: making the car quieter - "selectively"



jclayc
03-04-12, 06:05 PM
Anyone with any ideas on how to bolt something on to easily make the car quieter by like 10db from the outside @ like 30 yds? Even something hack (non-destructive).

4" band clamps, some steel wool and chicken wire at the tips?

darkman
03-04-12, 06:42 PM
What exhaust do you currently have? Stock tips? If not, what size?

jclayc
03-04-12, 07:19 PM
ah, good questions - stock headers, magnaflow catback w/ 4" tips, I believe

darkman
03-04-12, 07:26 PM
One way to do is to remove the existing tips and replace them with short, chrome motorcylcle mufflers. They some with 2.5 inch inlets and 4 inch outlets. If you made the existing tips "removeable" with some claps you could even switch back and forth.

AAIIIC
03-04-12, 09:20 PM
Anyone with any ideas on how to bolt something on to easily make the car quieter by like 10db from the outside @ like 30 yds? Even something hack (non-destructive).
Is this for a state inspection? Or maybe a sound limit at a road course? 10dB is a LOT of reduction.


4" band clamps, some steel wool and chicken wire at the tips?
I've heard of folks doing that. You need to make sure there's something to keep the steel wool from going forward (into the muffler).

Some other possibilities... I've never used any of these, so I don't know how effective they are.

- Here are some 4" inserts (http://www.summitracing.com/parts/DTC-772-32530/) for noise reduction. I'm not sure whether the Magnaflow tips are even long enough to fit 7.5" long inserts, though.

- Harder to remove would be something like this (http://www.summitracing.com/parts/CCI-3DI25R/) put into the straight leg of pipe that runs alongside the diff. Obviously you'd have to remove the muffler sections in order to install the inserts from the upstream side. Actually, now that I look at my pictures of the underside of the car, it looks like the only accessible straight shot of pipe would be just downstream of the X in the Magnaflow system. So those probably aren't a practical suggestion.

- Or the same thing, but 4" diameter (http://www.summitracing.com/parts/CCI-3DI04L/) to fit into the exhaust tip. Again, length might be an issue.

- If this is for sound restrictions at a track day, I've seen this method used successfully. Some might want to install turn-down tips, but apparently the sound just reflects off the road surface and doesn't gain you much attenuation. Turning the tip so it points up (and away from wherever the monitoring station is) allows the sound to dissipate into the air.

DDS rollin a CTS
03-04-12, 09:39 PM
I dont get it, why would you want to make your car...quieter???

jclayc
03-05-12, 08:26 AM
the cones look like a good idea... I'd rather not pull the mufflers so perhaps I'll try those first. I wish I could rig up something like a supertrapp but that's unlikely w/o significant modifications

re: the picture of the subaru - yeah, I've seen some with a full, extra muffler strapped on kind of like that. I think I'd go with a chicken wire and steel wool sandwich before that