No customization options are available.

FULL AKRAPOVIC NOW INSTALLED

Discussion in 'Exhaust System & Fuel Delivery' started by James Kennedy, Nov 18, 2017.

  1. James Kennedy

    James Kennedy Active Member

    Messages:
    401
    Likes Received:
    114
    Trophy Points:
    43
    Started with Akras slip on just for the sound. Didn’t think I’d need their headers. I found the bike running out of steam especially in 4th thru 6th over 6 to 6500 rpm’s. Same performance with stock slip on. Decided to add the Titanium Exhaust Manifold to match and see if it helped. WOW, DID IT EVER!!!!!!!! Didn’t have any complaints before but now the bike it so much smoother. Throttle response is much improved and no more running out of steam on the top end. Just wish now that I’d installed Akras full system from the beginning. It is a tad bit louder when the throttle is twisted but just fine cruising. Money well spent. Not concerned about more power so didn’t go with the foam air filter. I just think paper does a much better job removing the fine particulates that cause cylinder wear. For those that have done this is anybody experiencing any lean fueling conditions? I’ve heard the ECU should compensate and at this point I haven’t ridden it far enough to notice. Short ride today but tomorrow I’ll put a couple of hundred miles on her and see how it looks.
     
    ray2, Grumpy Goat and Leon.P. like this.
  2. Grumpy Goat

    Grumpy Goat Well-Known Member Contributor

    Messages:
    3,464
    Likes Received:
    2,059
    Trophy Points:
    113
    This is the only exhaust mod that makes sense to me - full exhaust. Only problem is the cost (US$1700?). Good report, James. I wonder how much hp and torque was gained.
     
    James Kennedy likes this.
  3. James Kennedy

    James Kennedy Active Member

    Messages:
    401
    Likes Received:
    114
    Trophy Points:
    43
    Grumpy, I also was hesitant about the cost but after spending a 200 mile day on it I now wish I’d gone all the way when I cheated out and just installed the slip on. I’ve heard a gain of 13 horsepower but that’s probably with a foam air filter too. I don’t know but I can feel the difference. Pulls now from 2500 to red line with none of that running out of steam above 6K like I felt before. The most amazing thing now is how much smoother the engine is. Anywhere from idle and just off idle the throttle just isn’t as sensitive and jerky. I used to get a bit of a vibration cruising around 5000 rom and that’s also gone. Just smooth, better throttle response, and just stronger. PLUS I just love the sound. I may take it to a specialty shop if my dealer can’t do it but I just want to make sure it’s not running too lean. The exhaust cap looks fine but checking fuel mixture properly is a bit more involved than that. The full Akrapovic will transform your bike
     
    Grumpy Goat likes this.
  4. Peter Burridge

    Peter Burridge Well-Known Member Contributor

    Messages:
    2,736
    Likes Received:
    1,474
    Trophy Points:
    113
    Have you adjusted the fuelling to suit James?
     
  5. James Kennedy

    James Kennedy Active Member

    Messages:
    401
    Likes Received:
    114
    Trophy Points:
    43
    Not yet and she appears to be running just fine. I do plan on having it checked.
     
  6. Peter Burridge

    Peter Burridge Well-Known Member Contributor

    Messages:
    2,736
    Likes Received:
    1,474
    Trophy Points:
    113
    It will. There is a good reason that the likes of KTM sell modified ECUs for this sort of mod. You won't be aware of any damage being done in overheating valves etc. until it's done. Narrow band lambda sensors aren't there to adapt fuelling, contrary to popular myth (at this point somebody normally jumps in and come up with a counter argument - a little research is your friend).

    A good friend recently had his new GS put on a dynamometer to set up a Power Commander to match his full system. Not only does it preserve the thermal integrity of your engine it also liberates the performance the full system should be giving you.

    The reason I don't remove my Remus baffle is because I don't have modified fuelling, that and I don't really need the noise. I did have a full Remus on my 2004 GS and used a Techlusion fuelling unit that although a bit of a work around made a huge difference.
     
    Last edited: Nov 19, 2017
    James Kennedy likes this.
  7. James Kennedy

    James Kennedy Active Member

    Messages:
    401
    Likes Received:
    114
    Trophy Points:
    43
    Thanks for the information. Much appreciated. The bike does run a lot smoother and pulls like it’s supposed to now. I have a shop in mind I’m going to take her to for further analysis.
     
    Peter Burridge likes this.
  8. Peter Burridge

    Peter Burridge Well-Known Member Contributor

    Messages:
    2,736
    Likes Received:
    1,474
    Trophy Points:
    113
    I’m not trying to be negative James. Peter
     
    James Kennedy likes this.
  9. James Kennedy

    James Kennedy Active Member

    Messages:
    401
    Likes Received:
    114
    Trophy Points:
    43
    I didn’t take it that way at all Peter. Unless my bike does compensate there is always the real concern of damaging the exhaust when opening up the exhaust the way I did. I’ve already made contact with a Guy locally who can asses the bikes performance and add a fuel controller if need be. This is a road I didn’t really want to go down with fuel controllers and such but after opening up the exhaust and experience the difference I’d do it again. My bike was really running out of steam in the upper power band before. Pulling in 4th thru 6th above 6K felt like I had a head wind and a slight uphill. That sensation is gone. Riding in traffic in 1st just off idle is way different with the throttle response. Just way smoother. It really transformed the smoothness and response of the engine. I did originally add the slip on for the sound. Not too loud but really a nice tone. Installing the new header added some volume but not over the top or annoying though at all.
    I’m not sure how they determine whether or not the fuel mixture is too lean but he has a dyno and I guess I’m going to find out.
    I’ll never know now but it’s possible that exhaust valve (flapper) wasn’t opening up all the way. I haven’t really heard of anyone else complaining about this issue.
     
  10. SauRoN

    SauRoN Well-Known Member

    Messages:
    994
    Likes Received:
    412
    Trophy Points:
    63
    I wonder if just knocking the cat out of the stock exhaust wouldn't amount to much the same really.
     
  11. Peter Burridge

    Peter Burridge Well-Known Member Contributor

    Messages:
    2,736
    Likes Received:
    1,474
    Trophy Points:
    113
    I can understand the resistance to add a piggyback fuel controller. It's not the perfect solution but barring the ability to change out or remap the ECU it's the best there is. The dyno guy will be able to sort you out if he's worth his salt. It'll be interesting to see the outcome and any performance benefits you reap.

    Cat's are hugely restrictive. I removed the one on my VFR1200 and added a Two Brothers can. Dynojet HQ in the UK are just down the road from me and they did a dyno run and set up the Power Commander. It gave me 161 rear wheel hp. My friends VFR gave out 167 and it had more miles in it's engine. The performance increase was pretty phenomenal and it became a missile. A missile with suspension that couldn't cope.
     
    James Kennedy likes this.
  12. James Kennedy

    James Kennedy Active Member

    Messages:
    401
    Likes Received:
    114
    Trophy Points:
    43
    Going in for a dyno tomorrow to make sure everything is ok. Which I hope it it. Don’t really like the idea of having to add extra stuff to the bike like fuel controllers. Just like to keep it simple. I’ll let you know the results.
     
    Peter Burridge likes this.
  13. Peter Burridge

    Peter Burridge Well-Known Member Contributor

    Messages:
    2,736
    Likes Received:
    1,474
    Trophy Points:
    113
    It'll be worth checking and I understand your feelings on the PC.

    The Lambda sensor fitted to our bikes is a narrow band sensor only. It works like a simple switch and only affects the ECU when the bike is in 'closed loop mode'. In this mode, that only occurs in a certain narrow set of circumstances, the sensor switches the fuelling between two set points in order to maintain a narrow band of air/fuel ratio for emissions testing purposes. Some bikes 'hunt' at certain steady state riding conditions, particularly in a low gear. That is the effect of the switching on the engine drive. The RS does do it but it's mild and I rarely find myself in those revs/gear combination in a steady state.

    To assume that the sensor somehow compensates for modified exhaust systems is folly but these tales abound even in places where folk should know better.

    Peter
     
    James Kennedy and duccrazydave like this.
  14. SauRoN

    SauRoN Well-Known Member

    Messages:
    994
    Likes Received:
    412
    Trophy Points:
    63
    Is it a bit strange that BMW fully support the Akra + Headers under warranty and don't offer a BMW approved ECU map to go with it.

    Unless they believe it is already just fine for the stock setup?
     
    Grumpy Goat and Peter Burridge like this.
  15. Peter Burridge

    Peter Burridge Well-Known Member Contributor

    Messages:
    2,736
    Likes Received:
    1,474
    Trophy Points:
    113
    I know they approve the can but I wasn't aware that the headers were 'officially' supported. Some dealerships will say yes (especially if they make money) but that isn't the same thing methinks. Any thermal damage is likely to occur 'down the line' not straight away.
     
  16. Scorch

    Scorch Well-Known Member

    Messages:
    766
    Likes Received:
    479
    Trophy Points:
    63
    I've been told by a number of different sources that Akrapovic are nowadays considered to be an OEM part when it comes to BMW.
    I had this argument with the BMW extended warranty people when my Akrapovic-equipped F800ST went to extended warranty after 3 years, and I got letters from my dealership to this effect, which satisfied them.
     
    Peter Burridge likes this.
  17. Fjaoos

    Fjaoos Member

    Messages:
    29
    Likes Received:
    26
    Trophy Points:
    13
    Is the Akrapovic system even street legal? I can't find any source that says this...
     
    Peter Burridge likes this.
  18. Peter Burridge

    Peter Burridge Well-Known Member Contributor

    Messages:
    2,736
    Likes Received:
    1,474
    Trophy Points:
    113
    I've been told by a number of different sources

    Therein, with respect, lies the rub.

    I suppose it comes down to personal judgement. I've not seen an official BMW Factory sanction for running a full open system with a standard ECU, no piggyback unit or mods. The existing fuelling system isn't designed to adapt. The engine will be thermally stressed to a greater extent due to a leaner mixture in a modern engine designed to run lean anyway. Now whether this impacts on the long term reliability or not, or how the probability of failure is increased I don't know. It may be entirely insignificant.

    I do know that I wouldn't do it myself. I'm a retired professional engineer with an early background in the motor vehicle industry so I'm not an engineering dummy but I may be over cautious.

    Peter
     
  19. Peter Burridge

    Peter Burridge Well-Known Member Contributor

    Messages:
    2,736
    Likes Received:
    1,474
    Trophy Points:
    113
    In terms of decibels, at least in the UK answer is that nobody seems to bother enforcing any legislation. You certainly won't get into a Cadwell Park track day :D
     
    Scorch likes this.
  20. Scorch

    Scorch Well-Known Member

    Messages:
    766
    Likes Received:
    479
    Trophy Points:
    63
    If the exhaust is CE stamped and still carries its DB Killer, then it is road legal.
    But even without the DB Killer, you're unlikely to get done for it, unless get stopped for something else and then you fail the 'attitude test', and the officer starts looking for more stuff to add to your woes... ;)
     
    Peter Burridge likes this.

Share This Page