into the pipe. If you're installing pre-turbo, you're going to have to take more precautions so you don't get any chips in there.<br><br>I found the post turbo pipe mallable and very easy to drill and tap. Just choose a location that will allow your tap handle to swing 360 degrees. <br><br>A 3/16&quot; to 1/4&quot; pilot hole should be sufficient for either tap drill. The main reason, is the point on drill bits aren't actually cutting any material. The pilot hole helps insure your tap hole will be on size. I chose my location, center punched it, then chucked a #3 centerdrill and made a &quot;dish&quot; with that so the pilot hole drill would not walk, then pilot drilled, then tap drilled. Quite a process!<br><br>You are correct on your tapping procedure. Because pipe thread is tapered, just make sure you don't tap too deep. Takes a bit of trial to get the correct depth for the bushing. Don't be afraid to practice on something first, practice makes perfect. Mine is the 1/8 NPT. I thought if I buggered the first one, I could go to the 1/4 NPT one. Have fun!

 

I used grease packed into the tap to catch the chips as I went and cleaned the grease off a couple of times to keep it from loading up.
Also used a shop Vac with a crevis tool held beside the drill bit to suck up the shavings as I made the pilot hole for the tap.
Go slow take your time, and it's a piece-o-cake.

 

I used a 1/4&quot; NPT tap and a SHARP 7/16&quot; drill bit. I also used the grease on the drill bit and the tap and a 1&quot; pvc 90 with a hole drilled in the top of it and a shop vac hooked up to the other end while drilling. Also use a mech. pocket magnet to fish out any big pieces of debris. As Shovelhead said &quot;take your time&quot;. If you tap it too deep the probe or bushing will bottem out before it gets tight. Good luck Sixpack

 

Don't forget the anti-sieze on the pyro!


Tony

 

My Pipefitters Handbook lists a 7/16&quot; drill bit for a 1/4&quot; pipe tap and an 11/32&quot; drill bit for a 1/8&quot; pipe tap.

 

Picked up a new 1/4 and 1/8 NPT tap, and the drill bits to match. I'm going to remove the intake and plan to remove the turbo just to make sure I don't get to experience the fun of replacing expensive parts. If the gauge supplier has any of those intake bolts with the tubing fitting I'll look into it, but am not planning on it. Is there another way to install the boost hardware I don't understand? Thanks for your help so far.<br><br>JR