This must be a problem for everyone these days. When I got my car it had two
round boxes in each pipe. The middle boxes were replaces with fat ovals to
make a
db limit. On the Isle of Mann I bashed them on a bump and put on straight pipes
for the rest of the events. To drive home again the repaired silencers went
back
on but didn't seal properly and now make more racket than the straight pipes...
I spent my drive home - with ear plugs - trying to think of ways to make boxes
with straight pipes for racing but some kind of valve to perforated and baffled
byepass system within the same box. I've also seen cars with tailpipes with
what
looks like an adjustable number of 'plugs' in the end to fine tune noise level.
Anyone managed to build an easily switchable system ?
David
RodPolentz@aol.com wrote:
> In a message dated 9/20/1998 1:22:04 PM Pacific Daylight Time,
> gregmogdoc@surfnetusa.com writes:
>
> > I understand that the DB limit wil be the same as last year, 103 for the
> > loudest classes that run in the middle of the day , 101 for the intermediate
> > groups and 99 for the nearly "street stock" group that runs first in the
> > morning.
>
> I believe that would be 90dbA for the "stock" classes. They run early in the
> morning and late in the afternoon. My recollection is that it is 90dbA from
> 8:30 a.m. to 9:00 a.m. Then it's 101 from 9:00 to 10:30, 103 dbA from 10:30
> to 3:30, 101 again from 3:30 to 4:30 and 90dbA from 4:30 to 5:00 p.m. No cars
> on track before 8:30 a.m. or after 5:00 p.m.
>
> Rod Polentz
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