Zard slip on modding
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Are you talking about the entire perforated tube? It is part of the silencer.
Yeah. I'm sorry about the bad picture. It sure looks like standard perforated tube. But it's actually a cone about 1 inch deep with the top cut of. The perforated silencer tube is deeper in the slip on. And the Db-killer is on the other end of the slip on.
So it's the purpose of this gizmo that makes me wonder.
So it's the purpose of this gizmo that makes me wonder.
Another pic
The hole in that is only about half an inch wide. The depth is bigger than 1 inch though. 1,5 I think. Don't have anything to measure it with at the moment.
The hole in that is only about half an inch wide. The depth is bigger than 1 inch though. 1,5 I think. Don't have anything to measure it with at the moment.
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The second photo is MUCH better.
It is definately a sound baffle. The design (perforated cone) is to cause the least restriction, but it is still a baffle.
It is definately a sound baffle. The design (perforated cone) is to cause the least restriction, but it is still a baffle.
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I see no reason or need to "regulate or homogenize" the exhaust gasses. The oxygen sensor only works at low throttle positions. There is plenty of gas mixing happening in the header without the "homogenizer". Also, why would Zard feel a need to do this when others do not?
It is a flow restrictor that may help reduce noise by acting like a baffle.
It is likely in place due to some noise or power limiting regulation in the EU. Zard seems to have several versions of their header and silencers depending on where they are sold.
It is a flow restrictor that may help reduce noise by acting like a baffle.
It is likely in place due to some noise or power limiting regulation in the EU. Zard seems to have several versions of their header and silencers depending on where they are sold.
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increase pressure?
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I have never see adding restriction in the exhaust increase torque.
The efficiency of the exhaust system and where it produces torque is determined by velocity and wave tuning - the diameters and lengths of tubing and the angles they are joined in comparison to cam timing and head flow. Adding restriction will not improve low end torque, only limit higher rpm flow.
The old wive's tale about backpressure helping low end torque is a MYTH. It is easy to test. A perfect example of this is the gain in torque experienced when removing the precat/baffle in the 1050 header.
The efficiency of the exhaust system and where it produces torque is determined by velocity and wave tuning - the diameters and lengths of tubing and the angles they are joined in comparison to cam timing and head flow. Adding restriction will not improve low end torque, only limit higher rpm flow.
The old wive's tale about backpressure helping low end torque is a MYTH. It is easy to test. A perfect example of this is the gain in torque experienced when removing the precat/baffle in the 1050 header.
It came off today! 
Baffle removed
Finished version
Clear view to the main baffle
But notice how there's very steep ridge where the baffle starts. And there's also another ridge right in the middle of the going to the baffle. Definitely not optimal for the air flow. I wonder if something could be done about this?
Baffle removed
Finished version
Clear view to the main baffle
But notice how there's very steep ridge where the baffle starts. And there's also another ridge right in the middle of the going to the baffle. Definitely not optimal for the air flow. I wonder if something could be done about this?
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Premier,
In the last photo, it looks like the silencer necks down considerably where the perforated tubing begins. Is it really this drastic?
Is so, this might explain a few things we have seen in the Zard full system dynos. I would still really like to see a before and after dyno chart with the Zard silencers.
Do you have a way to measure the minimum inside diameter through the silencer - using a bent wire or the like?
In the last photo, it looks like the silencer necks down considerably where the perforated tubing begins. Is it really this drastic?
Is so, this might explain a few things we have seen in the Zard full system dynos. I would still really like to see a before and after dyno chart with the Zard silencers.
Do you have a way to measure the minimum inside diameter through the silencer - using a bent wire or the like?
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