May have found a solution for the drone on the cheap ebay exhausts!

[Kboggs]

With no major modification. Someone on a 986 facebook page installed this baffle that is $10 on amazon! I have one i took off my cat due to the drone, wish I hadn’t now, but if anyone wants to pick up in the charlotte nc area.




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[mikefocke]

Is the low drone better or worse for your ears. Those rumbles you hear on some bikes are the worst. An hearing aids can be more expensive than any good muffler system.

[Boxstard]

You buy a less restricting exhaust then add more restriction to it... not very logical to me. I know this is about a cheap solution for more sound, but in that case I'd rather gut out and reduce restriction inside the stock exhaust, cutting out inner pipes, add bigger bypass holes, etc.

[tommy583]

I have tried the baffle set up in a cheap Ebay exhaust. I tried different size ones, different places in the exhaust, only one side and both sides. In the end I was never really happy. I ended up just modding the stock muffler. So much better. It sounds like a proper sports car now and no drone.

[99Roadster]

Originally Posted by tommy583

I ended up just modding the stock muffler.

So Tommy what exactly did you do to the stock muffler ?.....I have a 99 base with the stock muffler and would like to hear what you did.

[rfuerst911sc]

Speaking for myself I wanted an aftermarket muffler for weight savings and sound . The OEM muffler is a tank . I have used a GHL with inserts in the tips and it was close to what I wanted but not quite . I have used a Mille Miglia which is a single can muffler similar to stock .

The MM I have not played around with inserts yet , I think it has great potential . I pulled the MM and am currently running a stock S muffler with bypass pipes . My engine is very unique and has a VERY unique exhaust note . I was very surprised how loud the S muffler is with the bypass pipes .

Going on memory the GHL is 20 lbs. lighter than stock , the MM is about 15 lbs. lighter . That is a lot of weight removed hanging under the bumper . In my opinion taking a high flow muffler and tuning it for the sound you want is ok , I highly doubt tuning it will ever make it as restrictive as the stock muffler .

[tommy583]

Originally Posted by 99Roadster

So Tommy what exactly did you do to the stock muffler ?.....I have a 99 base with the stock muffler and would like to hear what you did.

This is what you need Internal exhaust mod

[particlewave]

Originally Posted by tommy583

I have tried the baffle set up in a cheap Ebay exhaust. I tried different size ones, different places in the exhaust, only one side and both sides. In the end I was never really happy. I ended up just modding the stock muffler. So much better. It sounds like a proper sports car now and no drone.

I second that.
A few pounds is well worth proper sound with no drone.

[PaulE]

As a casual observer of these drone topic threads, it seems to me that the cheap eBay mufflers drone because one thing they all have in common is there is no cross-over pipe between the two mufflers. So there is a completely separate exhaust system for each cylinder bank and at a certain rpm the two separate exhaust streams create the drone. If you look at the Fabspeed maxflo muffler it has a cross-over pipe between the two mufflers and their latest edition also has a cross-over pipe in the exhaust tips too. The Fabspeed unit is a lot more money than the eBay ones, but perhaps adding a cross-over pipe between the two mufflers on an eBay unit would eliminate the drone.

[tommy583]

From what I've heard the Fabspeed exhausts still have some drone. The maxflow has less drone than the race muffler setup. I've also seen threads on here with people welding in a crossover pipe on ebay mufflers, they report that there is still drone. I stand by the internal mod as the most cost effective solution, followed by the external pipe mod.

[PaulE]

Originally Posted by tommy583

From what I've heard the Fabspeed exhausts still have some drone. The maxflow has less drone than the race muffler setup. I've also seen threads on here with people welding in a crossover pipe on ebay mufflers, they report that there is still drone. I stand by the internal mod as the most cost effective solution, followed by the external pipe mod.

Good to know, so far I have held off on changing from my stock muffler. I would hate to spend the $1,600 for the Fabspeed unit plus installation labor and get some drone. My car sounds great to me with the stock muffler, Fabspeed Sport headers and Circuit Werks mid-pipes.

[aparke4]

What size for the insert?

I have 2 pairs of flowmaster hushpower mufflers that drone nicely between 2.5-3k. I found a shop that can install a cross over pipe for about 200 and make it removable for clutch, etc. It is going to be tight but with the skid off there is room to match the stock size exhaust pipe. Flowmasters are 2 inch, smaller bodied mufflers. Took out second cats... These were supposed to help with drone but its the off setting exhaust pulses from cylinders that the boxer has that creates the drone with two seperate banks.

https://www.holley.com/products/exhaust/mufflers/laminar_flow_mufflers/super_hp-2_series/

For 10$, I might try finding a home on the passenger side pipe instead of engineering a J-Pipe and trying to isolate the hZ that causes the drone.

For us boxster owners, we only have about 8 feet of exhaust so if you have ever dumped an exhaust under a Jeep or Truck, you know how loud it can be ever with 6 cylinders!

[PeterBleakney]

Originally Posted by tommy583

From what I've heard the Fabspeed exhausts still have some drone. The maxflow has less drone than the race muffler setup. I've also seen threads on here with people welding in a crossover pipe on ebay mufflers, they report that there is still drone. I stand by the internal mod as the most cost effective solution, followed by the external pipe mod.

Confirmed. I put a Fabspeed Maxflo on my 2001 Boxster S, and while it sounds fabulous above 4000 rpm, the drone between 2000 and 3000 is a drag. I'm thinking of doing the internal mod to my OEM muffler and putting the old system back on. Or maybe keep the Fabspeed cats and bypass pipe and graft the old muffler on. Has anybody done this?

[boxxster]

I would imagine it would be easier to just buy a set of cat bypass pipes on ebay (I paid about $150 for mine a few years ago) than to make the fabspeed mid pipes work with the stock muffler and u-pipes. I have a set on my 04 S with the stock headers and muffler. I'd prefer it a bit louder, but the trade off is that there is absolutely no drone. The car sounds more or less stock except at full throttle and/or high rpms where there is a nice rasp and a bit more volume. I've driven a Cayman with the maxflo system and know what you mean about the drone/resonance in that rpm range.

[PeterBleakney]

Thanks for this!