wasn't aware downing atlanta had an e30 set-up, just the e36 version. a pic or two would be nice.

- changing the SC pulley changes the boost
- most downing kits are roots type eaton based and have no intercooler as such
- that is why they are kept to between 7-8 psi. 5 seems super safe zone or just worn maybe
- if you up the boost significantly you will likely melt the motor or otherwise fatally destroy a vital component or two
- unless you undertake expen$ive internal upgrade$ and $upporting mod$

it is not undoable however. check with the boosted forum for more info.
good luck and have fun.