Experiences with full Akrapovič system on LC

Schtum

Schtum

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I know there are a few folks on here who have or have had full systems on their LC's. So would you care to share your experiences of performance, sound levels, fuel consumption and anything else relevant?

I've had an Akrapovič can on my late 2013 bike from new. I bought a set of headers on here late last year and only started riding the bike, with them fitted, quickly, this week and particularly yesterday after I'd been for an MOT. I've obviously got a bit detuned with riding my XCountry recently but my first impressions are that the Akrapovič headers have made a big difference to how the bike goes. In Dynamic mode it takes off like a stabbed rat with little more than a tickle of the throttle, all the time making a sound like tearing calico.

I've yet to have the fuelling adjusted and a quick run on the local dyno revealed that it's much too lean. However, it's popping on gearchanges and spitting flame. The sound and throttle response is a bit addictive which, no doubt, goes some way to explaining the loss of some 9 - 10 mpg. Today's average was 41 mpg. Overall the character of the bike is much less bland than before, even although I still have the baffles in the can. I've experienced this before when I fitted a full Remus system to two of my previous GSes but there probably wasn't such a perceived uplift in performance.

(Pic courtesy of Ghiribizzo)
 

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I had the full system on my last LC1200 - and loved it!
As you say - it was 'highly addictive'. The sound and feel was a big jump from the standard bike.
I don't have any performance figures as this was never important to me - but the grin factor was huge.
When I test rode the new 1250 with a standard system, it felt pretty bland by comparison - although I could feel the extra power it offered.
So in context - I would not have swapped my LC1200 with the full system for the new 1250 without.
In short, in my opinion - its highly recommended!
:beerjug:
 
gateway77 said:
I had the full system on my last LC1200 - and loved it!
As you say - it was 'highly addictive'. The sound and feel was a big jump from the standard bike.
I don't have any performance figures as this was never important to me - but the grin factor was huge.
When I test rode the new 1250 with a standard system, it felt pretty bland by comparison - although I could feel the extra power it offered.
So in context - I would not have swapped my LC1200 with the full system for the new 1250 without.
In short, in my opinion - its highly recommended!
:beerjug:
Click to expand...

I experienced the complete opposite
 
The GS is set up very lean from the factory and removing back pressure from the exhaust doesn't help.
Adding an end can only adds noise, putting on the decat headers definitely smoothes things out and adds even more noise.
For your bike to have a big drop in mpg is unusual, some of this is no doubt due your enjoying the exhaust note. Considering that all GSs should be made the same, they do seem to vary on their fueling, yours seems to be at the extra lean end of the scale.
You need to get the bike remapped, there are different ways of doing this, the easiest is Hilltop, ride in ride out, bike transformed.
I think the best set up is decat headers, stock endcan and a remap. You get a deeper tone without it offensive or tedious on long journeys and the remap sweetens the whole thing.
 
CPJS said:
The GS is set up very lean from the factory and removing back pressure from the exhaust doesn't help.
Adding an end can only adds noise, putting on the decat headers definitely smoothes things out and adds even more noise.
For your bike to have a big drop in mpg is unusual, some of this is no doubt due your enjoying the exhaust note. Considering that all GSs should be made the same, they do seem to vary on their fueling, yours seems to be at the extra lean end of the scale.
You need to get the bike remapped, there are different ways of doing this, the easiest is Hilltop, ride in ride out, bike transformed.
I think the best set up is decat headers, stock endcan and a remap. You get a deeper tone without it offensive or tedious on long journeys and the remap sweetens the whole thing.
Click to expand...


The bike is set up from the factory to run in compliance with EU emission regulations. This means that the fueling is kept on the lean side, but not lean to the extent of harming the engine. The fueling is continuously monitored by the O2 sensors, thus if your engine starts drawing false air, the fuel mixture will be adjusted on the fly to ensure the correct mixture of air/fuel. This is to comply with the emission regulations, but also benefits the engine as it will never run excessively lean or rich. This also means that whatever can you put on, as long as the O2 sensors are connected, the bike will adapt to the requirements in order to obtain proper fueling.

For the BMWs, adaptive systems have been present since they introduced the O2 sensors back in the early -90's. After that, a remap would be useless unless you disconnect the O2 sensors (and at the same time introduce other issues).

As for HT, they don't remap. The have rewritten the management part of the software. (according to their own information)
 
Here’s my two pennies worth. I have a full akro on my LC and my mate at the time had a full stock system on his. We both went for a hilltop tune, without mapping (or whatever you want to call it) the stock exhaust bike made more power at the top end.
Now after the remap both bikes made the same peak power and same peak torque, the advantage of the akro was a smoother torque curve with more torque at the bottom end, what the bike produced as maximum torque before the remap was now being produced at 2000rpm instead of 5500rpm and there was 25% more at 5500rpm. You also loose the heat from the cat and it sounds awesome without being to noisy, before the remap it did sound tinny and course. I love the way it makes power, far better than a 1250 does. The only downsides I can see are the costs and fault codes for the flap and sensors, but they don’t show on the dash and only can be viewed via a GS-911 or the dealer, most dealers are aware of hilltop remaps and just ignore it. I wouldn’t put mine back to stock, it’s just so nice to ride and sounds fantastic.
 
GB. said:
HereÂ’s my two pennies worth. I have a full akro on my LC and my mate at the time had a full stock system on his. We both went for a hilltop tune, without mapping (or whatever you want to call it) the stock exhaust bike made more power at the top end.
Now after the remap both bikes made the same peak power and same peak torque, the advantage of the akro was a smoother torque curve with more torque at the bottom end, what the bike produced as maximum torque before the remap was now being produced at 2000rpm instead of 5500rpm and there was 25% more at 5500rpm. You also loose the heat from the cat and it sounds awesome without being to noisy, before the remap it did sound tinny and course. I love the way it makes power, far better than a 1250 does. The only downsides I can see are the costs and fault codes for the flap and sensors, but they donÂ’t show on the dash and only can be viewed via a GS-911 or the dealer, most dealers are aware of hilltop remaps and just ignore it. I wouldnÂ’t put mine back to stock, itÂ’s just so nice to ride and sounds fantastic.
Click to expand...

Quote Hilltops website:

We call ourselves 'remappers' because that is the colloquial term that everyone understands, but actually we write engine management software. This is much more complex, time-consuming work but means we have several advantages over conventional remappers:


From Acrapovics website BMW R1200GS LC:
----------------------------Unit-----------------Stock -------------------- Akrapovic ------------------- Max gain
Maximum power_____kW____________ 86.9 / 8000 rpm _____89.1 / 8000 rpm________+ 2.6 / 7300 rpm

___________________HP (m)_________118.2 / 8000 rpm ____121.1 / 8000 rpm_______+ 3.5 / 7300 rpm

___________________HP (i)__________116.6 / 8000 rpm_____119.4 / 8000 rpm_______+ 3.4 / 7300 rpm

Maximum torque______Nm___________116.6 / 6500 rpm_____118.4 / 6650 rpm_______+ 4.2 / 4800 rpm


According to Acrapovic, these are the numbers gained when adding their complete system to the 1200GS LC.

One may wonder why they publish such modest numbers, trying to promote their stuff, when som shack is able to convert the engine to virtually an afterburner….


Making a hell of a racket may thrill the rider, but does very little to the rear wheel… But hey, what does Acrapovic know….
 
Running a full akro system without altering the fuelling your bike will produce less power. Whether someone who could do a specific map for my bike would give it more power and torque than the self learning generic map hilltop uses I’ll never know but I think that may be the case.
 
GB. said:
Running a full akro system without altering the fuelling your bike will produce less power. Whether someone who could do a specific map for my bike would give it more power and torque than the self learning generic map hilltop uses I’ll never know but I think that may be the case.
Click to expand...


I respect your opinion. But I did not express my opinion. I told you how it is. This is how the BMW ECUs are programmed, and have been programmed for the last 25 + years.
Ignoring the facts may be more fun, but it does not change the facts.
 
GB. said:
what the bike produced as maximum torque before the remap was now being produced at 2000rpm instead of 5500rpm and there was 25% more at 5500rpm.
Click to expand...

Do you really believe it now produces max torque at 2,000rpm - taking aside the 25% extra claim?
 
Sorry you have totally lost me, all I have are dyno figure facts, ok they are from hilltop but both bikes were on the same dyno, I don’t understand what you are trying to say?
 
I'm sure I should have anticipated the comments about fuelling. The bike's booked into Motorrad Central in Dalkeith on Thursday to be Hilltopped.

knutk said:
This also means that whatever can you put on, as long as the O2 sensors are connected, the bike will adapt to the requirements in order to obtain proper fueling.
Click to expand...

Not quite Knut and I'm sure this has been done to death. It will only do this when it's running in closed loop mode. To do what you suggest would necessitate a pair of wideband lambda sensors and an ECU programed to suit.

As for the flap valve in the exhaust, I've removed it completely and fitted a Servo Buddy which eliminates and fault codes. https://www.speedycom.co.uk/shop/product.php?productid=19880
 
Mr Bean said:
Do you really believe it now produces max torque at 2,000rpm - taking aside the 25% extra claim?
Click to expand...

You misunderstood, what it used to make at 5500rpm it now makes at 2000rpm and it makes 20-25% more than it did at 5500, max is now at the 5500 mark
 
GB. said:
You misunderstood, what it used to make at 5500rpm it now makes at 2000rpm and it makes 20-25% more than it did at 5500, max is now at the 5500 mark
Click to expand...

Ah, apologies on that.

I still doubt the numbers as I don't believe it would be possible on a naturally aspirated engine.
 
GB. said:
Running a full akro system without altering the fuelling your bike will produce less power. Whether someone who could do a specific map for my bike would give it more power and torque than the self learning generic map hilltop uses I’ll never know but I think that may be the case.
Click to expand...

I can appreciate it wouldn’t really make more power but less??
With the closed loop (yes it’s not in closed loop all the time but the majority of the time it is for most riders - apart from a few of our resident lunatics)
Akrapovic wouldn’t put figures down on paper if it made less and instead use nice vague marketing type phrases.
 
I can only tell you what we found, my bike is also not a Euro 4 model like my mates was. It was peak power where it lost out, just to lean. The throttle response is much better with the akro that I do know.
 
Schtum said:
Not quite Knut and I'm sure this has been done to death. It will only do this when it's running in closed loop mode. To do what you suggest would necessitate a pair of wideband lambda sensors and an ECU programed to suit.

As for the flap valve in the exhaust, I've removed it completely and fitted a Servo Buddy which eliminates and fault codes. https://www.speedycom.co.uk/shop/product.php?productid=19880
Click to expand...

Well, the thing is, here is where the adaptive map comes in. So, even in open loop conditions the engine will get the correct fuel.

I don't mind if you guys spend your money on whatever you feel like. Usually, the money spent in the least sensibel way is what brings the most fun. If that means HT and Acra, I see it no worse than anything else.
My point is though, that doing it because rhe engine needs it is plain wrong. The engine is fully capable of taking care of the fueling on its own.

As for the fabelous numbers of gain in any parameter provided by HT, I find it odd that the fact that HTs after numbers corsponds to any other test of the LC engine without the HT treatment, and that the before graphs provided by HT are way lower than measured by any one else. Surely this must ring a bell?
 
Here’s the deal, my bike is better after having the fuel altered than it was before, end of.
 
knutk said:
My point is though, that doing it because rhe engine needs it is plain wrong. The engine is fully capable of taking care of the fueling on its own.
Click to expand...

I had the bike run on the dyno a couple of weeks ago with the full system fitted. We were seeing AFR's or c. 15:1. Too lean I think.
 
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