Getting rid of muffler drone- easy DIY

[tshebib]

Last winters project of installing a 3.6vram in my SC was a complete success. I love the new found power and I think I have the best sounding car at our local DE events (I may be a little biased). Problem is the magnaflow 2in 2 out is downright nasty at highway cruising speeds. I also ran into a little trouble at Calabogie Motorsport Park with their noise restrictions. That was a little stressful after driving over 15 hours to get there! They eventually let me run though.
After lots of researching this forum and too much time on my hands this winter I came up with a fairly simple solution. Those American ride height spacers on the top of our front struts are the perfect diameter to fit inside the tailpipe. Just remove at the track (when there are no noise restrictions) and go have fun!!

[rnln]

can you say proximately how much noise are you reducing, %?

[kodioneill]

How about some photos of the engine installation and your car.

[tshebib]

I would guess the noise level is down approx. 20-30%?. If it weren't for the salt and snow still on the ground here I would do a db reading with my iphone. I know at Calabogie they said I was well over 105 db at 15 feet away and half throttle.

[tshebib]

Originally Posted by kodioneill

How about some photos of the engine installation and your car.

Here's a link to my install last year.
Finally registered with Pelican- Introduction

I also had to do a brake upgrade as part of this winter's to do list....the slippery slope never ends

[dw1]

Congrats on a simple solution to a nagging problem. I'm glad it worked out well for your car.

I did something similar with my 84mm Dansk 1-in-2-out on my '87 3.2, but the measured sound level reduction (7-9 dB at low rpm) wasn't as much as I had hoped.

And yes, I do have my own calibrated sound level meters.

I am currently experimenting with homemade baffles in the style of the old muscle car exhaust resonators and currently popular motorcycle exhaust baffles. (Sort of like the euro premuffler, but post-muffler). I'll certainly let the community know how that works out.

[rnln]

I have been thinking about this for a long time but still have not done it, because I am not sure how much vibration (sound) I eliminate.
I love my current sounding, not too lound at all, but everytime getting into the parking structure, I set off several cars alarms. I know that those cars alarms are too sensitive, but I hate people notice when I come. Also, I have a euro pre-muffler sit in the corner of my garage. If I put that in, I afraid I will set off 20 cars at the same times.
20%-30% is good enough to give it a try. Thanks.

[tshebib]

Originally Posted by rnln

I have been thinking about this for a long time but still have not done it, because I am not sure how much vibration (sound) I eliminate.
I love my current sounding, not too lound at all, but everytime getting into the parking structure, I set off several cars alarms. I know that those cars alarms are too sensitive, but I hate people notice when I come. Also, I have a euro pre-muffler sit in the corner of my garage. If I put that in, I afraid I will set off 20 cars at the same times.
20%-30% is good enough to give it a try. Thanks.

The biggest complaint I had was the "drone" while cruising on the highway.
As far as reduction in the actual sound level goes, I'll get some real numbers for you within the next few days. You mentioned pre-muffler. Are you running a 1-in 2-out? What brand of muffler is it?

[Jaskas]

I solved my similar droning issue with a electric cutout valve. Works great!

[rnln]

1 in 2 out, each side at the output has dual tips. So you can say 1 in 2 out but 4 tips. This is the borla turbo muffler but modified to fit in the non-turbo 911. Sound great, not lound at all. I don't complain about sound, in fact I love it. The only thing I don't like is that it set off some alarms when going into a tight parking structure.
The premuffler that I mentioned was the device structure similar to the charrybomb (in the inside) and will replace the cat. This thing will definitely give it more sonic sound

Jaskas, can you post some pics?

[dw1]

Originally Posted by Jaskas

I solved my similar droning issue with a electric cutout valve. Works great!

PLEASE post pics of how & where you mounted this. And other applicable info would be GREATLY appreciated - like what size valve you used, what type of actuator, who you bought it from, etc.

I've playing with this approach for awhile and can't get something that is a good size for the pipes, and can't find a good place to mount the exhaust valve flanges and actuator.

Thanks.