Triumph Speed Triple Forums banner
1 - 20 of 42 Posts

·
Registered
Joined
·
2,832 Posts
Discussion Starter · #1 ·
Link

Why is that mesh thing in there? To me it seems it's just distrurbing the flow. Db-killer of some kind?

I'm really tempted to dremel it off.
 

·
Registered
Joined
·
4,658 Posts
Are you talking about the entire perforated tube? It is part of the silencer.
 

·
Registered
Joined
·
5,266 Posts
No Devi it's a mesh across the tube diameter. You reckoned it was some CAT sort of thing.
I have my doubts. Maybe the Annitori guy can ask the Zard factory what it's for.
 

·
Registered
Joined
·
8,252 Posts
The Db killer should be able to be removed with an internal snap ring pliers. Look for a snap ring in the exhaust end of the can.
 

·
Registered
Joined
·
2,832 Posts
Discussion Starter · #5 ·
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.
 

·
Registered
Joined
·
2,832 Posts
Discussion Starter · #6 ·
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.
 

·
Registered
Joined
·
8,252 Posts
:wtf: I'll have to look closer at mine when I get home tomorrow. You would think it would be better flow wise to have it on the bench rather than in the can though.
 

·
Registered
Joined
·
4,658 Posts
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.
 

·
Registered
Joined
·
2,832 Posts
Discussion Starter · #9 ·
So I guess I remove it then. If I go as far as smoothen small irregularities in the headers, I can't leave a big lump like that in there :D
 

·
Registered
Joined
·
2,832 Posts
Discussion Starter · #11 ·
Gr8shandini on trat said it might be to regulate or homogenize the air flow to the O2 sensor. What do ya think?
 

·
Registered
Joined
·
4,658 Posts
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.
 

·
Registered
Joined
·
2,832 Posts
Discussion Starter · #14 ·
Devious2xs said:
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.
That's what I thought :)

Neat! I get to cut some metal! ;D :wrench:
 

·
Registered
Joined
·
4,658 Posts
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.
 

·
Registered
Joined
·
8,252 Posts
Premier, I don't have that piece in mine!!! :wtf:

The welds were a little sloppy in that area so I went to town with the die grinder and burr, all is good now!! :drink:
 

·
Registered
Joined
·
2,832 Posts
Discussion Starter · #18 ·
OK. So it's coming off ASAP :) It's propably a sound baffle, like devi said, to meet the e-approval requirements (EU thing).
 

·
Registered
Joined
·
4,658 Posts
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?
 
1 - 20 of 42 Posts
Top