I'm looking at buying a 911 muffler (Dansk) for my six conversion but just curious if the outlet is in the same spot as a stock '73 rear valence. I want to be able to utilize my stock rear valence without modification. If not I might just buy one that has dual outlets like the GT style.

Also, is there any benefit to using a dual outlet versus a single outlet? Would the single outlet be restrictive? My engine is a 3.0, J&E pistons, webcam GE60 and PMO carbs.

Interested to know about this as well....going down the same road.

I have a narrow body 1974 with a 3.2 conversion using the Dansk single outlet mount and the stock rear valance for that perfect sleeper look. It's identical to the rear valance/Dansk muffler arrangement on my '74 LE in measurement.

You have your answer on the valance. I will comment on the GT style.

This is what I have on my 2.7. I love the look, but it is loud. I ended up with baffles in each pipe and that reduced the drone, but the muffler is still loud. ,But, the sound is magnificant. For longer drives I keep ear plugs in the car, and my neighbors are tolerant. Not for the faint of heart...

Here’s what it would look like and it’s super quit. I considered duels but wanted the sleeper look.
Click to view attachment

A 65-73 muffler would be correct a 74 and up 2in 1 out will be off on angle.. A dual outlet would help with flow but for 90% of the engine builds a 2 in 1out is sufficient. Check out my "-6 muffler group buy" thread for how they are constructed internally .

Ben
What are the 10% that required dual outlet? Will your single outlet be good enough for a US spec 3.2?
Dave

The bad ass 3.6 and 3.8 would require it but anything less really doesn't though people think in their minds they do .. Think back to the days of American muscle cars just because a person would go to an open airfilter element didn't mean it went faster it just got louder..

Think about a 3.2 in a 911. The stock exhaust seems less then impressive.. To change to a ssi or something similar improves throttle response but not much else. You will see torque improve a touch.. But most cases they still run a 2in 1out becuase there is nothing to gain with dual outlet but noise..

Keep in mind I am not just speculating as I sold thousands of mufflers with real data points when I owned m&k.

Good to know. I didn’t realize that you had owned M&K.

Yup I started the company and built it up and sold it now about 5 years ago?? Something like that..owned it for 9 years..

Dave - If you ever want to try loud, your welcome to bolt on my M&K 2x2 R muffler. Well, calling it a muffler is a stretch. It's LOUD. It looks awesome. Its a lot of fun. But its not a daily driver and definitely not neighborhood friendly.

I have one of Ben's new 2 in, 1 out, on order.

Funny thing is I just received a dansk GT muffler in the mail for adapting to a set of our 1.625 heat exchangers and wow there is NOTHING inside of it. Just a shell..

I just put baffles I’m my TT Exhusts RSR muffler. Much quieter. Looks like yours. It is notched to clear the 915. 2000-2400 was extremely loud!!I like Ben’s 2 in 1 out, don’t know if it would clear the trans. Drivability is pretty important.

My 2 in 1 out clears the car I tested it on with a 915. Though that said most 915 cars require extra length to the heat exchangers to clear.

For what it is worth, I am running a bone stock 2N1out 911 SC muffler on my 3.0 and it sounds great IMHO at all levels of acceleration. No drone. I had to edit the chrome tail pipe piece to fit precisely in the stock rear valance cut but otherwise, an easy fit and no ear plugs required.

Interesting. I have a M&K 2in / 2 out. The standard version where you can plug up one side and make it a single out. It felt like it gained hp when I un-capped the second port, but your saying its all in my mind? I'm running a carbed/cammed 3.2, about ~280hp at the crank.

You have a really hot engine. 280 is a lot for a 3.2. I bet your car rips.

If you think your gaining 10hp from a second tail pipe Thats just not realistic.. 4-6 maybe but whats that worth?? Drone/dbs? Usually makes it too much for daily driver duty.

Ya it does drone quite a bit from 2-3k, but sounds great above that. I think I am going to install a remote valve so I can have the option to open up the second outlet with a push of a button.

Ya it rips pretty good . I've never dynoed it, but there is the same combo of parts from a guy on pelican and he's at 250hp to the wheels (~290hp at the crank with a 915). It's definitely more power than you need on the street.

http://forums.pelicanparts.com/porsche-911...fore-after.html

Off subject a bit...Forrest did you ditch your 914 style muffler support for the 911 style straps and bracket ? ,thinking of doing that as I already have the stainless straps.

Had a warmed up 3.2 (SSI's, Wong chip, bigger throttle body, sport cams). Ran best and sounded great with a bone stock single outlet Leistritz muffler. Tough to reinvent the wheel sometimes.

I like the stock look better. My car is not flared so without the rear valence it looks odd.

And thats why when developing my new muffler I took the stock muffler apart and just did some minor tweaks and enlarged some of the tubing to increase flow a bit.