Decat - Noise Levels - Thoughts??

[RossHarper]

I'm not saying your wrong, only what BMW told me.

This is a picture of a Motorcycle CAT. http://image.made-in-china.com/2f0j00aBjtGHWJqRzg/Motorcycle-Catalytic-Converter.jpg

When I cut my exhaust myself to fit the Dan moto decat pipe, I made the cut where shown on below picture by the red line. The CAT material filled the area shown by the blue box and continued past the red line up to the blue line, leaving most of CAT box empty
http://s21.postimg.org/dwbmvm4pz/BMW_S1000_RR_stock_exhaust_2.jpg

I did look at the ARCS system, but thought i'd try the Dan Moto one first considering it was £97 (inc del at that times exchange rate of course) and exactly the same thing.

 

[RossHarper]

So if you make the cut in the same place for the ARCS decat pipe and left the amount of CAT which is on the header side of the cut then that would help reduce noise levels to some extent

 

[fatbob]

When I cut mine it had to be cut in a specific place if you wanted to use the sleeves provided. The sleeves enabled it so you could still put the cat back on if you liked

 

[Hopper]

MHP can make you a baffle. You'll need it for any UK TD's you thinking of doing. The short cans with a decat are stupid loud...

 

[Hoops]

I will have to take a look at this ARCS thingy me jig then!! Thanks again for all the info chaps.

 

[RossHarper]

Yea the Dan Moto didn't give any way of putting the old CAT box back on. But with 2 minutes of thinking it through before cutting, I can add mine back to the bike using some clamps that me and the old man fabricated.

The clamps probably wouldn't hold up to serious use but are fine for adding cat back in, riding to get MOT and riding home.

 

[bananaman]

I'm not saying your wrong, only what BMW told me.

This is a picture of a Motorcycle CAT. http://image.made-in-china.com/2f0j00aBjtGHWJqRzg/Motorcycle-Catalytic-Converter.jpg

When I cut my exhaust myself to fit the Dan moto decat pipe, I made the cut where shown on below picture by the red line. The CAT material filled the area shown by the blue box and continued past the red line up to the blue line, leaving most of CAT box empty
http://s21.postimg.org/dwbmvm4pz/BMW_S1000_RR_stock_exhaust_2.jpg

I did look at the ARCS system, but thought i'd try the Dan Moto one first considering it was £97 (inc del at that times exchange rate of course) and exactly the same thing.

Ah, you could well be right then. I've not been into the box to see how much is filled. My pic shows how much is in the headers, the cut position allows the box to be re-fitted if necessary with the sleeves provided with the purchase.

 

[Niven770]

Not sure where the Cat starts and finishes but the "big box" certainly isn't empty, it weighs a bloody ton.

The cut points for Cat removal are different on pre / post 2012 models as the pipe between the "Cat" and header is tapered on the 2012 and parallel on the 2010/11 (pic above is 2010/11).
ARCS for 2012 does not include sleeves to refit Cat due to the tapered pipe.

Regards
Davy

 

[fatbob]

This is my adjustable dalek baffle for my arrow system , I can adjust the cap till it sounds like a car

 

[Hoops]

This is my adjustable dalek baffle for my arrow system , I can adjust the cap till it sounds like a car

Thats awesome mate - clever design.

 

[thompsp]

MHP can make you a baffle. You'll need it for any UK TD's you thinking of doing. The short cans with a decat are stupid loud...

I'm planning on fitting a decat pipe this weekend, which will mate to the usual short stubby BMW-supplied Akra. In anticipation of this and after reading the comments above, did any of you (that have done the same thing) find or make a db killer for it? If so, did it choke the power out of it?

If it is still too loud, then I'll just have to replace the end can with a longer one ...which I don't really want to do

 

[Hoops]

I still havent done anything yet - BUT im still very much wanting more noise and i want to remove the cats - im looking at a decat pipe but im most interested in the ARCS system because it means i can REFIT the cats as and when needed - i dont like the idea of cutting the cats off and it being a permanent thing.

 

[RossHarper]

Hoops, even with the £100 Dan moto decat link, you can still put the CAT back on afterwards.

 

[thompsp]

Yes, in my apprehension too, I have bought a another set of headers and the decat pipe fitted to it, so just in case I want to go back (especially when I eventually sell the bike). I'm definitely doing it though and I'll let you know my thoughts on the sound, power delivery change, weight, temperature loss and thottle feel changes that it should bring, plus what I might do next (to fix any big issues).

I still havent done anything yet - BUT im still very much wanting more noise and i want to remove the cats - im looking at a decat pipe but im most interested in the ARCS system because it means i can REFIT the cats as and when needed - i dont like the idea of cutting the cats off and it being a permanent thing.

 

[MickyC]

Bought a Voltcraft SL-100 decibel meter, with the standard can and Danmoto decat it measured 95dB at tickover and 113.6dB at 11000rpm, bugger!

 

[bigdave139]

I took mine to Bedford today... MSV test at 7000rpm (for a 4stroke 1000cc) at all their tracks, and with my decat and akra stubby it read 110.9 on their kit.
As MickyC said... Bugger!

 

[DJUK]

I'd love to hear how loud they actually are with a stubby akro exhaust. About to buy myself some headers on the weekend and ordered a danmoto decat pipe. Just abit nervous about how loud it's going to be. Even though my old bike had a not for road use exhaust that was loud...

 

[RossHarper]

http://www.youtube.com/watch?v=WbSOoK6Jj6M

Thats a vid of mine. Taken on my phone so not amazing quality and it was awhile ago but if memory recalls I think i only took it to 10,000rpm in that vid.

 

[DJUK]

Yeah but the problem is (like you've pointed out many of times I may add) that you can't really tell how loud it is by watching a video. Need to hear it in person.

 

[RossHarper]

Yeah but the problem is (like you've pointed out many of times I may add) that you can't really tell how loud it is by watching a video. Need to hear it in person.

It's true, the video doesn't do the noise level any justice.