Muffler options for 993 Heat Exchangers with flipped flanges

[polizei]

Hey guys,

I'm looking for a good exhaust system to compliment a 3.4L street car. I need heat and to be able to hold a conversation while on the street. The 993 heat exchangers seem like a great economical solution that will flow better than SSIs. Are there any mufflers that will bolt onto 993 heat exchangers AND fit with a 3.2 Carrera? What are your thoughts on this setup?

Let me know if you have a set of 993 heat exchangers with flipped flanges and muffler available for sale.

[Lukesportsman]

I have flipped 993TT's but I'm using GT turbos for mufflers

But to your question: Yes they flow great for the money but you'll need a custom adapter pipe to connect it to any existing muffler. Ben would be the one to talk to or Brian as they both have worked with the HE's and if nothing else start you in the right direction.

[arrivederci]

Ben @ M&K has a jig to make a muffler fit this assuming you have the Bischoff heat exchangers, not the Gilette ones. That should work without any additional mods. I have one of his 911R style ones that will go on my 3.6L install.

Others with 3.6L conversions that are running the 993 exchangers have gone the custom route with various magnaflow, flowmaster, and burns mufflers.

[polizei]

Are there adapters available to connect from the exhaust outlet of the 993 heat exchangers to the inlets of OEM 2-in mufflers? Is that what you're saying? Or would an OEM muffler need to be modified to be fitted to the 993 heat exchangers?

[RarlyL8]

I believe this is the muffler you are talking about. Don't know if Ben makes this one any more but can find out.

[polizei]

Brian - That's exactly the one I'd like. I'd also be interested in one a set of M&K 911 race mufflers. That'd be great if you could chat with Ben. I sent him a message the other day too. Thanks!

[Jack Olsen]

I've got a Magnaflow in there.

[polizei]

Jack - that looks great. How's the volume in the cab when driving around town?

[rothaus]

I just converted my 3.6 (964) from 3.2 HE to 993 HE. I also used a Magnaflow muffler.

Here are some pictures. This system is very quiet, I did not drive it around, I just finished last weekend. I will see how it really sounds next saturday when I take the car to the dyno.

[jc.capcity]

Hey guys, '83 3.0 with SSI Cat replacement into stock muffler. Can you comment on performance and sound difference between K&L and Danske. 1 in 1 out. Id like a little more sound and any performance I could get.

[sempaipaul]

Originally Posted by rothaus

I just converted my 3.6 (964) from 3.2 HE to 993 HE. I also used a Magnaflow muffler.

Here are some pictures. This system is very quiet, I did not drive it around, I just finished last weekend. I will see how it really sounds next saturday when I take the car to the dyno.

Wow that looks great! Where do all of you guys but the proper flanges to weld to the exhaust so they mate up with the 993 heat exchangers? I know I can get a shop to bend some tubing and weld it up nicely to a muffler --- however, the flanges is what I anticipate they would struggle with. I love Insta-G's "happy crab" set up, however at $1100 its quite steep in my opinion....

Thanks,

[Joe Bob]

[Joe Bob]

Yes, I have a trailer hitch.

[sempaipaul]

Where do you guys get the flanges to weld on to your custom muffler set ups to mate with the 993 heat exchangers?

[rothaus]

The crossover tubes from old HE from SC or Carrera got the same flanges



Hope this helps.

Cheers
Engelbert

[911pcars]

Due to the more extreme exit angle of the outlet flanges, it's a little more challenging to adapt the Gillet-style 993 heat exchangers to a muffler system. Because of the restricted space in an early 911, a factory-type muffler won't fit with either Gillet or Bishoff HE.

Factory Gillet HEs prior to flange "flipping" one bank:


Here's some images in my Gillet folder:

with cats:


with Magnaflo mufflers:




Some owners modify the outlets to shorten/straighten gas flow to the muffler:


I like this modified outlet and system recently posted by cmpski:


Sherwood

[rbogh901]

Originally Posted by Jack Olsen

I've got a Magnaflow in there.

Jack, are you around and do you know where to source flanges like these to have a system welded up? Are they something a basic exhaust shop would have?
Does anyone know where to get the "dough-nut" style connectors used in 964 exhaust systems?

[rennch]

This thread is of particular interest to meas I've just taken possession of my 3.6 and have the stock heat exchangers. Looks like it's cot a forgone conclusion to go with headers. I just need to figure out how to mount a sport exhaust or similar setup to go out under the bumperettes.

[Jack Olsen]

Originally Posted by rbogh901

Jack, are you around and do you know where to source flanges like these to have a system welded up? Are they something a basic exhaust shop would have?
Does anyone know where to get the "dough-nut" style connectors used in 964 exhaust systems?

I harvested them from the old muffler. I assume a muffler shop could weld on two new pairs if you don't have the originals.

[ischmitz]

The flanges come from the dual-cat center pipes of 993.