Exhaust Turn-Downs for Track?

yousefnjr · 07-20-2017, 02:08 PM

I was at Laguna about a month ago and got flagged for noise. They have a 90db limit, and got me at 98.5

I saw a handful of cars there with exhaust tips pointed to the left (away from the measuring booth) and I want to try something similar.

The tips I saw were all metal, and I'd really like to have some in silicone just for easy install/removal. I spent a long time looking online for the highest rated temp silicone I could find and came across these. They're made with Nomex and good for ~500 degrees F. I measured my tips after a drive and the highest reading I could get was in the 240 degree range. I assume the gas coming out at WOT gets hotter than that, but I have no idea how hot. Anybody know? Running full catless. Semi-related to that, fuel is supposedly bad for these, but I figure a few sessions here and there should be ok

Ordered 4 of them, they slip right on the stromung 3" tips. They're a little thick though, will take some massaging to get them well fitted.

Will update if the Z becomes a massive fireball

ZAR4MC · 07-21-2017, 01:47 AM

PLS, Take a video of the sound with them on all 4... want to see how the exhaust note changes

Finnegan · 07-21-2017, 07:54 PM

They look like they're on fire already!

Best solution I've seen is using the 991.1 GT3 exhaust system valves plus Raspberry Pi and GPS to geofence the sound station and go into stealth mode through that spot.

Sans the hardware this looks like a good bet!

3002 tii · 07-21-2017, 09:22 PM

I know they're functional but man those are hideous lol. I'm catless but ended up using a combination of good resonator and muffler to meet local track sound requirements.

yousefnjr · 07-22-2017, 11:18 AM

^^ HA yeah def not pretty, good thing they'll only be on for 20 min at a time lol. I don't track enough to want to change my street setup, which sounds just right to my ear

Quote:

Originally Posted by Finnegan

They look like they're on fire already!

Best solution I've seen is using the 991.1 GT3 exhaust system valves plus Raspberry Pi and GPS to geofence the sound station and go into stealth mode through that spot.

Sans the hardware this looks like a good bet!

Some serious effort going into not having to lift off the gas for a second, love it

best of all worlds!

dc_wright · 07-22-2017, 04:37 PM

I use these when we go to noise limited sites. They knock the sound level down about 8-9dB at 50 feet. They're not pretty, but they're not quite as hideous as those red elbows....

07-20-2017, 02:08 PM	#1
yousefnjr salty cowboys fan 6158 Rep 3,406 Posts Drives: ‘06 Z4MR, ‘20 X7, ‘22 M4x Join Date: Dec 2012 Location: Bay Area, CA iTrader: (2)	Exhaust Turn-Downs for Track? I was at Laguna about a month ago and got flagged for noise. They have a 90db limit, and got me at 98.5 I saw a handful of cars there with exhaust tips pointed to the left (away from the measuring booth) and I want to try something similar. The tips I saw were all metal, and I'd really like to have some in silicone just for easy install/removal. I spent a long time looking online for the highest rated temp silicone I could find and came across these. They're made with Nomex and good for ~500 degrees F. I measured my tips after a drive and the highest reading I could get was in the 240 degree range. I assume the gas coming out at WOT gets hotter than that, but I have no idea how hot. Anybody know? Running full catless. Semi-related to that, fuel is supposedly bad for these, but I figure a few sessions here and there should be ok Ordered 4 of them, they slip right on the stromung 3" tips. They're a little thick though, will take some massaging to get them well fitted. Will update if the Z becomes a massive fireball __________________ she’s home! '22 M4 Comp xDrive
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07-21-2017, 01:47 AM	#2
ZAR4MC Private First Class 93 Rep 133 Posts Drives: '07 Z4 M Coupe Join Date: Jul 2016 Location: RSA iTrader: (0)	PLS, Take a video of the sound with them on all 4... want to see how the exhaust note changes __________________ 07 Z4 ///M Coupe - Sapphire Black / Imola Red My S54 Journal
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07-21-2017, 07:54 PM	#3
Finnegan Dog Listener 701 Rep 7,850 Posts Drives: Z4M/. Z3M, E36/46 M3 Join Date: Oct 2008 Location: Teaching the dog to slalom iTrader: (22)	They look like they're on fire already! Best solution I've seen is using the 991.1 GT3 exhaust system valves plus Raspberry Pi and GPS to geofence the sound station and go into stealth mode through that spot. Sans the hardware this looks like a good bet!
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07-21-2017, 09:22 PM	#4
3002 tii Lieutenant General 2282 Rep 12,565 Posts Drives: Z4 M, X5, GX460 Join Date: Apr 2008 Location: CT iTrader: (99) Garage List F15 X5 xDrive35i [8.75] E86 Z4 M [10.00] F10 550i (Retired) [9.17] F25 X3 xDrive35i (R ... [9.43] E82 135is (Retired) [9.50] E85 Z4 M (Retired) [9.41] E90 328i xDrive (Re ... [9.25] E86 Z4 3.0si (Retired) [9.24]	I know they're functional but man those are hideous lol. I'm catless but ended up using a combination of good resonator and muffler to meet local track sound requirements. __________________ Follow for latest mods
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07-22-2017, 04:37 PM	#6
dc_wright Captain 249 Rep 758 Posts Drives: 2006 Z43.0si Roadster Join Date: Oct 2014 Location: Orlando, FL iTrader: (0)	I use these when we go to noise limited sites. They knock the sound level down about 8-9dB at 50 feet. They're not pretty, but they're not quite as hideous as those red elbows.... Attached Images __________________ Top Down 365
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