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-   -   100DB Track Limit (http://www.the370z.com/track-autocross-drifting-dragstrip/129332-100db-track-limit.html)

andy_meng1024 12-18-2018 12:39 PM

100DB Track Limit
 
A new local track requires the noise level to be under 100DB directly behind the car at and 95DB on some corners but with a bit distance. I currently have FI LTH and CBE with 18" resonator but it's still too loud, any idea on how to quiet it down without sacrificing power? I also have the side pipe welded to the muffler to reduce the drone at about 3k rpm, but that doesn't really do much at high rev. Thanks in advance.

gomer_110 12-18-2018 07:04 PM

How the hell are you over 100dB with that setup? I have that same setup and consistently come in around 93-94 dB. Maybe try adding some turndowns on the tips that are pointed down to help quiet it down a bit.

yaoxiao4 12-18-2018 08:47 PM

thats crazy, granted i dont have the FI LTH but my FI CBE (also 18 res) doesnt even break 90db on Laguna Seca

andy_meng1024 12-18-2018 08:49 PM

Quote:

Originally Posted by gomer_110 (Post 3807190)
How the hell are you over 100dB with that setup? I have that same setup and consistently come in around 93-94 dB. Maybe try adding some turndowns on the tips that are pointed down to help quiet it down a bit.



What RPM did they use for sound level? The local track asks me to rev to 6k.


iPhoneTapatalk

gomer_110 12-18-2018 09:00 PM

I do autox with SCCA. Generally they setup the sound meter along the course at a point where most people will be near redline. I'm sure I've been measured everywhere from 5500 to 7600 rpm.

Do you know what the settings on the sound meter are. Most have a peak capture mode along with an averaging mode. Averaging mode is what most organization use because peak basically screws everyone. I've see bone stock 911 GT3's hit 100 when measured in peak mode.

Easiest first attempt to get quieter would be to get some 90° ductwork elbows that will slip over the exhaust tips and use hose clamps to secure them in place. Make sure they are pointed down at the ground. This should help noticeable. It won't look pretty but won't lose performance and they can be removed after the event.

Elmo370z 12-20-2018 09:01 PM

Thank god I live in Florida. Car to loud for the track is ridiculous

Rusty 12-22-2018 02:19 PM

Quote:

Originally Posted by Elmo370z (Post 3807664)
Thank god I live in Florida. Car to loud for the track is ridiculous

A lot of tracks are like that now. :(

gomer_110 12-22-2018 04:00 PM

Quote:

Originally Posted by Elmo370z (Post 3807664)
Thank god I live in Florida. Car to loud for the track is ridiculous

I would normally agree with you but the fact is there's always those one or two aholes that show up with a straight piped POS that is loud for the sake of being loud. These jacka$$es are the ones that have ruined it for the rest of us.

Rusty 12-22-2018 04:11 PM

Quote:

Originally Posted by gomer_110 (Post 3807943)
I would normally agree with you but the fact is there's always those one or two aholes that show up with a straight piped POS that is loud for the sake of being loud. These jacka$$es are the ones that have ruined it for the rest of us.

You ever get passed by a NACRAPER during a track day? Fvcker's will make your ears bleed. :eek:

gomer_110 12-22-2018 04:46 PM

For me it's the miatas and civics that show up at autox with straight pipes that argue putting a muffler on would kill their power.

Spooler 12-22-2018 09:21 PM

Quote:

Originally Posted by gomer_110 (Post 3807950)
For me it's the miatas and civics that show up at autox with straight pipes that argue putting a muffler on would kill their power.

What power? LOL

gomer_110 12-22-2018 09:40 PM

Precisely their argument. When they only make ~100 hp, giving up 5 hp for a muffler is a 5% drop in in power.


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