Which Akrapovic?

[GS Bloke]

Hi
I see that there’s 2 options of Akrapovic for the GS1250, the BMW branded and the standard Akrapovic, they are a totally different design and I prefer the non BMW version but I have acquired the BMW one on the cheap.
So do I keep the BMW one and save a chunk of money despite there being no published performance figures and it’s heavier than the OEM tail pipe, or sell it and buy the non BMW Akrapovic system which is lighter and does have performance claims and maybe slightly louder.
Has anyone have experience of both systems?
Thanks

 

[Victor c]

Hi
I see that there’s 2 options of Akrapovic for the GS1250, the BMW branded and the standard Akrapovic, they are a totally different design and I prefer the non BMW version but I have acquired the BMW one on the cheap.
So do I keep the BMW one and save a chunk of money despite there being no published performance figures and it’s heavier than the OEM tail pipe, or sell it and buy the non BMW Akrapovic system which is lighter and does have performance claims and maybe slightly louder.
Has anyone have experience of both systems?
Thanks

I have the BMW Akro end can on my gsa and it is really just an expensive trinket. It adds a tiny bit more sound, but nothing worth writing home about. If you do change to a standard Akro, just keep an eye on your number plate, as they can run hotter and melt it.

 

[Nick dj]

I bought a Cobra off this site to try.
Its within 1 db of standard but sounds nicer esp on full throttle.
Its mounted on a carbon hanger and seemed to cut vibration in my righthand foot peg.
Its 5/6 lighter and makes a difference.
The Carbon and titanium are all better quality than the Akro and half the price.

 

[Brian O]

a question for those in the know,

if you were to fit either of these as a replacement for the standard exhaust can on a 1250 gsa does anything need to be done to the fueling, ecu etc.

thank you

 

[siddo]

a question for those in the know,

if you were to fit either of these as a replacement for the standard exhaust can on a 1250 gsa does anything need to be done to the fueling, ecu etc.

thank you

No.

 

[Spook1969]

End cans are generally plug and play, when you change the headers then you need a remap or fueling module

 

[siddo]

End cans are generally plug and play, when you change the headers then you need a remap or fueling module

I didn't. Mine runs great.

 

[Buttertub]

If i was you i'd not bother with performance issues/charts as if there is any actual difference it'll be almost impossible to tell when your in the saddle.

if its made by Akro and you definitely want to know 100% I'd just ask em. I'd take the view its nothing but a special run for the BMW money making machine with a slightly different design to justify it i.e same performance as the non BMW as I wouldn't want to put my companies name on something that doesn't deliver. Just my take anyways.

If its looks then thats different, i'd fit it, see if it grows on you and then decide. Easy enough to get your money back because of its badge. I've got the euro 3 akro (black) version that fits the 1200/1250 they come up on here on occasions, removable baffles but its got a nice enough sound with them in anyways. Keep an eye open on here if its bothering you in 6 months.

 

[ProdigalGS]

I bought a Cobra off this site to try.
Its within 1 db of standard but sounds nicer esp on full throttle.
Its mounted on a carbon hanger and seemed to cut vibration in my righthand foot peg.
Its 5/6 lighter and makes a difference.
The Carbon and titanium are all better quality than the Akro and half the price.View attachment 534802

The silencer is likely to move backwards and forwards inside the carbon hanger as the exhaust heats up and cools down. Akrapovic used to make exhausts like this and the result was lots of local scratching from the relative hanger movement. I had this on an earlier GS. The newer Akrapovic exhausts have a hanger welded onto the silencer and expansion is catered for by the oval shape inside the attachment bush. I hope this doesn't happen to you as removing scratches from titanium is not easy.

I would not agree that Akrapovic quality is inferior to Cobra but that's a judgment call. I have an full Akra system on my 1200 (titanium silencer and stainless de-cat headers) and am delighted with it. I wouldn't dream of paying £900-1,000 for a new Akra silencer but an immaculate used one for half the price is muxh more appealing.

 

[Nick dj]

The silencer is likely to move backwards and forwards inside the carbon hanger as the exhaust heats up and cools down. Akrapovic used to make exhausts like this and the result was lots of local scratching from the relative hanger movement. I

No movement appears to have happened at all (over 25K on two bikes)- doubt the end can expands much and its connection to the pipe is two springs, so the expansion may happen there.

 

[Dezi58]

The silencer is likely to move backwards and forwards inside the carbon hanger as the exhaust heats up and cools down. Akrapovic used to make exhausts like this and the result was lots of local scratching from the relative hanger movement. I had this on an earlier GS. The newer Akrapovic exhausts have a hanger welded onto the silencer and expansion is catered for by the oval shape inside the attachment bush. I hope this doesn't happen to you as removing scratches from titanium is not easy.

I would not agree that Akrapovic quality is inferior to Cobra but that's a judgment call. I have a full Akra system on my 1200 (titanium silencer and stainless de-cat headers) and am delighted with it. I wouldn't dream of paying £900-1,000 for a new Akra silencer but an immaculate used one for half the price is muxh more appealing.

wrt de-catting your 1200, are you happy with the results simply because the bike feels “better” or did you arrange a rolling road test before and after fitting the new headers / end can in order to see what and where the improvements were achieved? I’ve 1200 Rallye and was planning the same mod however I’ve been advised by a race engine / performance company that changing the headers brings almost nothing and just to buy a good quality end can and they’ll map the engine from rolling road testing it. They did mention isolating the butterfly valve and disconnecting the O2 sensors would be considered.

 

[siddo]

wrt de-catting your 1200, are you happy with the results simply because the bike feels “better” or did you arrange a rolling road test before and after fitting the new headers / end can in order to see what and where the improvements were achieved? I’ve 1200 Rallye and was planning the same mod however I’ve been advised by a race engine / performance company that changing the headers brings almost nothing and just to buy a good quality end can and they’ll map the engine from rolling road testing it. They did mention isolating the butterfly valve and disconnecting the O2 sensors would be considered.

Sounds like they are talking nonsense. Decatting and removing the flap makes it flow better and will improve performance. Changing the can will only achieve weight saving.
I noticed improved throttle response and better acceleration by decatting and flap removal. After warranty expires I may go for end pipe, DNA filter and remap.

 

[Dezi58]

Sounds like they are talking nonsense. Decatting and removing the flap makes it flow better and will improve performance. Changing the can will only achieve weight saving.
I noticed improved throttle response and better acceleration by decatting and flap removal. After warranty expires I may go for end pipe, DNA filter and remap.

Perhaps you need to read it again, they said disconnecting the O2 sensors and flap valve would be considered (as part of the tuning process) in other words dyno test the engine on their rolling road with or without and see if it made any difference. They did warn not to expect significant improvements just a general overall refinement. They were against removing the stock headers as they had experienced significant problems with after market headers on other makes of bikes but as race bike engine builders / tuners they didn’t have a lot of data on GS’s but advised against header removal in the first instance. Wrt to your comments, you said you’ve removed the cat and flap valve
(and by default the O2 sensors) but somehow don’t consider this to be outside the terms of the warranty, might want to check with BMW on that Mr

 

[OMG!!]

Get yourself a Delkevic carbon fibre covered exhaust, road legal, no modifications required, slip on tighten down and go, much lighter than standard exhausts much cheaper than Akro's, those akro's are just a fad everyone wants one, whole load of money for a slightly different noise.
Great thing about carbon covered exhausts, less heat on the can than on any stainless steel one, less chance of burning someone leg, or your own.

https://www.ebay.co.uk/itm/298018902977?

 

[siddo]

Perhaps you need to read it again, they said disconnecting the O2 sensors and flap valve would be considered (as part of the tuning process) in other words dyno test the engine on their rolling road with or without and see if it made any difference. They did warn not to expect significant improvements just a general overall refinement. They were against removing the stock headers as they had experienced significant problems with after market headers on other makes of bikes but as race bike engine builders / tuners they didn’t have a lot of data on GS’s but advised against header removal in the first instance. Wrt to your comments, you said you’ve removed the cat and flap valve
(and by default the O2 sensors) but somehow don’t consider this to be outside the terms of the warranty, might want to check with BMW on that Mr

No, O2 sensors are reinstalled in the Black Widow.

 

[Dezi58]

Get yourself a Delkevic carbon fibre covered exhaust, road legal, no modifications required, slip on tighten down and go, much lighter than standard exhausts much cheaper than Akro's, those akro's are just a fad everyone wants one, whole load of money for a slightly different noise.
Great thing about carbon covered exhausts, less heat on the can than on any stainless steel one, less chance of burning someone leg, or your own.

https://www.ebay.co.uk/itm/298018902977?

Ive used delkevic several times and found their quality very good (as are GR Moto silencers) can’t justify the cost difference of Akro’s especially not considering out and out performance is not exactly a priority on huge adventure bikes

 

[Dezi58]

No, O2 sensors are reinstalled in the Black Widow.

I know but the make of headers wasn’t mentioned (at least not that I noticed) however, that wasn’t the point which was the implications to the manufacturer’s warranty of removing headers and flap valves etc

 

[Nick Marshall]

Instead of buying budget Delvic etc. have you spotted the one on eBay?

https://www.ebay.co.uk/itm/377492919618

Oops it’s been sold.

 

[ProdigalGS]

wrt de-catting your 1200, are you happy with the results simply because the bike feels “better” or did you arrange a rolling road test before and after fitting the new headers / end can in order to see what and where the improvements were achieved? I’ve 1200 Rallye and was planning the same mod however I’ve been advised by a race engine / performance company that changing the headers brings almost nothing and just to buy a good quality end can and they’ll map the engine from rolling road testing it. They did mention isolating the butterfly valve and disconnecting the O2 sensors would be considered.

I didn't do a before and after dyno test because that would have been both expensive and inconvenient. My initial motivation was to get rid of the standard headers as the valve had seized. I decided on the Akra headers in stainless - more robust than titanium - and then went the whole hog with a servo buddy and Hilltop remap. It doesn't really need the servo emulator but they're not expensive and it avoids having an exposed connector where it is bound to corrode.

The bike doesn't just feel better, it is materially faster. It pulls from below 2,000rpm and the acceleration in 6th at 50/60mph is stronger, less need to change down. The surprise is that it is much more economical unless you are caning it. I got high 40s riding from London to Leicester and mid-50s going home. It delivered 65mpg on a recent road trip with a mix of motorway and A-roads. I'm going on a trip soon with a mate with a new R1300GS, it will be interesting to swap bikes and do a direct comparison. I rode a 1300 in Romania and it felt no faster than my 1200 and was less happy trickling through town at 2,000rpm.

I have had lots of GS's and I have had other bikes remapped too. This remap was the best I have ever experienced.

Regarding the advice from your race engine company, that sounds very....odd. Removing the cat and valve, and adding larger diameter headers with better gasflow will do much more than changing the silencer. And removing the O2 sensors means that the ECU has no way of knowing how the engine is running.

 

[Schtum]

I didn't do a before and after dyno test because that would have been both expensive and inconvenient. My initial motivation was to get rid of the standard headers as the valve had seized. I decided on the Akra headers in stainless - more robust than titanium - and then went the whole hog with a servo buddy and Hilltop remap. It doesn't really need the servo emulator but they're not expensive and it avoids having an exposed connector where it is bound to corrode.

The bike doesn't just feel better, it is materially faster. It pulls from below 2,000rpm and the acceleration in 6th at 50/60mph is stronger, less need to change down. The surprise is that it is much more economical unless you are caning it. I got high 40s riding from London to Leicester and mid-50s going home. It delivered 65mpg on a recent road trip with a mix of motorway and A-roads. I'm going on a trip soon with a mate with a new R1300GS, it will be interesting to swap bikes and do a direct comparison. I rode a 1300 in Romania and it felt no faster than my 1200 and was less happy trickling through town at 2,000rpm.

I have had lots of GS's and I have had other bikes remapped too. This remap was the best I have ever experienced.

Regarding the advice from your race engine company, that sounds very....odd. Removing the cat and valve, and adding larger diameter headers with better gasflow will do much more than changing the silencer. And removing the O2 sensors means that the ECU has no way of knowing how the engine is running.

I have exactly the same mods on my 2013 which has the lighter flywheel and spins up a bit quicker than the later bikes. It pulls like a train and fuels beautifully in all modes