I recently ordered the Unleashed 3 inch down pipes, since not only were they cheaper than the 2.5 inch ones, but I figured why not?
They sound great! You can really here the turbo's spool up, and even thought the first set I was sent, the passenger side didn't seem to be welded correctly, causing the pipe to hit on the engine cradle, making it impossible to connect, Torrie has me send them back and sent me a new pair!
As far as the install goes:
It's basically the same as bpd1151's [
http://www.ecoboostperformanceforum.com/index.php/topic,534.0.html]
A couple things to note, its good to have an impact wrench on hand (I know he says impact driver, however even with my impact gun I could hardly get a couple of the nuts off), Wobble extensions are great to have, for the driver side/front you might have to remove the oil filter. I didn't and ended up crushing it trying to remove the top bolt.
You will NEED bolts to attach the downpipes to the 3rd cat, I got nuts from Advanced Auto that are meant to stay on (they are slightly deformed so they won't back off, kind of like a nut with the nylon center)
It is also a lot easier to disconnect the 3rd cat from the two runner hangers to get it out of the way enough and not bolt either downpipe to it until they are both installed. A jack stand comes in handy to hold the downpipe up.
You DO NOT need a lift to install them either. A lift might make it easier, however I was able to do it with jack stands. I jacked the car up and used the jack stands on both sides of the control arm and another set under the jacking points, just to be safe. The driver side/front downpipe you have to be under the car to do, which is also the easier one. The passenger side downpipe, you actually need to go through the passenger side front wheel and its just right there.
I had a couple install problems with them however, and tried to fix it as best as I could.
Problem 1: Downpipe hit a metal shield on the driveshaft assembly
Solution: Removed the metal shield, there is a 10mm bolt on either side and the pipe fits in there. (See attachment 1)
Problem 2: Because of it being a 3" pipe, the flange doesn't seem to be quite big enough around the bolt holes to use the studs. I had this problem on both of the downpipes, really just one ear on each.
Solution: Go to Home Depot (Lowes didn't have them) and buy M10-1.5 x 40 mm Socket Cap bolts [
http://www.homedepot.com/p/Crown-Bolt-M10-1-5-x-40-mm-Zinc-Plated-Steel-Socket-Cap-Recessed-Hex-Screw-803498/204281941] Also, while there, you might want to pick up a 10mm hex socket (it's like $1.97)
The bolt has a small enough radius that it should sit flush with the flange, unlike a regular bolt or even the stud with the nut (See attachments) One thing to keep in mind, not all the holes in the turbo flange go straight through, so you might have to cut down the bolt.