Alright guys. Prepare for what I'm guessing will seem a real jackass question: I have slip-on carbon Termiognis waiting for me at the dealer to install on my M821. I know I love the look and I understand it improves the sound. But I want to believe that there's also some practical benefit in terms of performance and such. Am I destined to be disappointed, and did I just spend about $1,500 on a mere cosmetic tweak? Damn I feel stupid just asking this question.

You might get a couple horsepower...bit it's mainly about the looks and sound. The sound should be worth it though! 

What TripleJ said.

On modern bikes, you aren't likely to see much improvement with only one mod.  And mods to make "real" power will be punished in the "streetability" department.

The sound is DEFINITELY worth it!  I waited a couple years to buy pipes for my first Monster.  The second Monster...pipes were one of the first mods.  $1500 is a pretty penny to pay though.   Just as good of sound with cheaper alternative steel pipes.  But..you will most likely be satisfied the first time you open it up and engine break. The price will be an after thought by then.   

You might be dumping a considerable amount of weight as well. I don't know how the 821 exhaust is configured, but most slip ons save decent weight. 

Maybe only a couple or a few peak hp, but improved response and filling any EPA midrange holes in the torque curve are common benefits. Tune the ECU and you will probably get more.
So don't despair, it was worth it.

Ok, question, are you getting the HOMOLOGATED Termis or the "RACING KIT" Termis?

With the first one, you still get a CAT, loose weight and have CF and the ability to decide if you want the baffles or not . . .

With the second option you get: straight through piping, NO CAT, less weight and an UPMAP or 'REFLASH' good for up (depending where you are) net gain of 8%-10% power and torque(as explained to me by factory Service Manager) . . .

So, you do gain power and torque, and yes, you will feel the difference, specially in SPORT mode

I hope this answers your question . . .

Quote from: koko64 on February 28, 2015, 10:43:17 PM
Tune the ECU and you will probably get more.

Is that something to be done by the service center?  I seem to recall hearing something about that when I bought the bike.

Quote from: The Last In Line on March 01, 2015, 06:15:54 AM
Ok, question, are you getting the HOMOLOGATED Termis or the "RACING KIT" Termis?

I know mine lacks a catalytic converter (CAT?). Does that narrow the options well enough? By the way, what is "homologated?" Either way, I can't wait to slip those pipes on and try em out. Loving my new 821. As a newcomer to riding, I really appreciate all the help.

Quote from: texasmonster on March 01, 2015, 07:27:38 AM
I know mine lacks a catalytic converter (CAT?). Does that narrow the options well enough? By the way, what is "homologated?" Either way, I can't wait to slip those pipes on and try em out. Loving my new 821. As a newcomer to riding, I really appreciate all the help.

http://bit.ly/1DpVprv

You could buy the expensive DP ECU or get the ECU reflashed or even the trim adjusted. I dont know if Power Commander or Rexxer have options yet. Someone will chime in who knows. Your options depend on the capability of the dealer or local tuners and tuning parameters of the current ECU.  Termi kits can often come with a DP ECU too.
Last in Line will know the options (hes a dealer tech).

Pretty sure the race kit comes with a different ecu/map.

I'm reading all your minds: " This dipshit dropped $1500, and doesn't even know wtf he's getting?!?" Yes, this dipshit did that, exactly. This dipshit was in an "f-it" mood that day. And this dipshit thought Termis look like the tits. 

ha ha...no worries. I always get exhaust as well, mainly for looks and sound. Lower weight is nice, as is any HP increase. But honestly, the bikes are just fine right out of the box for street use if you're talking practicality.

So...it's all about looks and sound in the end. 

At that price I'm pretty sure you have the DP computer.  Closed loop operation will be about the same performance wise.  Open loop is where you will feel the improvement.  Congrats on your purchase and welcome to the board.