Right now, I have a 62-1 turbo going to a muffler shop crushbent downpipe. Would switching to a mandrel bent downpipe really make that much of a difference?

 

Depends on what you mean by "crush" bent. Whenever someone says that, I always think of the "accordian" style exhaust pipe you can buy at any auto store. That stuff SUCKS. However, if you mean just a regular exhaust bender, then it will make a different, but not that great.