There are plenty of DIYs on pulleys so this post focuses only on the Dinan A/C belt.
Today I installed the Dinan pulley for my MY2013. It has the doubled sided A/C belt. As many have previously posted, the belt is short and is a b!tch to put on. I did my research before the install so I knew this going in but I didn't realize how difficult it would be. I referenced both the Active Autowerke DIY PDF and the Macht Schnell youtube vid. Both were extremely helpful. Thanks to both Active and Macht Schnell for putting these out. With the help of these resources, the install was very straight forward except for the A/C belt.
Like I said earlier, the damn belt is way too short. I am not sure what Dinan is thinking here. It could use at least another inch.
First, I heated up the belt with a heat gun while trying to stretch it out. It was cold today so I am not sure if this really worked or not. After a few hours fighting with it, I realized the only option was to get it over the tensioner last. The last pulley you put the belt over needs to be smooth because you can't get it over any of the pulleys with a lip and grooves. The only options are the idler (space is too tight - see below) and the tensioner.
The idler pulley needs to be removed in order to get the old belt off. When putting the idler back on, I threaded the belt over it (this is a very tight space due to the aluminum A/C hoses there) and put the idler back on, but only threaded it a bit. Leaving this pulley loose provides a little extra play in the assembly. I even tried to pull the belt over the front a bit for extra play. As you will see if you do this install, you will need every little bit of length you can get.
Then I routed it over the pulley on the bottom left (not sure what accessory this is). Then I put the ratchet on the tensioner and the belt over the ratchet so the belt rests on the ratchet. This is very important. I couldn't get the ratchet under the belt any other way.
Then I pushed the tensioner down and put the belt over the crank pulley and let the tensioner back up. Now the belt is resting directly on the ratchet. Then I bottomed out the tensioner and began walking the belt over the tensioner rib by rib. Even with the tensioner bottomed out, it was an extremely tight fit!
I hope this helps anyone planning on doing this mod. I am sure I will get some Dinan hater posts but whatever. I chose this pulley ultimately because Dinan matches the factory warranty. If my car was out of warranty I probably would have went TMS.
As for performance, I finished the job quite late so I have not had a chance to get out and push the car. I did take my wife to dinner in it though and it certainly felt more rev happy, but I might just be delirious from working on this all day!
I will post an update on the performance when I have a chance to get it out and push it a bit.