GT3 Muffler Mounting on a '75 with a 964 motor

[Duc Hunter]

I have a GT3 muffler and all its brackets to put into my Rat Rod. The motor is a 964 motor, and has the A/C bracket removed. Also it uses a 3.2 style rear engine mount. The car has B&B headers as well.

To mount the muffler to the engine can I use the GT3 brackets? I some how doubt it. Can I use a 3.2 muffler bracket? Do I need to fab my own up? Should I just not bother with a bracket? How have people done this?

[RarlyL8]

We've done a bunch of these, doing a couple right now. Bracket is mandatory. You can use the OE bracket if it is modified. Much simpler to make your own and strap it to the muffler body and bolt to bottom of engine console. You don't want this muffler moving around or vibrating.

[Duc Hunter]

Appreciate to advice. Thanks.

[Tom '74 911]

I run a GT3 muffler w/Fabspeed headers on the 964 3.6L engine in my '74 911. If you run into issues, I'm happy to post some pics. I can't remember off the top of my head how it's mounted... been a while since I needed to know that, so it was purged from my brain/hard drive!

Tom

[V10eatr]

Pictures would be great.

[eastbay]

I saw that Dansk is selling a couple of GT3 muffler to air cooled car mounts now.

[Steve W]

Quiet muffler that doesn't kill power, does one exist?

Quiet muffler that doesn't kill power, does one exist?

[RarlyL8]

"Building" a bracket for this application is beyond simple and inexpensive. A length of aluminum bar stock with 2 holes drilled for the bottom engine console and 2 clamps. Hang the muffler off the OE 911 bracket and secure the clamps. That's it.

[wildcat077]

Originally Posted by Tom '74 911

I run a GT3 muffler w/Fabspeed headers on the 964 3.6L engine in my '74 911. If you run into issues, I'm happy to post some pics. I can't remember off the top of my head how it's mounted... been a while since I needed to know that, so it was purged from my brain/hard drive!

Tom

Hey Tom,

Please do post some pictures ...
I have a 95 3.6 with Fabspeed headers in my 89 and i find the drone to be quite painful between 2 and 3 thousand rpms ,maybe it's the Fabspeed RSR muffler , but i would like some feedback on the GT3 setup you have !

Thank you

[mikedsilva]

Originally Posted by RarlyL8

"Building" a bracket for this application is beyond simple and inexpensive. A length of aluminum bar stock with 2 holes drilled for the bottom engine console and 2 clamps. Hang the muffler off the OE 911 bracket and secure the clamps. That's it.

That looks good and simple. When hanging off the stock muffler bracket, how does the exhaust tip line up with the bottom of the bumper?

[mikedsilva]

Originally Posted by eastbay

I saw that Dansk is selling a couple of GT3 muffler to air cooled car mounts now.

Got a link?

[mb911]

I think it was Bursch on Instagram not Dansk.

[-Levi-]

Here’s my bracket using the stock gt3 straps

[eastbay]

Originally Posted by mb911

I think it was Bursch on Instagram not Dansk.

Yes it was Bursch, my bad. Nice looking brackets

[mikedsilva]

Found it...

[Duc Hunter]

Originally Posted by mikedsilva

Found it...

Since I have converted the car to a Carrera RS style engine mount I decided to order the Bursch part.

[Tom '74 911]

That Bursch mount looks nice. Finally had a chance to get to my car and take a few pics. I couldn't find any markings on the mount so I'm not sure if it's commercially available... Rothsport built this motor for me and sourced the muffler and mount. Hope this helps!

[Duc Hunter]

Knowing Jeff Gamroth & Co (Rothsport Racing) that looks to me like they built the mount. Good quality work. I hope to get mine mounted up this week and will report back. Have to also build the y-pipes to connect to my B&B headers, with vacuum valves for the bypass side of the muffler.

[Tom '74 911]

Originally Posted by Duc Hunter

Have to also build the y-pipes to connect to my B&B headers, with vacuum valves for the bypass side of the muffler.

This is an interesting bit of hardware that I do not have as part of my set-up... yet. The GT3 muffler does drone some, but I guess I've found it not so intolerable that I've been able to find the motivation to deal with it... I'm interested to hear how it works when completed! If there was a bolt-on kit that existed, I'd have for sure installed it - but nothing like this is ever "bolt-on". : ) : )

[Hulley]

I have a 991 GT3 muffler I would love to use with my 79' SC, I am wanting to get SSIs so I can retain heat. How doable is this? Technically, the muffler is at my buddies shop about 4 hours away, so the next time I see him, I'll grab it.