I'm nearing the completion of a supercharger install on my '00 Honda insight, and I cannot find any aftermarket solutions, and running it off the serpentine belt is not going to happen, no room. Would I cause any damage by simply getting the pulley size I need from elsewhere, and simply welding it onto the stock pulley? This is the ONLY thing holding my back and it's driving my insane.

 

There is a site that makes custom pullies, forgot the url though. I am sure you can find it easily. Shouldnt be that expensive, and you wont risk grenading your motor when you warp the pulley by welding on it. Basically it could be done but chances are very slim you'll get it right.

EDIT: Pulleyboys, I have seen them do custome stuff for other people, try it out

 

It could be done if you align the pulleys along the same center somehow. Although I would recommend balancing it if you do that. Best bet would be to machine a single piece on a lathe so the centers are in the exact same spot, and even then I'd look into getting the rotating assembly balanced if you want to get detailed. Just don't weld the pulley combo to the crank.

 

I don't know about the insight pulley, but there's a small register in the S2k pulley you can use to centre another pulley with a small shoulder and just bolt it on there (right hand pulley):

 

This is the best solution, have a custom crankshaft pulley machined.

You would also need to get the rotating assembly rebalanced.

Just welding it on, you'll still need the rotating assembly rebalanced, and you run the risk of the additional piece not being concentric with the pulley.