Can my T-4 pipe pass the calif. 96 db test??

7 replies to this topic

Posted January 26, 2003 - 05:18 PM


is there any mod to make my pro circuit t4 pipe pass the calif.sound test.of 96 db?? help I am willing to modify it or buy a smaller end cap and quiet core insert but when I called Pro circuit they said I needed to buy thier new improved silencer coming out next month?? Any Ideas??Jim...

  • jim-in-so-ore

Posted January 27, 2003 - 08:38 AM


The only way the T4 will pass is if you don't start the bike.


Posted January 31, 2003 - 06:13 PM


I am not sure but you might try a quiet core with the
1.5 inch end cap to see if 96 is possible??? any other idea?

  • Dan_Lorenze

Posted February 01, 2003 - 11:34 AM


I have the same bike and pipe, I want to say you're at 102db. The quiet core will drop it a few dbs but I don't think enough... The quiet core is so restrictive that it makes riding no fun at all..... Try to borrow a pipe for the ride.

good luck..


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  • Muzza

Posted February 01, 2003 - 01:58 PM


A T4 will never pass a noise test until PC put in some serious work.
I know people who have bought them, ridden once and then sold them, only to have the second owner do the same.

In Oz, to even race MX you must meet the noise test requirements.
There are some pipes they won't even bother testing.
Top of the list is the T4.

The whole noise debate issue has been a done deal in Europe for years.
Guess where most of the quieter pipes that still give you some serious performance come from?

Shame on you Pro-Circuit. :)

  • dp400

Posted February 01, 2003 - 05:09 PM


My T4 on a 450 KTM with quiet core ran 98 dbs. There is a few things you can try. One is have a turned down end piece made - the sound is directed to the ground - a friend and I were riding ( both KTMs w/ T4s) his had turned down end piece - I thought he had his stock pipe on - said no loss of power. Another is something an XR guy posted - use JB Weld on your screen - cover from the tip up 1/3 - 1/2 way - the sound is disbursed to the sides more - I have not tried it but it may work. :)

  • Rainman_WFO

Posted February 02, 2003 - 12:16 PM


No matter what you try, the T4 will NOT pass unless you just look at it with the bike off.

I am using the stock silencer with the Baja Designs baffle insert and I tested yesterday @ 94 db. Power does not seem to be seriously affected either,

Rainman :)


Posted February 05, 2003 - 07:09 PM


I guess I will have to put my stock muffler back on and suffer the weight difference of 3 pounds. thanks for the info, jim.


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