Looking for a 2 into 1 for an airhead

[Patsplace]

Any idea where I can get a good quality 2 into 1 system for a 1980 R100?
Pat

[PeoriaMac]

Yeah, MAC sells such a system. You can get it in black ceramic for a few bucks extra. Tucker-Rocky carries it, as do some of the other catalogs.

Google MAC exhausts and you'll get their website.

mac in peoria

[dlearl476]

Originally posted by Patsplace
Any idea where I can get a good quality 2 into 1 system for a 1980 R100?
Pat

I believe Dennis Kirk has them as well.

And apparently you can order them direct:
Mac Exhausts (http://www.mcdistributing.com/index01-BMW.php?model=BMW)

[PeoriaMac]

The MAC exhausts are designed as replacements, not replicas.
...meaning that they do not have the indents on the left hand muffler for the removal of the axle. You'll likely have to take off the muffler to do a tire change.
Also, if you're using stock BMW head pipes and not the MAC headers with a MAC exhaust system, be aware that the length of the muffler is shorter.
That means that the muffler goes farther onto the header than stock...and that the stock two-bolt mounts don't completely match up.
The answer is to use just one of the two bolts on either side.
How secure you are about that depends on you. The alternative is to slide the muffler back...but the muffler/headpipe junction is loose.
Presumably, the MAC headpipes are longer, and compensate for the shorter mufflers.
Be aware that I purchased the MAC headpipes, and could not make them fit. The right side headpipe was bent at the wrong angle..aiming the right muffler right into my Krauser. I contacted MAC by e-mail and never got a response.

As always, YMMV.

Mac in Peoria

[lkchris]

If you have an Airhead that originally was fitted with a two-into-two exhaust, conversion to a two-into-one system will decrease the size of your exhaust system and reduce your power. That crossover (those crossovers) are important and work.

[srb]

my mac 2-into-1 pipe helped my midrange power immensely. you will lose a little bit on the topend going 2-1. topend being 6000 rpm +. i had mine ceramic coated and am pleased with them.

[dlearl476]

Originally posted by Tom McIntyre
The MAC exhausts are designed as replacements, not replicas.
...meaning that they do not have the indents on the left hand muffler for the removal of the axle. You'll likely have to take off the muffler to do a tire change.
Mac in Peoria

Last time I checked, my 2-1 didn't have a left muffler.;)

If you're refering to the 2-2 MUFFLERS they sell:
"OEM replacement items are as quiet as stock. Features include access to all service points, centerstand retention and all metal baffles."
Straight from the horses mouth. This may or may not be true, I don't know. I have a 2-1.

[PeoriaMac]

Sorry, I thought I'd made it clear that I'd purchased the MAC replacement mufflers (two).
As far as "whispertone" goes, they are noticably louder than stock....and while you use the stock mouting bracket...you can only use one (not two) bolt to attach it firmly. As I said, this is with the stock BMW headers. Using the MAC headers might have eliminated that situtation, but I couldn't make their headers work.

Mac