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Build Thread: Akrapovic Undertail...& some. (PIC HEAVY)

17K views 87 replies 36 participants last post by  Pharaoh6 
#1 · (Edited)
I've had a good number of inquires on my undertail exhaust project and I'm finally getting around to putting this thread together. Turns out I have enough pics to make it exciting :D:D

Quick background. 2009 R6. This bike started as my garage obsession just to mod/personalize, like 99% of you. I ended up doing an amateur build for some shows...for fun...but this is a bike I track 80% of the time and commute to work on/ride the hills 20% of the time when I can.

My mods are listed in my sig, but I'll focus on the exhaust. Lots of pics and detail to post so I'll do this one day at a time...because I do have a life and work to tend to :comp

So how did I get from pic 1 to 2 then 3. I'll talk about pic 3 since you're all versed with the first two and how to pimp your 6 out for track or street or both.

Good thread...imminent :too cool:

UPDATE!! (11/18/14) ....there is now a pic "4 & 5" which I'll update with a final pic once complete. I continued this build with the dual R1 setup. Read on :toocool:
 

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#5 · (Edited)
Thank you. Chose the titanium for less weight...and I got this can on clearance. Full price on the titanium Akra is no bueno :) I wasn't trying to spend the cost of a new bike with this build, but rather keep it somewhat reasonable still yielding a good end result.

Horsepower definitely wasn't my main goal, but overall power was a goal in mind. I ended up dyno tuning this final setup one cylinder at a time. I had bungs welded on my headers.

My first instinct with this project was "don't do this, you're going to raise the center of gravity weight wise." To be honest though, the weight difference was negligible. I couldn't believe how light the Titanium arka can was. With all the weight savings from the rest of the mods, I don't really care. This isn't a prototype race bike and she's plenty capable on the track. The dyno tune along with the ECU flash were important to me to make sure the power band was smooth along with the air/fuel.

I did a dyno tune in July and made 109 at the rear. The recent one tuning each cylinder yielded 115 at the rear wheel. So considering stock is what, about 100 at the rear? I'm pretty happy with a 15% increase with the current engine mods. With the flash, tune, motion pro throttle kit.....she feels way different than last summer. I'm very happy with the end result power and feeling wise. Overall performance, but something unique and clean was the goal.

Also, although I'm sure a few are out there, I don't think I've ever seen a cleanly done undertail conversion on a 6. That was a big motivation as well to make this a reality.

More pics/detail to be posted tonight...

those are 190's in the rear right? What pressure are you running? I'm running 21 rear 33 front. I'm on the 190 rear and 120 front GPA's
Nope 180. I didn't favor the feeling of a 190 on the track. For street, it doesn't really matter though.
 
#18 ·
Yea, I keep telling myself that :D If I decide to put that much more money in this bike, suspension and wheels are for sure next.

Super creative and looks great. Did you do the welding and exhaust work yourself or?
The actual welding, no. Just the design. My original intention was to do titanium pipe all the way up and my guy can weld titanium so he was the man for that....BUT...titanium hard to find and near impossible to buy in small portions which makes it super expensive s you can imagine. Ended up doing a thin gauge 1 3/4 stainless. Still lightweight.

I tried calling you today. Ill try again tomorrow need a few pieces of info from ya Ramsey.

Callin ya...
 
#12 ·
That is so clean!! Very impressive!!!
 
#13 ·
:hump that is one sexy bike. In to see how you made it all happen.
 
#20 · (Edited)
Ok, here's where it all started. Came across this sweet slip-on and was able to take it home to mess around with it a bit before committing to the purchase.

I asked the wife to hold it up, probably a few too many times, so I could sit there and contemplate if I was crazy thinking this could be a possibility.

Probably just crazy thinking I should ask her to hold it there while I contemplate spending money :sing

Wife: "but don't you already have a nice exhaust?"
Me: "yes hun, but that's not the point. I could build something really cool and one off with this"
Wife: "but don't you already have a nice exhaust?"

haha...repeat this convo...with most mods :D (I'm being a jerk, she really is awesome and supportive...mostly) :D

Looks like it could be a possibility without too much work right? Yea...about that.
 

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#21 · (Edited)
So here's a good shot of one big issue with this mod. Tire clearance.

There obviously isn't much because the R6 wasn't designed for any size pipe under the tail. This became the main struggle, because when I pressed the can up against the bodywork of the tail there was only about 3 inches between the can and the tire. A 180 tire mind you. Obviously not a safe amount of clearance.
 

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#22 ·
I had the same issue in the beginning and I'm running a 190 GPA which we all know has the same measurement as the pirelli 200 corsa's lol hense why I changed it to duels :D
So when you gonna sell the setup haha
Any chance you got a weight measurement on entire system?
 
#24 ·
Quick shot of my moto cave....then finally took the tail apart to see what I could do...
 

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#26 ·
Maybe I should have mounted it on like this? :) ...less work for sure.
 

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#27 · (Edited)
The top center part of the subframe where the stock plate mounts needed to be shaved down. Only way to gain some clearance considering there would also be some bodywork under that. I left the throttle side passenger peg attached so pipes could be designed around that in the event I take them on or off. The new slip-on basically needed to be set up higher in the subframe.

I love the side view of the R6 without any tail bodywork. If I did this again, I'd build it with very limited tail bodywork to keep this short tail look. Love that.
 

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#28 · (Edited)
At the shop now and the shaving begins. East Bay Fabrication in Dublin California. Kyle (owner) is the man...an artist in his weld work to be honest.

Figured removing the stock plate mount would be enough. I figured wrong and had to keep shaving.

Then put the slip-on mounting bracket in, which luckily was almost the exact dimensions to where it needed to mount. We had to make 1/2 inch spacers to get the mounting hardware to line up.

Grind down....hold up the can for clearance....more grinding...
 

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#29 ·
In the end, the whole center piece had to come out. After several long talks about the integrity of that cross piece in relation to the subframe, we concluded it was fine and cut it all out. As long as I don't two up with a elephant, there's no problem :D


...and one cool shop pic.
 

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#30 ·
She's finally mounted in place.

The next fun part begins. How to get from Point A (header x-pipe) to Point B (slip-on) while keeping very tight clearances between the swingarm/rearsets/tail bodywork....and my right leg eventually....because it's going to be HOT :fact

No problem right....and so we discussed and starred at the bike....foreverrrrr...until the best plan for the connecting pipes fell into place.

stay tuned...
 

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#32 ·
Aaaaaand theeeeeen...

:popcorn:
 
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