I just got an 91 n/a, the car is perfect (pics soon), but there's only one thing that bugs me, I previoulsy had an s4 and to my knowledge the auxilary ports on s4's are exhaust driven, right?, now, on s5's, to my knowledge, the air pump controls them, right?, the belt on my air pump is off, does this mean the auxlilary ports aern't opening?? The car doesn't loose power at the 3500 rpm mark, which is where they open, but then again i've never driven an s5 before, it feels a lot more powerful than the s4, but i don't know if they're opening or not......any help??

 

You got it - no air pump - no aux ports or VDI. Power seems to go flat at ~4K.

Also without that belt, the fan pulley will want to slip at high revs.

 

Put the belt back on! Without it the waterpump pulley can slip and you can overheat it.