Any pictures of this? Does the brake line go into the muffler at all like a pitot tube? or is it just to make a generic hose connection to the exhaust without melting anything?
I put it in the pipe anywhere north of the muffler, but try to be within a foot or two of the muffler.
NO PITOT.
Just inserted a half an inch or so at 90* to the pipe.
Pressure is supposed to be equal in all parts of the system. In reality it tends to pile up at the muffler which is generally the restriction. Plus the gauge needle tends to be more stable at just in front of the muffler, cuz most of the hammering,it seems, is going on at the Y.
The first time I ever tested,was on a pick-up truck with a cat. I used 2ft of 1/4" brakeline, between the Cat and the muffler. Cuz I didn't know how hot that tube would get. That was overkill. Subsequent tests I used 3/16 line and down to 15 inches seemed adequate. The long line tho, lets you pinch it closed and fold it over; no brazing required. And you have lots of useful line left over. Plus if you just cap it, you can use it again later, after the restriction has been removed, to prove to the customer, that he paid to have the right part removed. This gets to be real important when you have to replace an expensive Cat.