3.2 Carrera w/ headers 2-in muffler fitment help? SCART, Dansk, Monty.

[famoroso]

Originally Posted by Bill Verburg

I put a Fabspeed RSR on mine a few years ago, they sound great, no high frequency stuff, just mellow basso, and you can even hear the engine cooling fan

No high frequency stuff ✔️
Mellow basso profundo ✔️
Cooling fan music ✔️

That's pretty perfect to my ears.


This Rothsport 3.5,.with unvalved GT3 rear box,.is not quiet, but man... What. A. Thing. It's really rather glorious, albeit, in a wife / suburban neighbor unfriendly way. There is nothing covert about throttle position vs. load, everyone knows what the driver's right foot is doing and when. I like an exhaust that makes me feel alive, but this one is borderline too much of a good thing.

[RarlyL8]

We've done a lot of the GT3 BackBox conversions on all sorts of engine chassis combinations. On this one the secondaries were sized properly for the smaller displacement air cooled engine and baffles were added to the quiet side and tailpipes to tame it down. The quiet side secondary inlets also mate properly with the muffler internals to eliminate any flow bypassing the correct path, which would make the muffler louder when the valves are shut.

[Duc Hunter]

Originally Posted by famoroso

No high frequency stuff ✔️
Mellow basso profundo ✔️
Cooling fan music ✔️

That's pretty perfect to my ears.


This Rothsport 3.5,.with unvalved GT3 rear box,.is not quiet, but man... What. A. Thing. It's really rather glorious, albeit, in a wife / suburban neighbor unfriendly way. There is nothing covert about throttle position vs. load, everyone knows what the driver's right foot is doing and when. I like an exhaust that makes me feel alive, but this one is borderline too much of a good thing.

My Rothsport GT3 has the valves. Yes they make a significant difference........it goes from too loud for conversation without loud voices, to even louder voices. So don't think that adding valves will make it more covert. Bill's Fabspeed muffler would be amazing, as I have that whole system on my 3.2. My plan would be valve one of the 2 exits. that way it will still sound great, cooling fan music, etc at low RPM. That’s how my 3.2 is setup permanently (single outlet). When I tried the second outlet it was even louder, and droned at about 2,700-3,000RPM. So my plan is open it over 4,000, which my 964 motor can do with the flapper valve in the intake. Best of both worlds.


Though as I said I would still like to try to pack the quiet side of my GT3 and see if that helps.

[stephen1070]

More information on the SSI 41mm systems for the 3.2. Would like to see a dyno run on these.

Thank you!





https://ssiexhaust.com/hoeing-exhausts/

[scarceller]

Frank, what's the black 2in with 2 out GT3 style muffler? and does it drone? I'm looking for something like that GT3 black muffler you have.

Originally Posted by famoroso

Yes, that rear valance will go in my '89 build. I will try both a Ti GT3 RS muffler with valved secondaries and the Scart GT3 tip muffler with non-valved secondaries.

That being said, I've since tried three different 2 in / 1 out mufflers on my blue '87 since my last post on this thread.

1) A Scart Riva (which is louder than their Sport)...
https://youtu.be/RpIgU2jTpWI
Ends up that it was too loud for my Club Sport-ish / mildly wife unfriendly use case (especially for 6:30a Saturday/ Sunday departures in my suburban neighborhood).

2) Monty 2 in / 1 out. Sounded better, but not as good as the 1 in / 1 out Monty on my other '87 with stock 3.2, but that's and apples vs watermelons comparison.

3) The Scart Sport (mellower than Riva) that I've currently settled on. It's more aggressive than stock, but just a bit less aggression than I was looking (listening) for.

I have a muffler problem tho, so we'll see how long before I try something new, or swap one of the others back in...

[famoroso]

Originally Posted by scarceller

Frank, what's the black 2in with 2 out GT3 style muffler? and does it drone? I'm looking for something like that GT3 black muffler you have.

It's a Scart Riva muffler with GT3 center exit tips that I had black Cerakoted. I haven't run it yet, but I knew that I'd want to A/B test it against the GT3 RS muffler with valved secondaries.

[Michael.]

Maybe I missed it, what does the GT3 center section weigh? It's off a 997 correct?

[famoroso]

Originally Posted by Michael.

Maybe I missed it, what does the GT3 center section weigh? It's off a 997 correct?

IIRC, 997 & 991 GT3 mufflers are the same / extremely similar.

I haven't weighed every part number, but the two that I have weighed...
Steel 997 GT3 muffler, naked: 15.6 lbs.
Titanium 997 GT3 RS muffler, naked: 8.94 lbs.

Mounting hardware (straps, bolts, washers, flanges & doughnuts) 3.16 lbs.

997's 80 mm double wall steel tips: 2.95 lbs.
991's 90 mm double wall steel tips: 3.44 lbs.

I haven't had a set of Titanium tips to weigh.

[Michael.]

Thank you for the info!

~21lbs all in for a steel setup. Not terrible

[famoroso]

Originally Posted by Michael.

Thank you for the info!

~21lbs all in for a steel setup. Not terrible

I haven't weighed the valved secondaries, but they'll add a bit more to the total.