[Lee]

I'm one of the RacePro haters. I still have them on my Cutlass, but mainly because it is not yet ready to be driven on the road. I also just finished having a 3" system installed on my '73 T/A clone, and used the Borla ProXS mufflers (replacing 40 series Flowmasters).

I don't mind the RP's at idle. According to my ear, the RP's were quieter at idle than the FM's were, even though the Cutlass had significantly more HP.

I downloaded a dB "app" on my phone, I know those are not all that accurate, but it SOMEWHAT able to determine if something is louder than something else. I did not get that app until after the FM's were already removed, so no "measurement" of them.

I measured the Cutlass and the 'Bird at idle, and the dB's are basically the same. I also measured them at 2000rpm (at the back of each car), and again the sound level was virtually the same.

So the quantity of sound is basically equal, but the quality of the sound is very different. The RP's get raspier as more throttle is given, very raspy at WOT. The Borlas have a very smooth even tone, no "rasp" at all. To my ear, the Borla are MUCH more pleasant.

I try to get a video in the near future. I had the 'bird strapped the chassis dyno the other day and was going to record then, but the PC running the dyno software died... so maybe next week I'll get that done.