Jump to content
Guest brickst3r

Termignoni or Akrapovic

Recommended Posts

Guest brickst3r
Anyone here have the Termignoni exhaust yet? I'm either considering that or the Akrapovic carbon/titanium. I think it'll be down to those 3 but just not sure what i want yet. 

Share this post


Link to post
Share on other sites
jbird
Akra carbon it looks nasty on this bike, it's so fucking sweet
  • Like 1

Share this post


Link to post
Share on other sites
Guest brickst3r
do you know why they added the extra loop on the akra carbon right before the muffler? the termignoni is a straight pipe all the way to the muffler. I don't know much about exhaust pipes and stuff so not sure why they added the loop.

Share this post


Link to post
Share on other sites
snowdriftless
This has already been discussed:
 
Akrapovic Carbon exhaust
 

Dewski, To answer the question, why the loop?
 
I was told the AK Carbon was engineered that way to increase back pressure to compensate for the short length of pipe and muffler.
 
 

Share this post


Link to post
Share on other sites
jbird
Send link for the thread on the loop engineering

Share this post


Link to post
Share on other sites
partysub
I have the termignoni sitting in my garage waiting to be installed. I'll post a review once I get it installed hopefully this weekend.

Share this post


Link to post
Share on other sites
USMCFieldMP
For those leary of the "loop" that the Akrapovic Carbon has, realize that some MotoGP bikes run/have run their exhausts/parts of their exhausts like that.
 
 
 
Honda-RC213V-MotoGP-Laguna-Seca-Jensen-Beeler-17.jpg
 
1384270479-907142219K-o.jpg
  • Like 1

Share this post


Link to post
Share on other sites
Guest brickst3r
Those welds on the loop look amazing with the bluish color.

Share this post


Link to post
Share on other sites
aeisan
I don't know why it gets under my skin when people refer to a motorcycle exhaust needing "back pressure" but it does... It's just a fallacy; or at best a misnomer. Back pressure, literally the actual back pressure, is not desirable characteristic of any ideal exhaust.
 
The whole point of an exhaust system is to exhaust the resultant gases from the combustion cycles out of the motor. To do this, there is a specific velocity that is ideal for each system. You don't want too much or too little else you loose torque and power. Thus, the loop is there to achieve the desired exhaust velocity - not back pressure.
 
Every bend, weld, inch of pipe, pipe diameter, pipe wall thickness (because it effects the way the pipes expand/contract when heated/cooled)baffle, etc. play into how the exhaust velocity is achieved and it's all there because the engineers want it there. Just because some systems have the loop and some don't does not mean one is right and one is wrong - they were just engineered differently and you have to take the entire system into account, not just one bend or loop.

Share this post


Link to post
Share on other sites
pattonme
well, if we want to split hairs "back pressure" IS desirable (to a point) since it's the reflected wave form that helps scavenge the cylinder. As soon as the diameter of a pipe changes you get a reflected wave. When the gas hits the canister entrance (and exit) reflected waves are sent back to the exhaust port. These wave fronts going the "wrong" way are indeed back pressure as they run into the next puff of exhaust trying to get out.
 
The length of the pipes is used to tune the timing of these waves. Acro knows their stuff and a twin REALLY benefits from longer headers but given the limited packaging options they did the best they could by putting in the loops to get another 10 inches or so. The "barrel" shape is also deliberately engineered to help with gas flow dynamics.
 
  • Like 1

Share this post


Link to post
Share on other sites
aeisan
Thanks for the correction! Great point... I guess you're right in that it would help the scavenging, but it's not the only factor if I understand things correctly. That said - I'm no expert in gas dynamics ha, just a structural guy that took enough fluid and thermal dynamics to be dangerous.
 
You did, however, help reiterate my main point I wanted to make to others - which is don't judge a book by its cover. I get the feeling not a lot of people realize how truly complicated the engineering is that goes into these (and any) bikes and that everything is there for a reason.

Share this post


Link to post
Share on other sites
pattonme
> how truly complicated the engineering is that goes into these
 
Just wish yamaha would spend the time on the dyno putting a fuel map together that wasn't total shite.

Share this post


Link to post
Share on other sites
bigity
In response to the OP, after 7 months of Yoshi on my Fizzy, I just bought a Termignoni.....

Share this post


Link to post
Share on other sites
blueangel
I just ordered the Termignoni from Carpimoto. Really looking forward to receiving it.

Share this post


Link to post
Share on other sites
vertigo
Cue countdown until someone has a story of a bystander asking why they have "exhaust from one of those dew catties on yer Jap bike..."

Share this post


Link to post
Share on other sites
gregjet
I am beginning to really like this forum. Actual informed arguements and points.
Sorry but I have to add this to this thread and YES I have posted it before. As several pointed out above, it is the pressure waves and their behaviour that is the reason to change to an exhaust that allows these to do their job. I won't go into a long explanation but this bike is at a serious disadvantage when attempting to use additive scavenging ( each cyl pulse helping the other/s extract and reflow). The problem with this Yamaha's exhaust is that the firing order is 90/270 degrees which puts the pulses at almost exactly the wrong phase to help and infact will REDUCE the beneficial effects. Any 2 into one exhaust on this bike will not produce theoritical max available HP at design point revs.
HOWEVER, the std exhaust SYSTEM sucks ( sorry about that) . Actual substantial backpressure , no design harmonics and VERY heavy ( ridiculously. Akrapovic is on record as saying that perfectly good catalysing can be produced with a tiny fraction of the size and weight used by almost EVERY manufacturer of bikes). A good replacement system will reduce weight of the bike ( a good thing) . For any well designed cat included pipe ( eg GPR cyl cats) is as clean as the factory pipe and will be CLEANABLE. Produce a bit more power. Look way better ( not really all that important but it's there. Sound better ( again not all that important but it's there and THIS bike really does sound good even when it isn't too loud). And be easier to work on the bike as they are usually easier to remove and replace. In my opinion THAT is why you change the pipe on this bike.
  • Like 2

Share this post


Link to post
Share on other sites
Beemer
All I know is the loop or the "combustion route reburnifier doo-hickey" which the Akrapovic carbon has, creates more torque in the low and mid range rpm's and you can actually hear the pressure waves resonating from the pipe and the straight Yosh pipe creates more h.p. up top and less torque down low. The Akrapovic carbon gave my bike balls and it sounds bad-ass so I recommend that pipe! Yesterday, some guy was walking with his girl and heard me coming from behind, he about snapped his neck to look around quickly to see what sounded so bad-ass and motioned for me to do a wheelie. I declined because I couldn't do a wheelie and check out his girl at the same time and the look on his face let me know I have a bad-ass bike.

Share this post


Link to post
Share on other sites
ryan4130
@gregjet in your opinion, what are the top 3 or 5 exhausts for our bike currently out? (Preferably sorted in order). You seem very knowledgeable on the subject and a list would be great if you would write one :)

Share this post


Link to post
Share on other sites
vertigo
I am beginning to really like this forum. Actual informed arguements and points. Sorry but I have to add this to this thread and YES I have posted it before. As several pointed out above, it is the pressure waves and their behaviour that is the reason to change to an exhaust that allows these to do their job. I won't go into a long explanation but this bike is at a serious disadvantage when attempting to use additive scavenging ( each cyl pulse helping the other/s extract and reflow). The problem with this Yamaha's exhaust is that the firing order is 90/270 degrees which puts the pulses at almost exactly the wrong phase to help and infact will REDUCE the beneficial effects. Any 2 into one exhaust on this bike will not produce theoritical max available HP at design point revs.
HOWEVER, the std exhaust SYSTEM sucks ( sorry about that) . Actual substantial backpressure , no design harmonics and VERY heavy ( ridiculously. Akrapovic is on record as saying that perfectly good catalysing can be produced with a tiny fraction of the size and weight used by almost EVERY manufacturer of bikes). A good replacement system will reduce weight of the bike ( a good thing) . For any well designed cat included pipe ( eg GPR cyl cats) is as clean as the factory pipe and will be CLEANABLE. Produce a bit more power. Look way better ( not really all that important but it's there. Sound better ( again not all that important but it's there and THIS bike really does sound good even when it isn't too loud). And be easier to work on the bike as they are usually easier to remove and replace. In my opinion THAT is why you change the pipe on this bike.
 

I like how it makes my bike go VROOM VROOM. :D

Share this post


Link to post
Share on other sites
gregjet
RYAN, PLEASE NOTE I AM NOT AN EXPERT ANYTHING. SO ANYTHING I EXPRESS WILL BE AN OPINION. An opinion based on what I know , but an opinion nonetheless.
First IMHO none of the current exhausts are right . For reasons I have ranted on in this forum repeatedly. However, even I have changed the exhaust . Primarily for WEIGHT advantage ( plus I like snail pipes. call me shallow)
I like the GPR GPE, the Akro Carbon and the Yoshy ( yoshie's are usually heavier than they need to be, but can usually be relied on to give good power IF you retune the fuel). Elsewhere in this forum is info saying that both the Akro and the Yoshy produce MORE power with the baffles IN. So you may want to take that into consideration. No one here seems to have bought any of the GPR's which seems strange as they are VERY good exhausts , with a nonrestrictive inline cat and usually cheaper than the others. Their work can be a bit inconsistent , but that is because everything is handmade and they upgrade as they see changes needed. No production lag. If Tyga ever makes a set for this bike consider them. Seriously. It will be cheaper and VERY good.
If anyone manufactures a long set of 2 into 2 buy that.
 
  • Like 1

Share this post


Link to post
Share on other sites
pattonme
I'm not having much luck finding good details on GPR/GPE for the MT07. If this is any indication of the extend of current offerings the headers are long but it doesn't look like they addressed the pulse timing issue.
http://www.ebay.com/itm/Yamaha-MT-07-FZ7-GPR-Exhaust-Full-System-With-GPE-CF-Carbon-Look-Silencer-/271687410163
 
Hmm, then again maybe they have: http://i.ebayimg.com/00/s/OTYwWDEyODA=/z/n6oAAOSwO7pVAp81/$_57.JPG
 
This looks interesting: https://crysellcycleexhausts.com/Mt-07-Gpr.html
 

Share this post


Link to post
Share on other sites
ryan4130
@gregjet thanks for the reply. I definitely understand your option is not law but have seen your other posts where you discuss exhaust design and I am intrigued. I currently have a yosh system, baffle in. Have not even tried baffle out...it's loud enough as is

Share this post


Link to post
Share on other sites
norcal616
Leovince makes prolly the shortest exhaust out for the fz-07...the headers are tapered for the first 6-7 inches....then it tapers again at the last 6-7 inches before it goes into the "cat" inside the mufffler...Leo Vince did this design to place the heavy muffler/cat combo directly under the bike which I like from a balance perspective... OminiaRacing is sending me the " cat" free of charge since it was somewhat was omitted from my kit...I have a good feeling that runing the exhaust with no baffle and " cat" installed will create the engine behavior I'm looking for compared to currently using no baffle or "cat"...

Share this post


Link to post
Share on other sites
gregjet
Norcal, The LeoVince approach is a bit strange. If you narrow the exhaust properly you can shorten the harmonic length but not much. The muffler on most of the aftermarket systems is so light it will have very little effect on centre of mass. Std exhaust ,..yes, most aftermarket ones ( maybe Yoshy excepted, and all the Delkevics I have seen) ...no.
The LeoVince approach also would give better torque at a lower rev point ( theoretically) which this bike would like .
Pattonme, that third link is a bit sus. Takes me to a wierd picture page, different each time.
Out of phase problem will still be there in the GPR GPE. I would have bought that system instead if it had been available when I bought my Akro Carbon. I like GPR stuff. Another MotoGP supplier for those who don't know. And that system comes with a nonrestrictive ( relatively. 100csq") inline cat. BTW the inline cat will help modulate the out of phase problem as it tends to soften the return pulse transient.

Share this post


Link to post
Share on other sites
stix
I'm having a serious battle of the conscious on whether or not I want the Akra Carbon of the Termignoni carbon...so I figured I'd try to bring this thread back to life considering its been dead for a month. Any updates/changes of opinion on your exhaust choices? How are people liking the Termi and has anyone had the opportunity to hear both the Akra/Termi in person?

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



×

Important Information

By using this site, you agree to our Terms of Use.