Steve Wong chip
 

I ordered a 93 octane SW chip today for my 88 911 cab w/cat bypass and stock silencer. I will report back to advise whether I get the 30hp seat-of-the-pants performance boost as advertized.

Very curious to see if you get the better running results many report. I guess we are lucky to have the 93 gas here. Looking to do this soon my self.

My car came with an cynex chip and I switched to a SW chip - no cat and 93 octane. It immediately idled better and had more power in the mid range where its most usable.

Please note, as I explained on the phone, the areas where it gains 30+ hp is the region past 6000 rpm. The full throttle gain differences are typical as tested below. Your low and mid rpm part throttle gains which increase by about 20%, and make the most difference in low and mid rpm torque and throttle response below 4000, cannot be illustrated by the full throttle charts below: