Dansk sport muffler & heat exchangers

[jmirandes]

Do you NEED heat exchangers to install a JP Group Dansk 1620801700 sport muffler? My '68 has custom headers but need to replace muffler and have read that states "for cars WITH heat exchangers" but no details as to why....other than I assume, dimensions...

Thanks!

jmirandes

[edmayo]

You have to have something to bolt the muffler to,,,,in this case they are saying the muffler fits cars with heat exchangers,,,,,or something that mimics the heat exchangers.

[Jeff Higgins]

Heat exchangers really are just headers, with the addition of the sheet metal box around them that provides a means through which to trap the hot air they generate and force it into the cabin for heat. The actual pipes are the same between headers and heat exchangers, save for one important difference - the flange on which any "downstream" attachments are mounted are in different locations. The flange on typical headers is located right at the merge collector, right where the three primary pipes come together. This is a good deal further forward than the flange location on heat exchangers. Heat exchangers employ an additional length of pipe aft of the merge collectors that serves to extend them back to where the muffler flange is located. This length of pipe also has kind of an "S" bend in it that effectively moves the mounting flanges closer together. If you have headers, all you need to adapt them to any normal 911 muffler is that short length of "S" bend pipe. Fortunately, this pipe is available from GT Racing as their "street adapter" pipe: http://www.gt-racing.com/porsche-911...s-part-911-sa/

In the photo of the heat exchangers, you can see where this "S" pipe lies. Imagine a plane where the three primary pipes come together - that is where the flange on a typical set of headers would be. You can see how this "S" pipe would fill the gap from there to the flange on the heat exchangers.

[jmirandes]

Just as I thought, but loud and clear now. Many thanks!