header / muffler mounting problem

[joe18d]

Evening, I have a '78 911SC and bought a set of Georges headers and extensions on the parts forum, the extensions are 11" long and the muffler I picked up is a Leistritz #4210739 ,911/1 , 2 in/2out. Well after looking at it sit on the bench for 6-7 months I decided to install it all. Well, that didn't go so well, The mufflers and extensions are mounted but when trying to fit the muffler it appears that I need another 2" or so on the extensions for everything to line up. Any help is appreciated.

Thanks, Joe in NH

[boyt911sc]

Joe,

You will get better responses if you post pictures of your exhaust and muffler set up.

Tony

[pampadori]

take the extensions to your local fabrication guy to have the extra length added. should be their easiest job all week.

[joe18d]

That is a great idea, thanks for the tip. Sorry about that on the pictures, didn't have enough hands at the time I was trying to mount it.

Joe in NH

[Mahler9th]

The OP sent me a PM on this-- I answered it.

I wouldn't pay someone else to make it work unless they have familiarity with 911s and your application. You can wind up with a mess and a huge waste of money and time.

Sounds like you have a puzzle. I am not familiar with that muffler-- let me see what I can learn about it.

In general, if that combo has worked for someone else with the same configuration as yours, it should work for you.

If you are doing your own work, then I think posting some pics can help us help you. May be a bit of a challenge to get the pictures, but it can be worthwhile.

In general the George's solutions work great without extra fab. The folks at GT Racing bought the company, and they are doing a fantastic job with the product.

Let's see some info on that muffler.

[Mahler9th]

By the way, please be aware that the extensions must be correctly oriented left/right and up/down for everything to work properly.

And it can be very beneficial to ensure that the flanges on the muffler and both ends of the extensions are flat-- if you don't, you can easily consume gaskets, despite everything being tightly bolted together.

And finally, in general in can be a bad idea to re-use the copper lock nuts after a heat cycle or two.

Ask me how I know...

[911pcars]

Suggest getting your car to a good muffler shop to extend the connecting tubes or ?. They need to be the exact length - don’t expect the shop to guess and get it right. Not rocket science nor Porsche specific. Just basic exhaust work (sounds like).

Sherwood

[joe18d]

Thanks Mike, the extensions I have are 11" long, the extensions sold by GT are 12 7/8" long, they are unfortunately 2 weeks out as they are made when ordered and there are several orders for headers ahead of me. I am going to bolt things up tonight and take some accurate measurements. Tomorrow I will go to a local muffler shop I have used before & and see what their confidence is in extending my 11" extensions.

Thanks again, Joe in NH

[mepstein]

If you are not comfortable with your local guy, Ben/MB911 does that stuff all the time.

[joe18d]

I just ordered a set of the correct length street adapters (12 7/8"). One more week of downtime on the lift....

Thanks to all that replied, anyone need a set of 11" adapters?

Joe in NH

[Mahler9th]

Great. Sounds like you are on the right track.