Hey thomez how loud is your exhaust?

Message

crawlr · #1 Post by **crawlr** » Wed Mar 10, 2004 10:01 am

I keep reading how quiet your exhaust "might" be but without numbers I'm not willing to take the chance. I got a db meter and started trying different things to get quieter and so far I can't get below 100db. I started at about 106 so it's getting better but I need 96 to be legal in California and I'm running out of ideas for my current setup.

Get one of these and give us some real numbers. This is getting to be a serious subject with more areas, and now some races, requiring a low noise level and Cannondales being so **** loud. If you can show that your exhaust can pass the test without killing the performance I think it would be a great selling piont and I would definately buy one.

The procedure for the test is explained pretty well here

Also if anyone has any real numbers on any other exhaust on a Dale lets hear 'em. I've heard an HMF without the quiet core and I can't imagine they can be brought down to legal limits let alone the 92db's that they claim. I ordered a quiet core from them to try in the White Bros silencer I have now but I haven't had a chance to modify it to fit yet. I'll post the results when I do.

Derno24 · #2 Post by **Derno24** » Wed Mar 10, 2004 2:45 pm

I don't live in California, but I know for a fact that most of these sound readings are going to be tough with any exhaust. The external surrounding sound and the persontesting can have huge impacts on the results. I was wondering what weighting are you using for the test? I don't mind testing my HMF pipe, but what I may get may be way different than what you get. I have seen as much as a 6db swing Based on who runs the test.

I am trying to help. You may want to post how the california dunes test in particular. How they do it when you are in person.

thomez · #3 Post by **thomez** » Wed Mar 10, 2004 2:50 pm

Fair enough! On sale for $50 I think we can swing that for the good of our customers out west. I'll get one ordered.

Here is good news, you can come see them in person and even test one out in early April! www.socaldale.com - come on out and ride with us and take one of our exhausts for a spin. If you like it we'll bolt one on your bike on the spot and get the mapping tuned too. Fair enough?

I understand the might syndrome and I agree that you should have concern. I've seen other exhaust companies dodge the subject time after time when questioned on forums such as this. We'll buy the meter, do the test, report results with no BS! If we don't pass I'll tell you we don't!

Thanks for making this a priority to get a meter. Keep an eye on the forums for results.

thomez · #4 Post by **thomez** » Wed Mar 10, 2004 2:58 pm

Update - I ordered one. Think I can write this off my taxes? :rotf

Derno24 · #5 Post by **Derno24** » Wed Mar 10, 2004 4:59 pm

I still think that #'s won't help unless someone gives you exactly how they do it at that dune. There are alot of external factors that can change a db reading. Even air density has an effect.

thomez · #6 Post by **thomez** » Wed Mar 10, 2004 5:07 pm

I think if we follow the same procedure that they follow there, which I can find out, that we can give a good estimate. It will be far better than nothing, I'm sure. We shall see the results.

Derno24 · #7 Post by **Derno24** » Wed Mar 10, 2004 6:13 pm

I know that you are trying to duplicate what is in writing. What I am saying is someone who has been through a sound check should tell you exactly how the guy did his quad/bike. This way when you do your test you can be as close to accurate as possible. You might even be able to give suggestions for temporary fixes for db levels. Alot of time what is practiced on site is different from the way they write it in the books.

Trust me I am not trying to squash ideas just help make them better.

haydug · #8 Post by **haydug** » Thu Mar 11, 2004 1:51 am

At the last GNCC in florida, my HMF went through tech at 104db. It is a fairly new pipe, with around 6-8 rides on it.
I now have an exhaust on my bike that a member on this site built, and all I can say it WOW!! :wow

Can you say quiet, this guy lives out west, where they enforce the sound restrictions. I have had it laying here for awhile and have tried the headpipe, but never the full system until today. I had to send my HMF to a customer so he can ride this weekend until his gets here, so what better time to try this out.
I bolt it on and take a spin through the field, and this thing rips. This is by far the best exhaust I have ever ran on a bike, look for a full write-up with pictures very soon. As for the member, maybe he'll chime in and let us in some db tests or what he knows about it.
I should have a full review of the FT exhaust sometime in the future, but they must be on backorder at the moment. I'll keep you all posted.

pdavis · #9 Post by **pdavis** » Thu Mar 11, 2004 2:07 am

at palatka, i was at 104db with a brand new (less that 4 hrs) big gun

crawlr · #10 Post by **crawlr** » Thu Mar 11, 2004 3:18 am

The testing procedure they used on me was exactly like the one explained in the link on the first post. I had to warm up the quad and park it in an open area so nothing was within 16' in any direction. Then one guy held a little tach that works off the vibration of the motor against the clutch cover and the other guy held the DB meter at a very specific spot behind the pipe. They reved it to about 4800rpm which is what they estimated half the max rpm to be based on the bore and stroke.

The proper way to hold the db meter is 20" away from the pipe, at a 45* angle with the tip facing to the rear and 90* to the pipe. This didn't make any sense to me til I actually saw it so I'm including a pic of how it looks. They even had the 20" piece of string on theirs. (but he was just holding the other end next to the pipe. I had to tie it so I could hold the camera

)

These guys were well trained for this and i'm sure every test they do would come out close to the same. I've been testing mine in the front yard using my laptop for the rpm reading and my numbers are close enough to theirs to make me believe it is accurate.