Hi all, some might have seen me posting on the forums already but I haven't really posted any pictures of my bike yet. With this mod taken place it is a good time to introduce my terra to the whole forum now. Today I had a appointment with the best exhaust specialist in the country to discuss aftermarket exhaust options for the Terra. The only 'mass produced' exhaust I have found for the Terra are the GPR ones but I don't like the look of them and I am unsure about the quality. I rather stay with some brand that I already know and have used before, thus my preference went out to a hexagonal Akrapovic can. My exhaust specialist said that anything is possible and he forged custom headers within 2 hours that would make a 40mm Hexagonal Akrapovic can fit the Terra. Here is my Terra on the lift: With the OEM cans removed: This is the 40mm Akrapovic can that I choose, my exhaust specialist has over 200 brand new ones in stock but I chose this one because it approximately has the same length of the OEM cans and according to the specialist shorter cans wont survive a single cylinder and it will be obnoxious loud. The can I choose is initially a right hand side exhaust but it is made to fit on the left side with a customized carbon hanger. I have weighted the OEM cans and they weight 3.5 kg each while the Akra only weights 1.65 kg. The tail is pretty neat without the cans, it kinda looks like a sports bike tail. The exhaust specialist welding the header parts together. Eventually he used 3 different sized and angled customized stainless tubes to make the Akrapovic fit. Almost there, only one stainless tube to go to connect everything together, the can is installed to get a sense of how the exhaust can be placed best (angle, protrusion). Welding the last parts together. And it is installed! Just add a OEM Akrapovic sticker on the left side and behold the final result! Because the hole of the hexagonal can is so big I had to relocate the turn signals with brackets so that they wont get blown off by the exhaust. The exhaust sounds AMAZING! WAY to loud though without the baffle installed and still extremely loud with the sports baffle installed. When you are near the bike running stationary you can feel the shock of it just like the bass at an concert. I also installed a Power Commander V with Autotune and the bike runs great, no stalling or any other problems anymore! Also I barely have any engine braking after these mods, I am not sure if I like that side effect. I also got the swing arm drilled due to the fact that I have been riding in some rain lately but my swing arm is still bone dry after 3000km on the clock. Do you guys fill up the holes you drilled at the bottom?
No engine braking? That's odd. Is the power commander opening up the bypass valve or something? That's about the only thing that could eliminate engine braking,
Hmm I have a problem with the Autotune unit, it does not give me any trim tables while I have driven over 300kms with it. I do get a variable AFR value on the right side of the PC V software but I can't seem to get the trim tables. It also shows 2 devices connected so I am wondering what the problem is. Can it be the positive wire of the Autotune that is connected wrongly? I Positapped it to the green/white wire under the main fuse box. The green light of the Autotune being active is not active either.
That'd make sense then. Engine braking comes directly from engine vacuum which would be decreased if the bypass valve was opening.
I don't believe it is from any bypass valve opening, simply from richer fueling. My experience is from using a special made stock/-40deg Wuka King air temp spoofer. When set to Stock (no spoofing, stock lean fueling) mine has lots of engine braking. With the Spoofer set to a -40 deg offset (which makes it run richer) it has very little engine braking. You can flip between the Stock & -40 deg settings and notice the significant difference in engine braking.
My guess is that the oxygen sensor is telling the ECU to open the bypass valve to let more are into the mixture to compensate for the unburned hydrocarbons being sniffed in the exhaust. The O2 sensor detects unburned hydrocarbons by the amount of oxygen in the exhaust stream. Rich means no O2 in the exhaust stream so the emissions algorithm is going to open the bypass valve until the O2 sensor detects oxygen. Engine braking is a function of engine vacuum which is directly proportional to throttle opening, rpm, and to a lesser degree, ambient pressure. I'm not sure how a richer mixture would factor in to that but there may well be some factor of which I'm unaware, like vaporizing fuel or something like that.
I finally figured out why my autotune wasn't trimming, the stock map does not contain a AFR table so I had to input some figures manually. After today's ride of 150kms I accepted the trim table and the engine braking is pretty much back again although not in the same magnitude as the OEM setup. Losing engine braking was probably due to the fact that the PCV contained an extremely wrong map for my current setup. My Oxygen sensor is connected to the Autotune and not to the ECU so would that O2 sensor even be able to tell the ECU to open the bypass valve?
Very nice! Definitely the right way to install a custom exhaust. If it wasn't for a few things I really like about the stock exhaust I would have made the same modification to my Terra already. Can you please post additional pictures of the final installation? Of the entire system? Thanks.
Cam you please provide additional information on the exact model #, etc. for the Akrapovic can? Thanks.
Sorry for ignoring you for so long, I just got a notification that you replied. Here is a recent picture where you can see the exhaust and its headers sort of... It takes the stock route to the engine so it is kinda hidden behind that black plastic part and frame. I wouldn't know the exact model # because I just took one out of the warehouse of my exhaust specialist they are generic 40mm Hexagonal exhausts that are used for pretty much any sportsbike that has a side exhaust. The system still runs great in combination with the PCV and Autotune, I took out the baffle because it feels like the bike runs better that way.
Hello Everyone, I hope this is allowed "cross threading"? If not the admin is free to remove this post. Seeking a lighter and less costly exhaust (GPR) I came across a fellow Terra rider here in the Philippines - Arvin that had installed a LEXX Mxe Can and had a brand new spare Lexx. I was already running my Terrable with the Pod mod, AF-Xied (set to 8) with my original cans minus the Baffles & Packing and was happy with the performance. A month ago I installed new gearing 15/49 as recommended by High Five - and really like that set up. So on Feb 1st I went to Arvin's and he did a great job (see link) the whole system FEEL's smoother, grabs the rev's a little sooner and handlebar vibration at 75 mph is reduced 15-20% ? (I removed the bar weights about a year ago) I kept the quiet insert in and REALLY Like the Mellow Sound. + also had to relocate the directional as the right one started it melt. This looks to be a viable alternative for us TR Guys. Regards to All Here, Chris / http://www.cafehusky.com/threads/out-and-about-terra-strada.28425/page-38#post-564879
