Dr D Exhaust 07 yz450


9 replies to this topic
  • pbviking

Posted December 17, 2009 - 08:31 PM

#1

Anyone know the db level on a SS DR D exhaust? What if you add a quite core? I need to get the bike down to 96db. Thank you for your help

  • grayracer513

Posted December 17, 2009 - 09:31 PM

#2

DRD states that their pipes, freshly packed, will pass AMA sound tests at 96db.

  • pbviking

Posted December 17, 2009 - 09:40 PM

#3

thanks grey:ride:

I am assuming this is without the quite core? Did you find on there website?

http://www.dubachrac...&products_id=40

  • grayracer513

Posted December 17, 2009 - 10:06 PM

#4

Yes, that's from their site, and refers to the pipe with no inserts. But passing AT 96 with fresh packing does leave a little room for variances, which could work against you.

  • racerxx276

Posted December 17, 2009 - 11:05 PM

#5

I tried to pass 96 at a WORCS race with a newly packed dr d on my YZ450f. Had to put the quiet core in to pass.. The sound test was done by the forest service not the usual FMF guy. I blew 99 without it! Don't know how accurate the forest service guys are though....

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  • pbviking

Posted December 18, 2009 - 12:10 PM

#6

I tried to pass 96 at a WORCS race with a newly packed dr d on my YZ450f. Had to put the quiet core in to pass.. The sound test was done by the forest service not the usual FMF guy. I blew 99 without it! Don't know how accurate the forest service guys are though....


Ouch

That is what I am afraid of. Did you notice any difference with the quiet core in vs out. Power, sounds, or?

  • Wes Woodin

Posted December 19, 2009 - 12:06 AM

#7

I tried to pass 96 at a WORCS race with a newly packed dr d on my YZ450f. Had to put the quiet core in to pass.. The sound test was done by the forest service not the usual FMF guy. I blew 99 without it! Don't know how accurate the forest service guys are though....

yeah, no way to pass with freshly packed muffler. I heard if you cut out the airbox in certain areas it will help. I had a pro friend that got stuck running a stock silencer once, due to him not passing sound check.

  • coreyl

Posted January 01, 2010 - 11:35 PM

#8

better safe then sorry get, i would get the insert just to be sure you will pass the test

  • pbviking

Posted January 02, 2010 - 07:47 AM

#9

better safe then sorry get, i would get the insert just to be sure you will pass the test


true but i am hearing that with the insert the bike is still very loud 97-98 dbs...

At least that is how I read into the dr d system

  • coreyl

Posted January 02, 2010 - 02:25 PM

#10

there is a full system on ebay now that has the quiet core included with the auction





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