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Here you go but plus headers…
Not all wsbk bikes have long exhaust including the factory team in 2021.
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What exhuast
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Here you go but plus headers…
Not all wsbk bikes have long exhaust including the factory team in 2021.
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I’m interested to know the function of the exhaust flap in the spark wsbk exhaust as well as the stock exhaust for that matter.
Is it for back pressure to allow more low end or for sound reduction at moderate speeds? Or both?
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Is it for back pressure to allow more low end or for sound reduction at moderate speeds? Or both?
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Stock exhaust is for noise emissions.
WSBK/MotoGP, it's for back pressure - increasing midrange.
WSBK/MotoGP, it's for back pressure - increasing midrange.
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Interesting how spark have incorporated it on a production system then.
I’m guessing their proprietary tune manipulates the stock exhaust valve motor, optimizing performance to suit.
[mention]Steven31371 [/mention] this might be something to consider when programming your woolich tune.
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Almost all the aftermarket tuners eliminate the code for the missing exhaust servo.
The reason you go with a longer exhaust is that if set up right it aides in scavenging, meaning one side creates a vacuum in the other side staggered by cylinder firing order that help evacuate exhaust faster…power is about air in air out…but if the system is too open you lose midrange torque…torque needs some resistance in the airflow to occur….by using a longer pipe you increase scavenging and crest some airflow resistance that will creat torque earlier in the power curve, but Torque also HP to rise earlier in the power range and reach top out earlier.
I’m guessing that these guys are using a shorter pipe to gain top end power but using a flap to create some airflow resistance and therefore more torque earlier in the power band, and then open it up for top end power.
Another solution is to change the final drive on the sprockets to get more torque earlier in the power curve…which I’ve done with my 15/44 tooth setup.
So I’m fine with a more free flowing shorter exhaust that gives more power up top, because I’ve heated mine to give me more pull at the lower rpm.
Question though, is the flap on this exhaust servo activated?…if so I’ll have to find my servo hahaha
Or is it pressure activated?
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Exhaust arrived today.
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Looks nice! Good welds.
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Damn! That system looks incredible!
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I know about scavenging and exhaust pulse tuning. That has more to do with manifold length and collector placement, not exhaust length.
My point about the spark exhaust is that it looks like it has a valve on the left side outlet, and if that's the case then the servo is surely going to control it. I mean that the ECU should be taking advantage of this servo (exhaust flap control) when tuning for power if that's its purpose.
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Beautiful piece you got there craig.
Can you confirm if there's a valve in it?
Can you confirm if there's a valve in it?
I am curious to find out if the new undertail Akrapovic will fit on the older models.
Ducati’s website says it’s for 2022 only, but I am hoping that is because of the upmap key is specific for the 2022 ECU and that physically it all fits.
Ducati’s website says it’s for 2022 only, but I am hoping that is because of the upmap key is specific for the 2022 ECU and that physically it all fits.
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I’m inclined to think that it fits, there shouldn’t be a physical reason that it doesn’t. It would also make sense financially for Ducati as the apparent motivation to create this exhaust is to meet track regulation sound limits, so retrofitting older models could be a considerable market share. I’m sure it also stemmed from previous model complaints.
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I have a Spark.it exhaust but for a different bike. It had the mechanism to keep the exhaust servo but it was a dummy set up, no actual shaft that gos into the tubing and no actual flapper. Not sure if that's the same case for the big boy exhaust but that is what I cut off mine. These are just tack welds to a bolt that spins inside that barrel, noting actually gos through into the pipe.
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Oh, that’s quite mystifying!
It might be the case for this exhaust too, as there’s no mention of an actual valve on their website or anywhere else.
Could it be provisional? I’m utterly perplexed!
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It might be the case for this exhaust too, as there’s no mention of an actual valve on their website or anywhere else.
Could it be provisional? I’m utterly perplexed!
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Exhaust servos are ECU controlled. The servo operation has to be “tuned” to the application mechanically and electronically. You’re not going to buy a “real” SBK pipe with a servo system and plug it into your V4R. The “real” SBK pipes are designed to work with the MM and Motec engine management systems and are tunable within the engine parameter programming.
The stock bikes system is electronically “fixed” to the programming in the stock ECU. It’s not a tunable system. Selling a SBK replica pipe with a dummy servo is a little weird. Even if it was operational it would need programmable ECU intervention as it flows differently than the stock pipe and you’re not doing that with the Siemens Continental ECU.
The stock bikes system is electronically “fixed” to the programming in the stock ECU. It’s not a tunable system. Selling a SBK replica pipe with a dummy servo is a little weird. Even if it was operational it would need programmable ECU intervention as it flows differently than the stock pipe and you’re not doing that with the Siemens Continental ECU.
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Are you sure about this?
The M4D flashes are able to turn the servo off. There could be a way to configure activation parameters as well, unless your certain it’s fixed.
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Nope, not sure because I have not actually installed or programmed a tunable exhaust. I do have a MM kit and a Motec kit going on the bike I am building now. The information I posted came from Motec and I paraphrased. Im sure the flash enables you to turn the servo off as a lot of guys are running aftermarket pipes and they want to delete the servo.
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Precisely why you don’t see servos on all the aftermarket pipes, the Mfg understands that the buyer probably doesn’t have the rest of the “system” to make that work correctly. If you do want to incorporate servo technology then you buy the MM kit and the race pipe with the servo and the software and get after it.
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