I have a 3" cutout on my firebird. It works great. I'd put it/them on after the H or X pipe, if you have one. The great part is if you get annoyed after a while, you can just shut it back up and run quietly again. The space requirements aren't too bad. I don't have pipe after my cutout section, and essentially all you need to do to put one on is cut off the same amount of pipe the y pipe takes up and either weld it right in or vband flange it and bolt it down. The switches can be tricky, and you will need to figure out a good way to run the wires.

I have a QTP unit and it has been running well for 4 or 5 years.

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2001 E53 3.0 5pd