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View Full Version : Does anybody know the DB level of a R4 exhaust?


PhilMoore
05-01-2003, 09:49 AM
If anybody knows, or has had their 400EX with White Brothers R4 slip on and airbox lid removed decibel level measured, please let me know what you got.

I sure hope it is less than 98db.


Thanks in advance!

Phil
hawiianpwr
05-01-2003, 10:03 AM
97db. I found it on the dirtwheels shootout.
http://www.dirtwheelsmag.com/detail.asp?id=181
Heres another shootout from atv news
http://www.atvnews.com/output.cfm?id=30961
PhilMoore
05-01-2003, 10:40 AM
Thank You Very Much!

There is a db limit at the D23 races enforced this year.

Phil
hawiianpwr
05-01-2003, 01:47 PM
Really! Whats the limit?
PhilMoore
05-01-2003, 03:29 PM
98db

It sounds like they are going to be very strict about it.

The sound limit is a good thing imo, but I just bought this pipe, and I thought for some reason it was a 95db rating. I got my facts messed up, so now I am stuck with it. My stock silencer is ruined. (don't ask)
PhilMoore
05-05-2003, 03:38 AM
I got DQ'ed. :(

My exhaust has very low hours on it; less than 6 hours. It is a White Brothers R4 slip on.

It idles at 102 decibels. When I rev up to testing speed, it is 108 decibels! :eek2:

I am really, really angry at White Brothers for even producing a pipe that has virtually no noise supression. This is the first White Brothers pipe I have ever owned (I currently have 9 ATV's and 2 Motorcycles) and I won't ever buy from them again simply because there is no need, in this day and age, for a pipe this loud.

I am disappointed in myself because I had the chance to borrow a DB meter from my wifes workplace, but I thought I could trust DirtWheels. Basically, I wasted my weekend driving down there, and not being able to race becuse my exhaust is too loud.

They said next year the limit will be down to 96db.
UglyMotha™
05-05-2003, 03:50 AM
i only have one question.....

did you have the spark arrestor in?
PhilMoore
05-05-2003, 06:04 AM
Yes, we had to have the spark arrester in. Of course, the White Brothers idea of a spark arrester is a piece of window screen off the back door pinched between the exhaust tip and the main muffler body. Like I said, it is just a piece of window screen, so it provides absolutely no sound deadening properties what-so-ever.