GC6269
Registered user
Bloody hell. That's another 400 notes gone from the bonus!!!
acrapovic headers
- Thread starter old gixer boy
- Start date
Yes!
And I preferred the look of the Remus over the Akro (IMHO cleaner with less visible welds)!
Either way you go you'll notice the difference and you get a Brucie bonus in that they sound very nice too!
So, what's better, Akra headers, or a remap, if you had to choose one or the other? I understand that the remap irons out the flat spots, and from the sound of it, so do the Akra headers. So which is the better option, and what are the differences?
Rich, Aftermarket exhaust modifications fall into two categories: full systems and slip-ons. The full systems replaces the entire stock system. The akra headers have various tapers and a crossover to enhance low- and midrange torque after removing the exhaust valve while still improving top-end power. In fact, some systems offer minimal gains in peak power, choosing to instead shape the power curve for more midrange and a broader horsepower peak.
However, one possible disadvantage of many aftermarket systems for the gs is that they require the removal of the servo-controlled valve that some OE exhausts use for better low-end power and your allowing the gases to flow without restrictions and in stock it already runs lean so a remap would probably be your nxt point of call after fitting the full system.
Gain wise, for stock bike a remap with standard exhaust would iron out the fuelling issues making it much smoother, however if at a later stage you wanted headers, than you would have to have the map tweaked to take into account the new headers, having just the headers and no remap would mess with the stock fuelling and make it less efficient and probably more lean.
I may be talking bollox tho !
GC6269
Registered user
I think these days exhausts valves are there to pass noise regulations than to enhance low end power.
Yep, that's my understanding too, based on a conversation with my trusted BMW mechanic at Bahnstormer. The flap is only there to quieten the bike at low speeds in town and has little impact on either power or fuelling.
Apparently no change to mapping is needed with either the Akra or Remus full road systems, unless you also fit a free flow filter.
My riding experience to date has been improved throttle response and mid-range with no issues on fuelling. I guess time and more miles will provide more of a test though.
Well the flapper valve question was just settled in the latest Motorcyclist issue.
Aaron Frank reported a loss of 3-5 lb-ft between 2750 and 4500 rpm with the exhaust valve removed.
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- from http://www.advrider.com/forums/showthread.php?t=891023&page=111
Aaron Frank reported a loss of 3-5 lb-ft between 2750 and 4500 rpm with the exhaust valve removed.
.
- from http://www.advrider.com/forums/showthread.php?t=891023&page=111
Can't find the article through your link or a quick search. I'll try harder later when I'm not looking after my one year old
In the meantime here's the literature on this from Nippy which seems to directly contradict this:
Remus conical headers
Performance
When fitted with the Akrapovic silencer the power increase is 8bhp (baffle out) and 6.5bhp with baffle in.
This figure is peak power, but does not explain the surge in mid-range power gained. There is a MASSIVE increase in torque between 3,500 and 5,500 rpm.
The increase at 5,000 is 12% more torque than standard from 88nm to 99nm
Fitting the collectors alone with the OE silencer will give about 3-4hp gain
No other modifications to the carburration are necessary when fitting these collectors.
I suspect some will find this enough, some will want more evidence. As for me I'm very happy with the set up
Tbh i would not believe that statement from NN site, reason why he prints the same bollox giving the same gains on all aftermarket headers for all bikes not just the wc. My TC ran a full race akro and without any mapping it actually lost power over the stock system, its a sales pitch im sure you would not buy if it said fitting these, your bike may need mapping to get full benefit as it could lose power over stock ! the Dyno does'nt lie and the seat ov me pants tells me the rest !
Yes, and if I had bought a full race system I would definitely be getting a re-map as that is pretty standard practice (which I've done before on previous race bikes). This, however is a road system, and the seat of my pants is currently telling me it's running sweetly with noticeable gains and smooth response in the mid-range. If that changes then I'll let folk know on here and go get myself a re-map. Right now I'm a happy bunny and from my own experience (albeit limited n=1 study) would recommend a full Akro or Remus system to anyone who is thinking of going down this route.
Yes but if you take the baffle out your road system it than becomes a race system and as the NN site states no adjustment to fueling is necessary, i totally disagree, if you want to see full benefit, regardless if baffles in/out than its a remap following fitting the system.
Just like this system on my TC
Marked as race only because of the non baffles, however I made some baffles, and it mapped better with baffles fitted than without, by having baffles fitted it also moved its peak power to a different rpm range I was chasing torque figures so lowering it down the rpm range was perfect, bhp don't float my boat I want a smooth, torquey motor.
Just like this system on my TC
Marked as race only because of the non baffles, however I made some baffles, and it mapped better with baffles fitted than without, by having baffles fitted it also moved its peak power to a different rpm range
I was chasing torque figures so lowering it down the rpm range was perfect, bhp don't float my boat I want a smooth, torquey motor.Usurp66
Registered user
I would tend to agree, I'm using the Remus headers with the standard end can, runs very smoothly and although it has not been on a dyno I would suggest that there are no lean running issues as plug colour is perfect. Definitely feels more responsive and generally fitter in the midrange, much as my old GSA did with the same set up. Probably as much to do with eliminating the catalytic converter as anything else imho.
Perhaps this might help clarify further: http://www.nippynormans.com/products/akrapovic-and-remus
And same thing on both Akro and Remus websites.
So it would seem it's fine to just take them out the box and "plug and play" with either dB killer in or out and not worry about a remap or running lean. For those who want further improvement a trip to the nearest "chippy" for a bit of re-programming will deliver additional benefit.
Like most things motorcycle related "you pays your money and takes your choice"
And same thing on both Akro and Remus websites.
So it would seem it's fine to just take them out the box and "plug and play" with either dB killer in or out and not worry about a remap or running lean. For those who want further improvement a trip to the nearest "chippy" for a bit of re-programming will deliver additional benefit.
Like most things motorcycle related "you pays your money and takes your choice"
imho , it goes something like this :
(a) if its just a slip on , there is no "real" gain (may actually end up with a mid range loss). No need remap , etc.
(b) if its a full system (manifold , mid , end can) and if they say no need to remap and its just "plug and play" , don't bother because it just means that it doesn't do what a full system is supposed to do.
(c) a proper full system will require a remap because of the exhaust gases are flowing much free'er. If you do not remap , you may end up too lean. Remap will yield "substantial" power gains here.
I hope I got it roughly correct
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(a) if its just a slip on , there is no "real" gain (may actually end up with a mid range loss). No need remap , etc.
(b) if its a full system (manifold , mid , end can) and if they say no need to remap and its just "plug and play" , don't bother because it just means that it doesn't do what a full system is supposed to do.
(c) a proper full system will require a remap because of the exhaust gases are flowing much free'er. If you do not remap , you may end up too lean. Remap will yield "substantial" power gains here.
I hope I got it roughly correct
.
Based on personal experience I would say no and offer an alternative summary:
a) just an Akro can fitted gives some noticeable improvement. You also get more noise and less weight, if that's your thing then bingo!
b) Akro can and Remus headers (minus cat and flap but with Lambda sensors) gives a very noticeable improvement with no problems at all and it doesn't run lean. This is backed up by other LC owners who have done similar, plus the published test data from manufacturer. IMHO a perfectly good upgrade.
c) all the above plus re-mapping would give biggest improvements (as would re-map for any exhaust system).
The big question for me is what happens with a re-map on an LC given that it has 5 different programme modes whic affect a number of parameters including engine characteristics. Does that mean it has 5 different engine maps, or one base map which is modified according to chosen programme?
Has anyone out there re-mapped an LC?
Don't worry about answering that one, just found the appropriate thread! Just need to find half a day to go through it all ;-)!
GC6269
Registered user
When you've done that, would you mind popping back here and giving us an abridged version of it??!!
Ok here goes:
Those who have chosen to do it have spent quite a bit of effort explaining why it was the right choice for them and has made them happy.
Those who have chosen not to do it have spent quite a bit of effort explaining why it is the wrong choice and why it wouldn't make them happy.
Those who couldn't care less either way don't seem to have posted anything!
The principles above would also seem to apply to this thread too, and maybe even life in general
Hope this helps?
I've now fitted my akra headers and i thought I'd run it up to make sure it was not blowing, i stuck my standard can back on (instead of my akra) and fired it up, oh boy its got an angry bark, infact it sounds pukka with the stock can and seemed to rev a lot faster.
I'm going to be having some Dyno time, before and after so ill let the Dyno tell me if it running lean and if it warrants having a re-map.
If i had the option again I'd not buy the akra can, just the akra headers with stock can, sounded Absolutely Fantastic..
I'm going to be having some Dyno time, before and after so ill let the Dyno tell me if it running lean and if it warrants having a re-map.
If i had the option again I'd not buy the akra can, just the akra headers with stock can, sounded Absolutely Fantastic..
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