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CRD DIY STUBBY - power loss?

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Evening thumpers.

My bike, 2004 E, came with a full CRD absolute performance system. Lovely system although quite frankly it made a rubbish sound and was quite quiet. Made to be enduro legal I believe, so 91dB.

With the intentions of making it a little louder I decided to modify the end can. I may have got a bit carried away and I ended up turning it into a full on CRD ABSOLUTE STUBBY!!

I think it looks the part, and it weighs nothing!

But...

It's caused a loss in bottom end power.

What can I do to rectify this? The sound is nice and it is deeper.

Have I ruined the exhaust or can it be fixed?

I'm currently running the standard e system while I investigate.

Cheers.

ImageUploadedByThumper Talk1399752252.809328.jpgImageUploadedByThumper Talk1399752266.051774.jpgImageUploadedByThumper Talk1399752285.802199.jpgImageUploadedByThumper Talk1399752298.052547.jpg

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Can you adjust the exit diameter, maybe big washer or end cap insert?

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It still has a baffled section inside it. Do you think it's a back pressure problem then?

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The bike pulling ok at the bottom , but the power doesn't feel as strong.....Is this correct..?

 

Any difference with the air box door removed..?

 

Is the airbox snorkel removed.?

Edited by Craigo 485sm

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I have one of these in titanium, love it. The sound too!

Does the muffler still have packing? mine lost bottom end when the packing wool was gone

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I shortened me MRD exahsut from 14 to 12 and did not notice any bottom end power decrease,  i think it looks good now that way you did it. 

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Craigo you're correct. I only did one test run as it was getting late.

But yes it ran and rode fine but there was a distinct lack of torque low down!

It doesn't have any wool now, it does have a baffle part inside but perhaps this isn't holding enough back pressure now.

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And yes the snorkel is removed. Felt noticeably quicker with the e system back on.

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Craigo you're correct. I only did one test run as it was getting late.

But yes it ran and rode fine but there was a distinct lack of torque low down!

It doesn't have any wool now, it does have a baffle part inside but perhaps this isn't holding enough back pressure now.

 

mate, If it still runs crap after you re do the packing I reckon you have F#%ked it ....

And yes the stock E system is a very good design...

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I'll repack it and see what changes I can make to restore the back pressure (I assume this is the reason for the initial bottom power loss!)

Maybe as stated earlier reducing the baffle size with a welded washer would help.

Now to drill those rivets..

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Update, a good one!

 

So today I did some back to back testing with the stubby CRD and the E exhaust

 

My initial feelings were confirmed, the CRD had a lot less torque lower down than the E exhaust.

 

I went back to the drawing board and deconstructed the CRD again. Using the baffling and Glass Firewool (or whatever its called) I modified the size and packed it into the stubby.

 

This gave it a deeper more thumpy sound and really improved the performance. I am very pleased!

 

I will admit that performance wise it still doesnt pull like the standard E system does, but I put this down to jetting. Hopefully the stubby CRD can be jetted to out perform the E system.

 

 

After rigorous testing.. see pic...  nothing has fallen apart and things are going well.

 

 

The CRD now weighs no more than 4-5 kg, its half the weight of the E cannon.

 

Let me know what you guys think. I'm going to give it a good polish and tidy up the rivets soon. 

 

Cheers.

 

image_zps2af6b2f3.jpg

 

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