Cast OEM compressor bracket mods
This bracket requires quite a bit of grinding.
First, you need to cut off the original compressor mounting holes to allow the alternator to slide up and down to tension the belt. These are the threaded ear holes that stick out at the very top of the bracket.
Second, You need to clearance the back side of the brack to allow room for the STIs electronic TB when the manifold is reversed. The throttle loom/plug on the side of the TB will not clear unless this is done. This requires mucho grinding as about .25" is interfering with the plug. (Parially shown at top of pic)
Third, You need to cut the front surface where the idler pulley was mounted onto this bracket. This is to provide a solid mounting sulface to mount your new pulley to. The problem is that you need to cut it so that your new idler pulley is in the same plane as the rest of the pulleys. You will be going to a single belt system. I just redrilled and re tapped one of the existing holes to mount the new idler pulley.
You will need a Gates Micro V belt K050460 (5 peak, 46in long)
Length will depend on size of idler pulley. It is always a good idea to get about 3 sizes and take back what you don't need. I measured my belt track with a tailors tape with the tensioner adjusted to get the smallest belt size. Belts should be about this length due to the belts setling into the grooves and stretching. It may be difficult to get it on at first, but just get a socket and turn the alternator pulley to ease it on.
You will also need a .75" wide back side idler pulley. Make sure it is ball bearing and is rated upwards of 9K RPMs. Mine was found at
ZFH-5212 3.25 .75 3.75 5 Flare .472 203 .669 1.00
I posed like I was needing one of these to "sample" for my Engineering project at work. They sent one to me for free to "sample". Normally they are about $12-$15. Idler pulleys are semi hard to find, especially BB ones. Problem is that this Co. has a min order of $100.
I tried McMaster Carr, but couldn't verify any BB pulleys to work. If you find one please post.