Air Pump Question
 

91 S5 stock w/corksport catback:

Recently, I popped another alternator belt, so since I had given it the proper amount of tension, I figured I should check the pulley, and I found some pretty rough spots on the alt. pulley.

I decided to replace the pulley, and the most cost effective method was a dual alt pulley kit from Banzai.

Anyways, my real question was, I need to swap to emissions legal very quickly, so the air pump is staying in place, but iirc the air pump helps with the variable intake ducting. Should I use only the one part of the new pully and keep the air pump cycling, or should I just remove that belt and double alternator pulley they car?

This is my daily driver, and I don't want any streetability to change.

Whether you need it for emissions or not, the air pump isn't going to sap much of any power if you leave it running. Not too familiar with the VDI intake system on the S5 NA's, but if they use the air pump, you won't want to remove it.

My advice is to just keep your dual belt alternator pulley and run it with the single alt belt & run the air pump belt just like stock.

Thanks!

I had a feeling that was my best bet. Now if only it would warm up I could get this done.