I have no aftermarket slip on system, it’s perfectly standard apart from me opening the exhaust up, removing the cat inside and welding it back up again, there is a thread on it plus pictures. https://www.ducatiforum.co.uk/threads/exhaust-winter-project.66061/ Ok I did leave the flap open and using the Duc-EE thing, but I stand by what I say, it’s smoother on the throttle when accelerating. I did on a previous bike have an aftermarket can and had it remapped on a Dyno, with similar improvements.
Hi BigAlan, The surgery you preformed (which is cool btw) is akin to reducing the exhaust resistance and improving flow. It may not be apparent subjectively, but you have leaned-out the engine nevertheless.
Some do give values and dyno graphs https://d1sfhav1wboke3.cloudfront.n...0500/d94a4e1d-5471-4a78-abce-d1bdaff397c4.pdf https://www.akrapovic.com/en/moto/p...r-Titanium?brandId=46&modelId=400&yearId=4477
@bradders That's not for a slip-on, it's for a full system. The improvement although minimal are mostly at the top end. Even then, it messed-up the torque curve where you want it flat. Again, that's a full Titanium system including headers and without baffle. Big bucks for very little gains. I'm really sorry that we've deviated for the OP's topic which was essentially, best value mods. Leaning out the engine by disabling the exhaust valve may be a sound improvement but does nothing for improving performance and I have yet to see a chart that proves it without an accompanied fueling mod.
Having written the above, and with a bit of patience from you guys (since I'm snowed-in) I will do just that. I have a 1260 Multi PP all paid-up waiting for me to take possession in the spring. I also have a Rapidbike unit which I can have re-programed with a new base map. After break-in, I'll have it dyno'd stock for the first few passes. I'll then disable the exhaust valve and run a few more passes to compare. Finally, I'll install the re-programed Rapidbike with the exhaust valve disabled, let the RB unit learn and auto adjust, then return to the dyno a few weeks later for a few passes. I'll try to choose a similar temp and humidity day to eliminate that variable as much as possible.
True that. My objective will be to "both" increase and improve the flatness of that rpm midrange section where the valve initially closes then opens a few rpm's thereafter.
Slip-on without any cat change will make no performance difference at all. Start a bike up with no end can on and it is no louder, the silencer is pretty much superfluous, the cat is doing most of the work. I agree with Alan, fitting a cat-bypass (or de-catting in his case) does make a difference. I agree with you Dar that it reduces back pressure, which allows the bike to actually run both smoother and seems (subjective) to accelerate cleaner. I disagree with you that the bike will run leaner because the lambda probes will compensate for this. There is a definite difference with no cat. I ride my bike most of the year with a cat-bypass, but fit the cat in order to have an mot. It is noticeable how it does not run as sweetly or pull as strong in the lower to mid range with the cat on. I have no idea if it makes more torque or bhp, and frankly don't really care. It does however ride much better Now back on track: - spare key blade for panniers etc definitely best bang for buck since they are so cheap. - keyless filler money well spent for the convenience. - nav mount is a necessity if touring. Navihalter was the best but there is a lot more choice now, so no idea which is best / cheapest. - Comfort seat for rider and pillion. A happy wife is a happy life - Brembo Serie Oro rear disk and decent pads, for a pretty good, working rear brake. - M4 front calipers, for sports bike front stoppers on a pre DVT bike. A no brainer if you like to make progress, especially if 2 up (was glad to see the DVT S got better brakes when it came out) - noisy can and cat-bypass are not really a necessity, more of a nice-to-have. They do get rid of a lot of weight and heat though (getting rid of the cat also reduced the heat effect on the rear brake)
Hi John, No issues with your great comments but: When the bike is accelerating fast, the ECU operates in open loop. The Lambdas do not kick in. They only start operating "closed loop" at constant throttle. Now back on track to the OP's topic.
