[Bob's944]

chips plug in on 85.5 and newer... the older models can take chips, it's just alot more because it's not just a chip... they get 10-15 HP but you have to pump premium only too.

exhaust can be 10-20 HP depending on how much you do, with the most coming from a test pipe arrangement.

K&N and ignition upgrades don't add much HP, maybe a couple each if yer lucky, but should help with efficiency and gas milage.