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V8titanpwr

M4 exhaust issues.

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V8titanpwr
Is anybody else having the issue where the baffle is rattling around? I haven't touched the screw for the DB killer but it's vibrating like crazy.

Keep the rubber side down and the shiny side up.

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Tark
I've not noticed it, but I've not checked mine either. I'm guessing you checked to see if the screw's tight?

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V8titanpwr
Yeah the screw won't tighten any farther. I'll contact M4 today and see about a solution. You can here it idling or at speed, sounds like a metal rattle.

Keep the rubber side down and the shiny side up.

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aeisan
I have been running mine without the dB killer in, but I actually just put it back in last night for a longer-term comparison of the sound and power feel. I've not noticed any rattle from it, but if I do I'll let you know.

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V8titanpwr
Update: Got everything figured out. The bolt had vibrated loose somehow, the problem was that it just wouldn't tighten any further so I ended up stripping the head. Got the allen bolt out and just replaced it with a hex head so now I can just use a wrench which is much easier.

Keep the rubber side down and the shiny side up.

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aeisan
Glad to hear you got it taken care of.
 
After a few weeks with the dB killer out and a little over 200 miles this weekend in some BEAUTIFUL weather with it in - I'm convinced I'm leaving mine in. I did like it louder when it was out, but the sound note and performance were much better with it in.

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GAZ
Yeah even in the 15 minutes I had the DB killer out I could feel the performance drop significantly.
Would this be due to the fact of no fuel controller? I would think DB killer out would perform better. 

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aeisan
Yeah even in the 15 minutes I had the DB killer out I could feel the performance drop significantly.
Would this be due to the fact of no fuel controller? I would think DB killer out would perform better.
Most likely, yes.  It's all about the air-to-fuel ratio (AFR).  You need a balanced system of intake, exhaust and fuel for optimum performance.  They ideally should each be tuned for each other, or at the very least the fuel should be tuned for the amount of air being realized.  
 
You could have more flow through your exhaust than the intake is able to feed, which is common when you add an aftermarket exhaust and do not modify the intake, but that just means the intake will restrict the system and the exhaust is potentially not being used to its full potential.  The AFR can still be dial in for the most optimum performance with this setup, but may not make as much power and/or torque as a system with better intake AND better exhaust AND a fuel mapping to optimize them.  
 
So, without a new fuel mapping the flow on the exhaust with the dB killer out would most likely be too high for the stock fuel mapping, resulting in lean AFRs and as is being reported - less torque due to less than optimal AFRs.
 
The M4 with the dB killer in seems to closely match the flow of the stock exhaust, hence less of a need to adjust the fueling.   

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Cruizin
Remember that the M-4 is a cheap exhaust, too. Lowest price option is often not the best option. I have one on my FZ-09 and the damn housing is creaking already.
 
I'm getting a Marthy soon. To me, it's the best value exaust and priced right in the middle.

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valhalla
Remember that the M-4 is a cheap exhaust, too. Lowest price option is often not the best option. I have one on my FZ-09 and the damn housing is creaking already. 
I'm getting a Marthy soon. To me, it's the best value exaust and priced right in the middle.
Huh?
The FZ-07 motorcycle is the "lowest price option" AND the "best option."
And in my view, same could be said for the M4 slip-on exhaust.
 
 
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aeisan
Remember that the M-4 is a cheap exhaust, too. Lowest price option is often not the best option. I have one on my FZ-09 and the damn housing is creaking already. 
I'm getting a Marthy soon. To me, it's the best value exaust and priced right in the middle.
I don't agree with this at all.  I think the M4 is of very good quality.  I would say it is anything but cheap.  Their engineering is top tier and race proven.  The quality - from the welds on my mid-pipe to the rivets on the silencer - is very nice.  I was quite impressed when I unwrapped mine (and I've used/installed a fair share of slip-ons and full systems in my day).  
 
There are some things you have to consider before comparing the M4, or any slip-on really, to a full system.  
 
First, you are not talking apples to apples.  The fact that you keep the stock head pipes alone hinders the performance gains - both with respect to weight savings and gas flow - versus a full system.  This is also a large reason they cost less than a full system.  You only get half the system.  Plus, so much of the flow characteristics of a system is determined by the head tubes, more so than the mid or the silencer chambers.  
 
Second, primarily due to the reason above, it's commonly known that a typical slip-on will not provide much in terms of performance gains other than due to the weight savings.  That's not why most people buy them.  Most guys I know looking for a slip-on typically want it just for the sound and lower cost than a full system.  If you want the better performance gains, it goes without saying that you get more if you pay more for a full system.  
 
In addition to that, a third difference between a slip-on and a full system is commonly having to re-map the fueling for the full system, as it brings with it much more flow like was mentioned above.  Again, this contributes to the higher performance gains of a full system, as well as the higher cost.  That's not to say re-mapping the fueling will not have an impact with a slip-on - it often will, and a higher performance gain than the slip-on itself - but you will not benefit from a re-mapping as much with a slip-on as you would with a full system.  
 
So...  To recap...  
 
Is the M4 option cheap?  Not by any means.  
 
Lower cost?  Certainly.  
 
Best?  That's highly subjective - but for me, yes it was the best option for reasons above just looking at torque and HP curves.  
 
 
 
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