How to eliminate exhaust drone?

Ricks951 · 12-16-2012, 01:39 PM

Hi guys, haven't posted for a while but have a question I hope you can help with. I have an '05 S with a Fabspeed race exhaust installed last year. Great unit, traditional Fabspeed quality, very light, outstanding looks, and easy installation. I had a Fabspeed on my '86 951 for ~10+ years and never disappointed, however, there is a lot of drone on the S below ~3K rpm - above that it sounds great, just like a race car. Is there something I can do to reduce the drone to drive around town and remove at AX or track events? I'm sure I am waking up the neighbors and the wife isn't crazy about the noise (OK, that's not that big a problem since she'd rather be in her CRV anyway...).

Any help appreciated, TIA,

Rick

JFP in PA · 03:22 AM

Quote:

Originally Posted by Ricks951

Is there something I can do to reduce the drone to drive around town and remove at AX or track events?

Sure, remove your current exhaust. It is one of several that drone to the point that people pay to have them taken off...............

Nostril Cheese · 12-16-2012, 05:17 PM

Fabspeed? quality?

Hatzenbach · 12-18-2012, 05:53 AM

Can't be done

derfo · derfo's Garage

Hi Rick

I new about the drone before I bought my exhaust system. What was missing from the car when I bought it though, in my ears was, the music from the exhaust. So I bought a system knowing the drone would be there, I love the drone but others in the family find it annoying. What I thought of doing was, to start with anyway, just to soften the drone a bit maybe, was cover the rear box in a blanket. Not just any old blanket. I have a fire blanket at home which I am going to cut to shape. It will follow the shape of the back box on the top, and overlap slightly. Two pieces will be cut to the same shape and these will be sown together (fire proof thread of course). The blanket will be filled with 25mm of insulation material. When its all sown together it can be fastened to the top of the back box with thin SS Tye's. I will let you know how I get on with it. My beast is a 2002 Arctic Silver Boxster S.

Ricks951 · 12-18-2012, 01:58 PM

Thanks for the replies. Curious about the fire blanket wrap idea and hope it works out. I knew that there would probably be some dronning as well when I got the system, but I like to hear what I'm driving - previous cars have been a 911 FTL with test pipe and a 951 with full 3" exhaust so those cars were loud as well. And above 3K it's superb. Are there any real short resonators that might work?

Rick

Hatzenbach · 12-18-2012, 08:28 PM

I had a GHL once which was famous for it's great sound and it's brutal drone
I once read somewhere that someone got rid of some of the drone by wrapping exhaust wrap around the two big cans. Never got around to trying that and sold the damn thing after being stuck in stop and go for one hour (RPM were for one hour in the "sweet spot" for optimal drone), when I got home I had ringing in my ears for hours and took the thing off the next day

mikefocke · 12-19-2012, 06:56 AM

Never understood the obsession for loud mufflers. There is a reason us old guys wear hearing aids and it is that ears are good for only so many cycles of loudness. Crank that music up or be around firing big guns too much or gut that muffler and you won't see any impact immediately but you will.

Hatzenbach · 12-19-2012, 08:55 PM

Quote:

Originally Posted by mikefocke

Never understood the obsession for loud mufflers. There is a reason us old guys wear hearing aids and it is that ears are good for only so many cycles of loudness. Crank that music up or be around firing big guns too much or gut that muffler and you won't see any impact immediately but you will.

Actually it's the other way around: The more I loose my hearing the louder my exhaust needs to be, so that I still hear it. Of course now I loose my hearing even faster, so I need an even louder exhaust ...and so on...

Steve986 · 12-23-2012, 08:48 AM

I have a custom Magnaflow exhaust, sounds like a race car! Truly awesome, if you like that kind of thing. Drones like hell under 3k. If I'm on the highway for any extended period I wear earplugs. Although, in Kansas we have a 75MPH speed limit on highways, so that tends to keep my engine above the drone-zone. It's no problem in town, usually. I try to keep RPMs a little higher to avoid drone.

Steve

Cajundaddy · Cajundaddy's Garage

Porsche Motorsport sound without drone?
Make the Pedro Sport Exhaust

It's an acoustics thing. Any two-can exhaust will resonate at a certain frequency (often 3k). The stock exhaust brings both banks together into a sophisticated wave-cancellation chamber that acts much like those Bose noise cancelling headphones. It is tuned to remove the nasty resonance while still letting the sweet Porsche sounds come through. The Pedro mod allows more of the "attitude" to come through while retaining the wave cancellation chamber. This is the best of both worlds as far as I know. More louder but still sweet sounding without 3k drone. It is also easy on the wallet.

Ricks951 · 12-23-2012, 02:04 PM

I've seen the Pedro mod, but is there a mod like that for a '05 S? It looks to be more complicated than the earlier mufflers. The secondary cats are huge! Any way to bypass those?

Thanks,
Rick

Sboxin · Sboxin's Garage

We have an '02 Boxster S with a Billy Boat droan monster -- sounds great at Ax
and track -- but that 2-3K droan doesn't go away - I just get to 3K as fast as possible.

I have the stock muffler, but haven't put it back on in 7 years...

So......the options are go back to stock or put up with it.

It would be nice if a Forum reader has a simple fix for this?

Regards,

Joe-B · 12-23-2012, 06:39 PM

Quote:

Originally Posted by Hatzenbach

Actually it's the other way around: The more I loose my hearing the louder my exhaust needs to be, so that I still hear it. Of course now I loose my hearing even faster, so I need an even louder exhaust ...and so on...

Maybe you need to tighten up your hearing if it's loose

, or you might lose it

! (How's that for a first post?)