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Akrapovic muffler

30K views 16 replies 7 participants last post by  1poser  
#1 ·
Hi,

Is there any advantage in replacing the OEM muffler with the approved Akrapovic unit (not with the headers, just the can) on a 1200 GS, besides better sound? Any gain in torque and/or power? Not that I'm necessarily looking for more power - heck, I haven't ridden my new GS yet - but I'm curious. And I like the sound, but that's a very expensive mod if all it does is flatter your ears. :)

Thanks.
 
#2 ·
You might get one or extra bhp and lbs-ft but it'll be so insignificant that you won't feel it on the road. The real benefit comes from fitting a set of aftermarket headers without a cat'.
 
#3 ·
Yes, but here, in Quebec, and in Canada in general, they have stringent regulations regarding exhausts, and I'm afraid that solution could be costly in fines. Plus, I would have to install the OEM exahust system back, because I don't think they would regard a subsequent offence with any leniency :eek: Whereas, I think just the can plus cat could be accepted. Then again, I've been arrested on my F800 ST by an officer who proceeded to get on all fours to check my exhaust, and ask for the official government approval tag. Which never existed, by the way. And this was with a perfectly legit OEM system.

How about weight? Will I reduce the bike's weight by 4kgs, as I have seen mentioned somewhere (titanium vs aluminium)? I am 5'7", past my prime, and every ounce here and there counts :eek:

Thank you.
 
#5 ·
Thanks, Schtum. I am sure the roads in Montana are great for biking, as an added bonus. How long do you stop riding in winter?

Actually no, I am not really commited to getting an Akra. There's also the price to factor in. I am evaluating all my mod options, since my brand new bike will be at the dealer's until the end of March, and I want everything decided and carried on before I ride it out of there.
 
#6 ·
Thanks, Schtum. I am sure the roads in Montana are great for biking, as an added bonus. How long do you stop riding in winter?
You mean how long do I stop riding, here in Scotland, during the winter? The Montana thing was a throwaway on the basis of some time SWMBO and I spent there in the summer of '07.

It depends. I've got the point in my life where I pretty much stash the bike in the garage for at least 4 months - November, December, January and February - perhaps more depending upon the weather. However, in years gone by, I have seen me ride in ice and snow. It's about -2 deg C, at the moment, here on the River Forth estuary and there's snow and ice on the sidestreets and sidewalks. Remember that because of our high humidity, it feels much colder than that.

Actually no, I am not really commited to getting an Akra. There's also the price to factor in. I am evaluating all my mod options, since my brand new bike will be at the dealer's until the end of March, and I want everything decided and carried on before I ride it out of there.
So is it a 2010 DOHC bike or a 2009 model? It's worth noting that if you ever were thinking of changing the headers, the new, >'08, bikes have leaner fuelling as stock. For that reason, my '09 GS is currently wearing my Remus Ti exhaust can but I haven't, as yet, fitted my Remus headers which I had on my previous '04 and '07 bikes. If I do fit the headers, I'll also fit the Power Commander which I have and have a custom map made up on the dyno. Some folks seem to think that they can happily fit headers to the later bikes like they did to the earlier one without taking account of the fact that the later bikes are mapped much leaner as stock.
 
#7 · (Edited)
It's a 2009 GS that was on show as promotion by BMW at the dealer's, and they made me a very good price on it fully equipped, ABS, ESA, TPC, panniers, top case... you name it. I just couldn't pass this, even if I wasn't entirely decided to change bike at that moment. Several of my riding buddies ride GS 1200, and they say it's the best bike ever.

We had rotten June and July this year here in Montreal, but fortunately fall was not too bad, and I could ride until the very end of November, which is rare. Last year, we were snowbound by mid-November. I often say «Darn Brits, they ride all year long, through sleet, hail, rain and salt.» But the Scots, apparently not :)

Are you telling me that I would have to change the ignition and fuel mapping if I had an Akra fitted (no headers) on my 09 model? And that I should get a Power Commander? Why is it that leaner fuelling plays havoc with 3rd party cans?
 
#8 ·
Are you telling me that I would have to change the ignition and fuel mapping if I had an Akra fitted (no headers) on my 09 model?
No. Fitting just an aftermarket exhaust can shouldn't upset the fuelling too much.
And that I should get a Power Commander? Why is it that leaner fuelling plays havoc with 3rd party cans?
If you ever fit a set of headers, sans cat', to your bike then, at the very least, you should have the bike run on the dyno to establish that the air/fuel ratios are within safe parameters and be prepared to fit a Power Commander or similar device to enable the fuelling to be mapped back within safe limits if necessary.

It's not that the leaner fuelling plays havoc with aftermarket cans. In fact, cans aren't the issue. However, the later bikes are mapped so lean as standard that fitting freer flowing headers and removing the cat' can raise the throughput of air to a point where it is outside the parameters of the OE fuel map. This causes the bike to run too lean with a consequent risk of engine damage.

HTH
 
#9 ·
I have a '09 GS which I have installed an Akrapovic race exhaust system on. The bike performs noticeably better, the oil temp runs much cooler and the bike isn't as stealth as it was in stock configuration. I felt the stock exhaust was a bit stealth and a bit dangerous when riding amongst traffic. Not everyone looks for or notices someone on a bike, thus I wanted to ensure that someone heard me. Loud Pipes Save Lives :eek:
 
#11 ·
Is there any advantage in replacing the OEM muffler with the approved Akrapovic unit (not with the headers, just the can) on a 1200 GS
Hi Guys, just having a quick trawl through the forums and came across this. I know it's not the most recent thread, but I though I'd clarify what the manufacturer claims for the purpose of future readers...

BMW R1200GS 2004-09

Akrapovic quote:
93.9 HP @ 7200rpm - Stock/Original
95.9 HP @ 7000rpm - Akrapovic, baffle removed, with a peak increase of 3.1 HP @ 6850rpm
4.31 kg's lighter than standard
The sounds measures 87dB - same as standard, but it is deeper and more aggressive

Remus (Hexacone) quote:
99.8 PS @ 7000rpm - Stock/Original
100.8 PS @ 7000rpm - Remus, baffle removed, but there is a considerably larger increase between 5200rpm and 6800rpm.
2.65kg's lighter than standard
Remus do not supply dB ratings for their exhausts, but I know they push the boundaries of road legal limits which is 85dB around 4500 rpm - I'm confident in saying it will have a slightly louder bark then the Akrapovic, but you wouldn't be disappointed by the Akrapovic either!

Cheers
 
#12 · (Edited)
The Akrapovic race system (larger diameter head pipes minus converter and 2 exhaust cans) has an increase of 9 hp and significantly makes the bike louder. I'm not sure what the db is, but it's noticeably louder. Removing the cat from under the sump seems to have decreased the oil temperature, which will definitely prolong the life of the engine and tranny. My bike runs much better, but I notice it pulls harder through redline and it doesn't have the mid range flat spot that it did with the stock system. I felt the bike was too quite with the stock system. With me being from Kentucky, I suppose I may be a Hillbilly or *******, possibly both? I've also noticed that I can go much farther on a tank of fuel than my friend who has a stock muffled bike. The bike seems to do well on fuel consumption unless I'm riding excessively fast on the freeway.
 
#13 ·
My dealer had an R1200GS with the full Akra 2 can system in for service and he fired it up for me to hear. Frankly, I thought it was way to loud.

I am thinking about Remus headers on my '09 R12GS and leaving the stock can on -- to see what that is like. That will get rid of th cat, which will get rid of some weight, heat, but also some back pressure. With aftermarket headers, no cat, and an after market free flowing can, I wonder if the overall reduced back pressure will cause both some performance problems and some potential engine damage (unless other mods are also done such as Power Commander or Booster Plug to enrichen the air to fuel mix back up).

So, maybe a step at a time. Just the Remus headers but leave the OEM can for now. Thoughts?
 
#14 ·
I went with the Remus headers and OEM can. Performance improved. Really smooth, faster revs, no flat spots or peaks, really nice. Sound is no big deal. Still sounds stock (not so great) but a bit louder. I would not do this change for the sound guys but it is worth is from a performance stand point.
 
#15 ·
A friend of mine had the OEM headers (with cat) and an akra single can. He switched headers to some kind of cat-less and then found the akra single can would not fit so he went all the way and installed the akra dual can set up. He likes it but it is loud.

As he has the akra single can just sitting at his home, I asked him if I could try it out on my bike (remus headers). It should fit. Once I try out the remus headers with the akra single can, I will post back.