Megaphones on a 911 sound amazing IMO. Might be a bit tough on the street though - haven't tried that.

the 4 rotor versions run at LeMans were epic. Like you could hear them coming a mile away. Most people hate the sound for one reason: Too early in the AM, LOL.

(The carb versions lose the chokes for racing, and they are notoriously difficult to warm up on cold mornings without chokes. They require revving and revving. For mine I swapped to a street carb with a choke then swapped over for the race....if set up right it's a 5 minute deal. I like to be respectful of the neighbors in the paddock).

This is absolutely true. Especially the first gen RX-7s for some reason. There were several of those in the ChampCar endurance series and I would wince every time I passed or was passed by one. Painful.

I ran a set of George's headers and Supertrapps (modified to run 18 discs) on my 2.7 back in the '90s and in my opinion that was one of the best sounding exhausts I've ever heard. If they weren't so anti-social, I would fit them on my 3.2.

I am a sucker for the sub $100 muffler challenge! I gave this one a try recently: https://www.summitracing.com/parts/sum-633264

Nice polished look, it does have a X flow inside but there is a decent amount of volume inside of the cross intersection which i figured might help with the two banks exhaust pulses from colliding into one another.
At any rate, it was not a sound I could stand to live with. Much less "ting" or rasp sounding but very deep and loud. Very deep. Would give me a headache in short order i'm sure.

So the Dynomax 17231 went back on again. I did have some new cracks right where the "dynomax" logo was stamped into the sheetmetal. So i welded them up before throwing it back on the car.

I tried a Magnaflow with a nice cross over inside. Found performance to less than that of the 17231... Nice note tho...

Mike--which Magnaflow? i just bot a 11386 model to put on. X-flow vs straight through like the Dynomax 17231 I have currently. So you actually can notice the performance change?

It's a few years ago now, but yes I think thats it.
My car ran itbs efi cop, decent comp bigger cams etc... approx 245 wheel hp... The magnaflow felt like a 20hp loss.

On a stockish motor I'm sure it would be fine.

These x pipe muffs are designed to flow from 1 side to the other and not from opposite sides like we do in the 911.

Midrange felt fine. It was onlt the last 2000 rpm I felt the difference and it was slower to rev out too.

Thanks Mike at this point Im looking for deeper more aggressive tone. The Dynomax 17231 sounds nice and no drone and engine (SS cam'd 964 3.6 roughly 300 crank hp).

Did you go away from the GT3 muffler you had on before as well? I know you have done a fair amount of experimentation on your exhaust. In your opinion which one sounds the best?

I helped out a buddy yesterday install his Hayward & Scott muffler. It is a gt3 style muffler with twin exits coming out the center of the car. It was made to bolt to his SSI's. I don't see this muffler listed on their website but overall he's quite happy with it.
All stainless, tig welds, lightweight. No drone, but its fairly loud. Sounds very aggressive similar to my Dynomax 17231 but less drone and maybe 5-10% quieter. We had to heat the pipes and spread them about 1/2" further apart to match his SSIs. I assume there is some variance from car to car here but 1/2" is a fair bit.
No clue on the power it unlocked but he says it feels a little bit quicker. Subjective and hard to quantify i know.
It is the best sounding of the mufflers I've had any experience with though, simply due to it being a little quieter than the dynomax.
I'm surprised how few people seem to run these or the Monty's for that matter.

http://forums.pelicanparts.com/uploa...1652713919.jpg

Interesting would love to see a video of this Pampadori.

If it's not listed on their website then I'm surprised anyone runs one!

Is this a “GT3 style muffler” because of its internal design or simply because of the outlets?

I refer to it as a gt3 style simply because of the outlet locations.

Next up we have the Borla 40474 transverse. Thinking this could cure my drone issues. Only setback is the price. i guess you pay more for made in usa. Reverse the flow for our cars and you end up with a 2 in 1 out setup.
https://www.borla.com/productImages/...in-3-large.jpg
https://www.borla.com/productImages/...in-1-large.jpg

that would be an interesting solution. Very keen to hear your results from this.

That's a big boy. 21lb shipping weight.
https://www.borla.com/products/universal-muffler-40474

Even Borla says it's reversible. I'm also eager to see/hear some results.

This one ☝️ looks good! I’m going to order it also as I see potential for my weird catalytic converter needs.

The Borla 2-in-1 out showed up. It’s big, pretty heavy and dense. Should be rather tame…or at least that’s what people claim on Jegs / Summit. Overall it’s decent, but quality is not that great. So much for US made quality. Pipes have a oval shape to them and will take work to fit. Also, 2.5” sections neck down to 2.25” at the muffler. I’m planning to cut off the 2.50” and adapt to 2.25” as I’m mating to SSI’s. As mention, I have an odd use case and need to install a cat post muffler for visual inspection by rally sanctioning rules.

If this does not work, I’ll buy the 2.5” muffler from Stainless Bros. I have been buying parts from them and been impressed. https://www.stainlessbros.com/25-dualdual-ss304-dual-thin-oval-muffler-17-oal--polished.html

http://forums.pelicanparts.com/uploa...1653230368.jpg

http://forums.pelicanparts.com/uploa...1653230368.jpg

http://forums.pelicanparts.com/uploa...1653230368.jpg

http://forums.pelicanparts.com/uploa...1653230368.jpg

http://forums.pelicanparts.com/uploa...1653230368.jpg

That was fast!
Looking forward to a sound clip and your thoughts on the sound & drone.

Edit - misunderstood the routing.

One thing I don't like as much about the Borla transverse is that the flow from the two inlets do a head on collision in a small diameter mixing area (the Y junction). One would think this is a major detriment to flow.