This is a completely bolt-on affair*. The exhaust hanger bushings as supplied, are NOT good. 1. They are too short & 2. they break too easily. So We used the stock grommets (which are still a bit short). Initially, the exhaust tips ended up too close to the rear bumper valence. The tips will need at least a 1" extension to be perfect, although these are in the exact stock location. I am sure on UK spec cars the tips go a few mm beyond the valence and look a bit better.
Those with a keen eye will notice the * (asterix). Keep in mind, I am pioneering this exhaust system for use on US-spec FiSTs. The front 3 metal hangers on the exhaust system had to be heated up and bent a smidge. The rear hanger had to be replaced completely. It did not allow the tips to be positioned center in the valence and there simply wasn't enough room between the tips and valence, especially when going over bumps (they would definitely touch). It didn't look right and would probably cause the painted plastic valence to melt or discolor. I felt I needed at least 15-20mm clearance between the tips and valence to be safe. The new hanger solved it all. I will be sending that info to Scorpion. Also, the rear cross beam brace clearance was closer than what I would like to see (only 10-12mm), so I added 6mm shims underneath the brace to give the system more clearance. Other than that, the system bolts up and fits like it supposed to. http://www.fiestast.net/forum/images/smilies/redface.png
Since it was so late in the day, I did not get a chance to put the car back on the dyno (I did get baseline runs in). There definitely seems like an improvement in power and boost lag is =GREATLY= reduced. I will be completely shocked if this system doesn't produce some significant gains. Seems to really feel it's oats more at higher revs (especially after 6300 rpm) than the stock system. For those of you who are worried about this negatively effecting performance being a 3" mandrel bent system, you can safely put that to rest! And the sound... all I can say is WOW! http://www.fiestast.net/forum/images/smilies/icon_smile_headbang.gif It is definitely louder and has a more exotic, bassy/barotone sound, absolutely NO raspy nastiness & =ZERO= drone at cruising speeds. I'd say the 12-13 decibel increase in noise is spot on with their noise increase claim.