Porsche 986 987 Boxster & Boxster S 97-04 Top Speed Pro-1

[heymanwatchthis]

Fintro,

I had drone between (as I recall) 2k and 3k. It is hard to avoid this range while driving in town and on the highway. It was so bad my ears would ring and I got headaches, decided it was not worth it. Wish the drone could be eliminated because otherwise the sound is great, a lot of fun.

[911monty]

I would like to see someone take one of these muffler systems and weld in a balance or exhaust crossover pipe between the two mufflers to see if that will eliminate the drone. Several years ago I built a high compression 468 chevy engine with 2-1/2" dual mufflers. The drone was ear bleed bad with magna flow mufflers. SO bad my first trip onto the freeway got me pulled over. Highway Patrolman came up to window and said "I don't care what you have under the hood but It's entirely too loud" No Kidding! I then welded in 2 Flowmaster series 70 mufflers. Quieter but the high frequency from the compression was still unbearable. I had been doing some research on the issue and what I discovered was the unbalanced exhaust pulses through the system was what caused the drone. I welded in a balance pipe and the difference was absolutely miraculous. Gone was the high frequency drone and I had a deep mellow rumble. To work best the balance pipe needs to be close to the header, but I wonder if it may help. Seems to me the stock mufflers have this bypass built into them with both sides entering the internal perforated pipes.

PS looking at the Fabspeed system I see they have the balance tube.