droning! what i can't hear you?

[steved0x]

I would try it stock and see how it goes. Maybe there is a,way to sandwich some high temp rubber washers where it mounts at the top to reduce harmonics, I just realized the OEM muffler is isolated at the top mounting.

[Nine8Six]

(^performance, hmm)

Wrapped from the headers all the way down to the twin mufflers. Not only it lowers the temp in the bay, it also did cancelled drone by 15~25% for sure. Still sounds amazing though... and couldn't think for a minute to cancel it all. Part of the fun

... or maybe not for someone who DD on a slow highway for 50~75 miles/day. Could be different in that case

That wrap was pretty thick. If my memory is good it was a good 3~4mm thick.

[DWBOX2000]

Nine8Six, what is the wrap you mentioned? Curious. Thanks

[Nine8Six]

Originally Posted by DWBOX2000

Nine8Six, what is the wrap you mentioned? Curious. Thanks

Its called Exhaust Header Wrap or something like that... made out of fibers. or cheap asbestos who bloody knows; wear a mask and gloves if diy lollll Some says its not recommended and you should only use ceramic coating but when living 15,000km away from common sense the wrap is then ideal

example:
2" 50Ft Roll Fiberglass Exhaust Header Pipe Heat Wrap Tape Black +10 Ties Kit | eBay

6~7+ year later, and still looking good. Better than ceramic, certainly 100+ cheaper

[Nine8Six]

If you look around the muffler intake, that is rust forming (I think). So if your exhaust is a $4,000+ unit and you drive your sport car in the rain, then maybe the wrap is not for you. Looking at this pic above, I'd say Use With Caution!

Although perfect to 'reduce' drone a tad and the heat driven by those cheap made-in-taiwan pipes & cans

[jakeru]

Originally Posted by steved0x

Yes I think the aftermarket exhausts have glass packs and will emit some fiberglass like sparkly powder you will see on your bumper at first. The guidance I read was to rinse it off with a hose and do not wipe it off as the glass may make swirls and micro scratches.

You think the aftermarket Boxster muffler designs are a straight-through, glass-pack style, like this?

[Boxtaboy]

I don't think I have any glass packing in my Dansk exhaust. I've had it for many years, and have never seen any powder residue come out of it.

[edc]

Originally Posted by jakeru

You think the aftermarket Boxster muffler designs are a straight-through, glass-pack style, like this?

Most if not all the 2 box twin tips are of this construction I'm pretty sure and look just like the 'Topspeed'. Most are similarly lightweight and from alibaba.com. I've had 2 exactly the same both 'branded' differently.

[DWBOX2000]

Regarding the same construction, were they priced the same?

[edc]

In my case they were bought about 2 years apart 1 from an ebay auction and the other as a bundle of parts as second hand but originally from a Porsche independent parts shop. You can't compare the price. There is variation in the UK on the new price by even up to 100%. That sounds drastic but some are not much more than 200GBP.

[03S]

This exhaust is a Jic-Magic purchased on ebay a couple years back. There is no drone from this exhaust. The only problem is two hangers broke off, had them welded and now ready to go back on. The temp exhaust, currently installed, has the 2800 to 3000 drone. Why the Jic-Magic has no drone is unknown. I always thought it was the longer pipes or maybe the way the mufflers are built.

[03S]

Here is my Jic-Magic exhaust that doesn't drone. What did happen is a couple exhaust hangers broke off, but it has been on for about 4 years. Just had it welded and it's ready to go back on. Not sure why it doesn't drone but I think it's either the pipe length or the muffler construction. The temporary exhaust is the lesser expensive ebay ones and it has that 2800 to 3000 drone. It's not awful but it's there. The Jic-Magic sounds so much better than the temp ebay muffler, and can't wait to get it back on.

[madmac]

so if i delete the 2 rear cats, and wrap the sweet bejeasus out of the exaust system i will kill that droning???
if it will work, i am on it!

[03S]

The only luck I've had with reducing drone was with my GHL exhaust. I used a cut down motorcycle baffle and it worked good. It did not completely eliminate the drone but it was not that noticeable and if you've ever heard a GHL the drone is deafening. I tried wrapping the pipes, but it didn't work for me.

[madmac]

what do you figure the baffles are doing?? as far as droning is concerned?

[03S]

Originally Posted by madmac

what do you figure the baffles are doing?? as far as droning is concerned?

I'm not sure, but I used a similar baffle in my Harley. Quieted down my Harley so that's why I tried it and it worked. I know the diameter and length has a lot to do with it and probably just got lucky. I was also going to wrap the baffle with thin fiberglass but didn't need to.

[jakeru]

Originally Posted by madmac

what do you figure the baffles are doing?? as far as droning is concerned?

I would speculate they are causing a restriction, which encourages less high sound pressure pulse to get out through the exhaust tips, and more of that sound energy to instead get sent across the crossover pipe (which *is* present in the GHL exhaust) so it can travel back up the other 3-cylinder bank exhaust pipe, so that the rarefaction phase of this pulse effectively cancel out the positive pulse of the exhaust gasses escaping out past the valves of the opposite cylinder bank, at the "droning" (1st order harmonic) frequency.

Would the added restriction also rob horsepower, though, and defeat the purpose of having an aftermarket "straight through" exhaust system in the first place? In the absence of having dyno data to review, I would also speculate "yes."

[madmac]

good point, but the strait through came with the car, i am just trying to tame it .

[edc]

That Jic-Magic exhaust looks similar in design to the Magnex one. I struggled to find a picture of it and I think it's discontinued now anyway. Rather than go straight through the box acts like a mixing chamber. The Janspeed, probably also discontinued, like the PSE have a similar design albeit one large box.

44FD1FD1-7618-4317-8A87-50225CA797AE-2115-000003AC666AC777.jpg Photo by sick_weirdo | Photobucket

[That986]

If you want to cut the drone down you need chambered silencers in your system.