It doesn’t smell. If it’s fuelling correctly why would it?
Dance with the Diavel.
- Thread starter Arsey
- Start date
Larry Langford
Registered user
Well, a non catalytic exhaust has a powerful, distinctive smell and is quite poisonous.
Sorry for the bother, over all, but it seems that aftermarket exhaust that came with the bike does have cat, just by guessing, from the looks of it. But that would be the first time I've seen that. Specifically a full replacement performance exhaust with a cat in it. Which is a good trend imo ......
I watched a tube channel called 650ib back in the day. He generally had about a dozen sport bikes at anyone time. Well, he bought a M1000RR and and had his local dyno shop put on a full TI racing exhaust on it. And unlike most folks he did a before and during and after dyno, on the bike. I think he spent about ten grand or something like that. Shorter story, when they put the bike on the dyno after installing the new exhaust they couldn't get the bike back to the stock horsepower. This turned into a struggle, and the they pulled all the videos on it. They did end up claiming a very small HP increase but I have my doubts. Being an ex-racer myself.
I have a theory that modern cats are so high flow that they don't really cause that much of a problem and may somehow actually improve flow like say an afterburner effect somehow. Take Remus for example, and the R1250RS. Remus published a graph on there website showing the power curves with the stock exhaust, the stock exhaust with a Remus can, and the full racing exhaust. They seem to have pulled this graph off the website, but the stock with remus can was neck and neck with the full exhaust all the way to 8000 rpm and then the stock with can started to level there, the full exhaust climbed a little. The differenced turned out to be 4 HP, and only above 8000 RPM. Hence the graph has been pulled off the website, last time I checked. I shift mine at 8000, if I'm blowing the cobbs out of it. wink
Why anyone would go with the full exhaust is completely unknown to me ...... go at least as fast and keep the air breathable and possibly even be legal ....
I do have the graph saved here somewhere if one wants to see it, I'll try to post it ...
The bike came with the full Akra.
It saves 11kgs and adds 13bhp.
It certainly has great fuelling .
I wouldn’t have paid £5k for an exhaust system though.
Sorted
Larry Langford
Registered user
Yes this answer seems the most likely .... I looked up several adds for this exhaust, and none of them clarified this question but one add, did say that this exhaust is for closed racecourses and then directly stated the 108 decibels @ 5000 RPM with baffles. 109 without ...
My question is why keep the collector? I did see at least one other exhaust for this bike briefly, and it was all pipe. Usually you get rid of the collector if you get rid of the cat/cats .... It would be interesting to see what akro had in mind, especially considering this is not a race bike, why SO loud? ...
Also, in my opinion, The measly 7 HP increase with 6% increase in torque, and 5750 US dollars cost doesn't seem like this will roll imo. 7HP out of something like 170 HP is probably barely even out of the range of calibration for a dyno it seems ... But pro verses con, it does save about 22lbs ...
I use Kriega packs as well a 40 litre with a 5 litre on top, great for quick finds of smaller items, fully waterproof, great quality.
Don't forget to take the shoulder strap makes it much easier to manoeuvre when off the bike. I use my old camera shoulder strap just to pose with.
Don't forget to take the shoulder strap makes it much easier to manoeuvre when off the bike. I use my old camera shoulder strap just to pose with.
Do people buy full systems for more bhp ! I would imagine many buy for the sound and to allow it to breath better, .
Akrapovic spend a lot of time with R&D, they don’t just slap a system together for retail, If you understand flow and pressure then you will realise they have most likely designed the collector to manage the complexe of the header pipes, also it will optimise the flow creating a vacuum that alone will help to pull the exhaust gases out the cylinders this will give it the hp increase, the collector will space all the pipes evenly again to reduced back pressure, giving a smother flow.
Larry Langford
Registered user
Well, I'm an older tosser lol and we used to get numbers like 15% or even 25% increases in power, when we ditched the muffler and went to a KN air filter. And re-jetted the carbs too. The whole idea of better flow is simply more ponies imo ...
Or, they simply kept the cat and just didn't tell anyone. If this is the case, then they avoid the tuning problems you tend to inherit, after ditching the cats. I did mention that already in the above posts, about the case with the M1000RR. Personally, I think that if you wanted to ditch the cats, on a sport oriented bike if think a different stripped down computer, like say one they use in motoGP, with out all the parameters for noise abatement and emissions would make that work much better imo .....
I think that this hasn't been settled and there may still be a cat in that huge collector. After all what would it hurt? the newer cats do have very good flow compared to the ones from the 70s for instance ...
The Akra is a tad too loud to be honest .
But it sounds like a race bike and had perfect fuelling .
Still running it in up to 6000 ish and redline is 11500. God knows what it will go like when I get it off island next month and can give it the beans after it’s first service .
The Akra race system do not come with any cat whatsoever.
It will not smell because the fuelling will be 100% correct, that particular system as per all Ducati race systems come with an up map that is dealer up loaded.
Larry Langford
Registered user
Well I looked up several adds, and that was more common than the `13 HP increase. But these are estimates and in reality it might not be too much of an increase, when on a different dyno ..... and of course the tuning is critical .... And who could tell the difference on 170 HP bike .... not me
You are still the one who has actually rode this bike and of course should be able to tell if there is in fact a cat in that collector ... imo ... But would you be honest?
Larry Langford
Registered user
wrong ..... untreated exhaust has a noticeable odor .... And like I said earlier the tuning isn't easily settled when altering the exhaust ....
They designed the exhaust collector to prevent over smell by creating the vacuum, the map tuning that the dealer loads when fitting this system has the ability to lean-map configuration, as i said Akrapovic spent a lot of time with R&D and getting the up map tune perfect.
I am intrigued, instructions for the Diavel akra kit say different chain & sprocket needed. Doubt it is a clearance issue cos chain is on the opposite side to the exhaust system.
Larry Langford
Registered user
The whole idea of a perfectly tuned performance engine having no detectable odor, without a cat converter, is ... absolutely absurd ... You really don't know the difference between one or the other?
Actually in racing, unless if fuel consumption is a issue, they tend to set them up a little on the rich side. So there is no way you can achieve low emissions without a cat ...
I think you may be confusing me with someone who gives a shit
Couldn’t give a flying fuck whether it makes 140 or 180 bhp . It’s stunning to ride . But you seem obsessed with cats and odours . Weird.
It's only a 170 bhp motorcycle if you twist the throttle enough, which let's be honest, hardly any owner is going to do. This bike will be too quick just riding the initial torque curve
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