Another Exhaust Flapper/Servo Thread

[nickwst4]

I'll be interested to hear objective assessments of the benefit of removing the flapper/servo. Since I mostly ride quite sedately and value the over-run deceleration, I doubt I would benefit from doing this. IMO the exhaust is very adequately loud and characterful on tickover, and beyond that my earplugs dull the exhaust almost completely. No point in confusing the ECU any more than it is already, I think!

By the way, does anyone know when the flapper valve opens? Is it dependent on revs or throttle opening?

Nick

 

[N4teTheGreat]

It's closed under 3k or so I believe and opens above that. I think deleting is by itself won't confer any benefits save for sound, but deleting it as part of tune, assuming the tune accounts for the reduced back pressure at those lower revs, ought to do fine. Removing the entire system when disabled will save weight and some space under the seat as I understand it.

 

[gatdammit]

I imagine it could seize from the heat, but it will seize in the open position. Disabled via ECU flash should be the same as the bypass plug I have. Again, I'm not certain my CEL is related to the servo. My mechanic originally thought it was related to my Lithium battery, which it wasn't.

 

[gatdammit]

It was heavily debated on this forum but, I think we all agreed the flapper was purely for sound and emissions control at low revs. If you care about neither of those things, it's dead weight and a needless moving part. I agree that in stock form, the exhaust note was surprisingly good (on Gen 1's, at least). But when I removed the stock can to hang the Akra, I was floored by how friggin' heavy it was compared to a decent aftermarket pipe. Seriously, Lithium battery and cat back is good for an easy 15 lb weight reduction, maybe closer to 20. Some guys cut the flapper out but, you have to get the old rivet holes welded. I was pretty set on a full header when the opportunity presented itself so never went that far.

 

[saken]

It was heavily debated on this forum but, I think we all agreed the flapper was purely for sound and emissions control at low revs. If you care about neither of those things, it's dead weight and a needless moving part. I agree that in stock form, the exhaust note was surprisingly good (on Gen 1's, at least). But when I removed the stock can to hang the Akra, I was floored by how friggin' heavy it was compared to a decent aftermarket pipe. Seriously, Lithium battery and cat-back are good for an easy 15 lb weight reduction, maybe closer to 20. Some guys cut the flapper out but, you have to get the old rivet holes welded. I was pretty set on a full header when the opportunity presented itself so never went that far.

One reason I got the Project SC setup was that it comes with the mid-pipe + slipon so I didn't have to cut out the OEM flapper assembly. I just take off that part of the pipe and replace it. And I can put everything back to stock for my emissions check. I'm wondering how the Rapidbike is going to affect the emissions check. If it'll throw off the readings enough not to pass. But your right, the flapper is purely just for lowering the decibels for euro 4/5 sound checks. But I assume Ducati accounts for air restriction of the flapper, especially at 3k and under when setting up the stock ECU mapping. Maybe why the bike feels like **** in lower rpms? But this engine probably doesn't run ideally with the factory setup, having such a restrictive air intake and exhaust setup.

As for weight savings, my shorai bat, titanium pipes, and replacing the stock steel handlebars with aluminum, and removing the handguards made huge differences in how the bike handles. I notice it immediately after I removed each one.

I removed the flapper but kept the motor hooked up and then zip-tied the flapper cable to the side of the bike. I've been riding for years like that with no engine light coming on. Then recently I got a CEL. Ducati hooked it up to their computer, and they said the servo motor was a cause, I took it back home and inspected it. I found that the cable had come out of the end of the motor actuator and was just dangling. I will confirm tonight when I get home, but I think this might have caused the CEL. But it's a little confusing to me that the bike senses whether the cable is physically attached or not? I can understand it throwing a CEL with a detached power plug, but the cable is just physically attached, not electronically.
When you turn the bike on, the servo motor actuates, pulling the cable to close the flapper. So if the cable is detached from the motor, I'm wondering if the bike can sense no pressure from the servo motor pulling the cable then throws the CEL?

 

[gatdammit]

Another thing Ducati did with this model for emissions was make the mixture super lean down low. That's the 1st thing a tune corrects and why it gets more manageable down low. Don't kid yourself in thinking this bike will ever be BMW smooth below 3K, however. It will train you to have an amazingly steady and controlled throttle hand, though!

The Evo may affect an emissions test if they compare it to OEM. Never done one so don't know how they work. If you're that concerned, you can get a bypass plug for the Evo. The part # on mine is: F27ADORI-ER (google shows readily available and around $40).

Ya, I left the motor active for years. Got the 'ree-roo' on startup. Again, not entirely sure if my CEL is related, but it did come around the time I removed the actuator. I did a lot of mods around this time and also had a lot of problems I was troubleshooting.

 

[saken]

Another thing Ducati did with this model for emissions was make the mixture super lean down low. That's the 1st thing a tune corrects and why it gets more manageable down low. Don't kid yourself in thinking this bike will ever be BMW smooth below 3K, however. It will train you to have an amazingly steady and controlled throttle hand, though!

The Evo may affect an emissions test if they compare it to OEM. Never done one so don't know how they work. If you're that concerned, you can get a bypass plug for the Evo. The part # on mine is: F27ADORI-ER (google shows readily available and around $40).

Ya, I left the motor active for years. Got the 'ree-roo' on startup. Again, not entirely sure if my CEL is related, but it did come around the time I removed the actuator. I did a lot of mods around this time and also had a lot of problems I was troubleshooting.

So I did some fiddling with the servo motor and rehooked up the cable. The CEL didn't go away. I have a feeling the CEL was caused by something else. I recently did a timing belt change, and the vert cam moved by 1-2 teeth and I didn't notice. When I restarted the bike after the belt change I got the errors CEL. I went back and fixed the cam/timing but the CEL remains so I think it's from that. I will know for sure when my ELM + Melcodiag is here next week and Ill reset the CEL and see if it comes back. I've found a new issue, might be related to the cam timing or fueling. The bike has a slightly weak idle and bogs out and stalls with 1-2% throttle. Stalls @ 0:05 and 1:15

 

[saken]

Update: The stalling issue with low throttle was caused by a loose vert belt. The belt moved by 1 tooth and the timing was off. Most likely I forgot to set the vert cylinder to tdc before setting the tension on the vert belt. Runs better now except backfire on decel is still there but less pronounced. I'm still trying to diagnose my CEL. Pretty sure it's not caused by the servo motor like Ducati told me. I recently went and got the Lonelec cable + Bluescan 2 ODBII to try to read the ecu errors with Melcodiag. I cant say I'd recommend this software at all. It's super fussy and if your windows/pc settings are not set up perfectly or drivers up to date you will have multiple connection issues. I spent the last 3 days going back and forth troubleshooting and asking the melco forums for help and still, haven't got it to work. Finally got it to connect but the license the creator sent me won't work. So my option buttons are still greyed out so I cant reset the ecu errors and clear the CEL. Interestingly, I can read only the first 2 errors but can't reset them and it says Bank 1 o2 sensor 1 malfunction circuit error. If it's reading correctly then I got a bad o2 sensor. Which Ducati didn't find or didn't bother to test..... The dealer is useless.... Anyhow, I know I can test the pins on the o2 sensor with a multimeter to check whether they are burned out. Does anyone know how? Which pin do I ground and which pin # do I test? Which amp or current am I looking for a working sensor or dead sensor?

 

[appliance821]

I may be the only person on earth who replaced his frozen flapper valve so it operates correctly. I camp, and this thing is not so neighbor friendly, so anything that quiets it a bit a low rpm is good with me. Also - yes - emissions - I care - so sue me.