Hi Team. Did a track day on my new to-me 2011 848 Evo. I have spent the past 20+ years racing Motocross but wanted to get back into track days etc., after retiring from road racing 250 Production in the late 90s. Due to my rustiness, I was just working on braking and corner entry using 1 (or more) gears higher for corner exit. Because I was riding down around 4-6000 rpm at the exit, I noticed a flat spot around 5-6k. I was just wondering if this is a result of un-tuned after-market exhausts (my bike came with Arrow slip-ons) or is a symptom of the exhaust solenoid?
I'd go the other way for sure; change down an extra gear and use the top end of the rev range out of the corner. Your 848 Evo should have a quickshifter to grab a gear easily when the bike runs out of revs.
Appreciate the advice, but I'm totally aware of the riding technique required. Per the thread title, the question I had was more about how or what the exhaust solenoid does, and why do people remove it with he solenoid delete dongle... Is that flat spot I'm feeling a tuning issue, a cam/engine issue (i.e. just what it is) or an exhaust solenoid issue?
Yep, sorry about that. I don't think the exhaust valve creates the flatspot but it definitely kicks in mid-range. I've deleted my servo motor and cables and added the servo buddy on my 1098. Works a treat. You don't need to wire the valve open, the fairly strong spring keeps it open for you. I'm also looking at cutting the flap out all together.
Thanks, Dave. I thought it was for working around noise testing but stand to be corrected. However, my question was more along the lines of - Why do people remove it? - What is its effect, and is that the flat spot I was feeling?
I think the valve serves a few purposes. It helps with noise testing as it’s activated around the time noise readings for compliance are taken just as you said. It helps heat the cat up faster when the bike is first started. More importantly for you it helps improve engine torque in the lower rev range. All the above are served by the use of a restriction in the exhaust. Removing the flap valve will improve the performance at higher revs. However, could your system be flat spotting due to an unmatched aftermarket slip on? Maybe put some money into a tuned exhaust, or at the least a Dyno session if you want to keep the valve and the arrow slip on. The comments assume the engine is otherwise running well with no faults?
The exhaust valve is purely there for noise regulation. At a pre set RPM, it closes for a short time, a matter of 300 or 400 RPM. Other than that, it's wide open. That's it. The flat spot comes about from the ignition and fuelling on the stock ECU, again for emissions regs. It's only a Euro 3 bike, so it's not as clean or compromised as a Euro 4 or 5 bike. The DP ECU does a good job of shifting the flat spot as would a tune on a dyno to suit your cans.
What is the start up message on your dash. This will give an indication of what mapping you have in the ECU.
Thank you for the clarification, I wondered as such. Im sorry I'm out of touch with the terms, can you tell me what a DP ECU is? and if it's a separate ECU how does that effect the key coded to the bike?
"DP" .... Ducati Performance. "ECU"..... engine control unit. With the official Termignoni exhaust kits from Ducati, you got a ECU with a different, tuned map on it. No issues with key coding. As Chrisw mentions, when you turn the bike on, what is the message scrolled across the dash? This changes with an ECU swap. It'll give you an idea of what you have, stock or tuned.
