04-09-2013, 08:28 PM
Join Date: May 2011
Location: Gaithersburg, MD
Total Cats: -13
Downpipe Fastner Question
My downpipe is currently connected to my turbine using (5) 20mm stainless (A2-70) bolts. I would like to replace them with ARP stainless 12 sided 25mm bolts in order to make installation easier and so that I have more threads engaged.
However, over time the receiving threads in the turbine housing have become slightly deformed such that I can only screw the ARP bolt in a little (1-2 threads), and the existing bolt only up to it's normal point of engagement (~10mm). I have chased the threads with a thread restorer, and they are not damaged. The bolts have identical threads, so no problems there.
1. Is the ARP stainless hardware appropriate for this application?
2. Since I'm not having any problems, should I just leave well enough alone and suck it up? (It's a real PITA getting the six sided bolt bolts tight with an open ended wrench)
3. Or, should I run a tap through the housing threads and install the ARP bolts?
4. Or, "You fool, there's a better solution!"