Exhaust Options,

Message

UpsMan · #1 Post by **UpsMan** » Fri Jun 15, 2007 3:19 am

OK, the time is coming when we have to be quiet and make max power. The series I have been racing (D-23) requires you to be under 99.9 db. My HMF QRS has passed both times they tested, but now the core is broken for the second time and packing is blowing out. I have only been using it 2 months since it was repaired and re-packed by HMF. To me, this just isn't good enough. It is under warrantee and of course they will fix it, but I don't have 2 or 3 weeks to wait for them, I have races every weekend. So, what else is there? Cobradaler was working on some exhaust. I'm not intersted in duals, but his single version sounded promising as long as a quiet core can be used. Any info on it? How about the Black Widow Flow? Is it quiet enough? Anyone using one under mx race conditions and having it hold up? I need something reliable and powerful and durable. And no, I don't think the Ti is going to be quiet enough.

kdeal · #2 Post by **kdeal** » Fri Jun 15, 2007 12:22 pm

The BW Flow Muffler, HMF, & FMF all have quiet core options that should all get you under 99.9db. Brad even has a surprise he may hook you up with as well. He found 5 new Ti head pipes and had Flow mufflers made to fit them. This will give you one of the highest flowing pipes ever made for the Dale and a pretty reliable muffler as well. I believe the Flow mufflers have two or three options for core inserts. Good Luck!

cannondale27 · #3 Post by **cannondale27** » Fri Jun 15, 2007 12:29 pm

If you want Aaen could make you a slipon for your HMF headpipe.Take a day.I think it will pass 99.9db without any core.He does have a silent core or you can use supertrapp discs on it to tune it to whatever level you want.

kdeal · #4 Post by **kdeal** » Fri Jun 15, 2007 12:44 pm

Another interesting option.......

thedeatons · #5 Post by **thedeatons** » Fri Jun 15, 2007 2:58 pm

We just bought a dB meter from Radio Shack because we are dealing with this issue on our upcoming Oregon trip. I have an FMF Ti, Dale original with low hours on it. My friend has an HMF on her Dale. Cdsracer has a Supertrapp with 11 discs in (any less and it wouldn't start well). All of us are way over 100. *The Supertrapp rang in at 104dB, the HMF at 124, and the FMF Ti at 117 with a quiet core. The quiet cores are a joke, and could be made at home for ~$3. I have not tested my FMF Ti without the quiet core yet, but it drowns out the 124dB HMF when they are both "un-cored" and idling next to each other. Oregon's dunes are supposedly 94dB according to the book, or was it 93dB? It doesn't matter, because simple fact is: None of us pass!

*The Supertrapp listed above at 104dB is stock 432, no porting, Boomer style air filter, Moto map.
The HMF listed above at 124 is 450CP, Timbo Gen3 porting, Boomer style air filter, Terminator base map.
The FMF Ti listed above at 117 (with quiet core installed) is 450CP, Timbo Gen3 porting, Boomer style air filter, Terminator base map.

Good luck getting a bunch quieter and still having lots of fun. I think these tracks are ridiculous, whatever happened to"for closed course competition use only"? They need to quit building tracks near subdivisions.....

*Supertrapp dB level corrected at 8:41am PST 6/15 by thedeatons

UpsMan · #6 Post by **UpsMan** » Fri Jun 15, 2007 3:14 pm

How are you doing your sound test? It sounds like something is wrong with your test. The loudest quad I ever heard was only 113db, and it almost made my ears bleed. Are you testing wide open throttle or something? At the races they test at a specific rpm, and it isn't very high, maybe 3-4000 rpms i'm guessing.

thedeatons · #7 Post by **thedeatons** » Fri Jun 15, 2007 3:40 pm

Sorry UPSMAN, I need to make a correction to the above post... Please recheck the numbers.... The Supertrapp was quieter than I originally mentioned.

We are doing the test exactly as Oregon State does the test. You hold the meter 20 inches from the pipe outlet, at a 45 degree angle. Oregon has rules about each specific brand, model about what RPM to test at, most of the sport quads are 3750 RPM. All of our tests were made at IDLE! I called the rangers and they said the Radio Shack meters are accurate and read very closer to theirs, but can be a bit skittish on maintaining the reading as you watch it on screen (quick refresh time). As far as we know we are testing correctly, our quads are just loud man....

UpsMan · #8 Post by **UpsMan** » Fri Jun 15, 2007 4:21 pm

That sounds real similar to the procedure they use here. Take a reading on something that you know is quiet enough, maybe a stock quad exhaust if you have one. I'm curious what your test shows for that.

cobradaler · #9 Post by **cobradaler** » Fri Jun 15, 2007 5:06 pm

QUOTE (UpsMan @ Jun 14 2007, 10:19 PM) <{POST_SNAPBACK}>

OK, the time is coming when we have to be quiet and make max power. The series I have been racing (D-23) requires you to be under 99.9 db. My HMF QRS has passed both times they tested, but now the core is broken for the second time and packing is blowing out. I have only been using it 2 months since it was repaired and re-packed by HMF. To me, this just isn't good enough. It is under warrantee and of course they will fix it, but I don't have 2 or 3 weeks to wait for them, I have races every weekend. So, what else is there? Cobradaler was working on some exhaust. I'm not intersted in duals, but his single version sounded promising as long as a quiet core can be used. Any info on it? How about the Black Widow Flow? Is it quiet enough? Anyone using one under mx race conditions and having it hold up? I need something reliable and powerful and durable. And no, I don't think the Ti is going to be quiet enough.

hey ups the NMOTION cans are available with quiet core and spark arrestors and i can also get 12in cans to make them quieter.

thedeatons · #10 Post by **thedeatons** » Fri Jun 15, 2007 7:52 pm

Normal, audible speech is measured at ~70dB from one meter away. Our meter shows 73-75dB.... My 5 year olds shrill voice shows 80dB (she's normally a loud child)...