I have a 12a with a big street port, I'm running a baby Flowmaster 10 series muffler. I just put in a intercom system and the motor is tripping the voice activation on the intercom system. What would be a good performance muffler that quits the motor down

 

Put your Flowmaster on the end of a Borla stainless of the same diameter. We gave up on the radios



for the same reason. We had to put the exhaust out the right side to make the noise regulation (103Db)

And that made it real loud. Setting of the mike.



Lynn E. Hanover

 

The moroso spiral flow will cut a few Db's plus it will never burn out!

ANY strait through canister will be loud as hell and it seems that they burn out pretty fast under the rotarys heat..

The cheapo turbo style mufflers will cut out some noise but the exhaust note sucks..



Right now I'm running a Supertrapp tunable muffler the soft tech padding is high heat resistance.. and you can cut out as much noise as you want to, just by adding or removing diffuser discs... (IMO) It makes a great exhaust note...

 

I forgot about my supertrap, I have it installed at the end of the exhust system. I'm not running the diffuser discs, someone told me they create back pressure! I thought rotarys don't like back pressure.

 

True.. rotary's Hate backpressure and and the diffuser discs do cause backpressure... untill you have like 20 discs in it..

Supertrapp says around 20 to 24 discs is considered a open pipe!! Witch will muffle your exhaust without adding extra back pressure..



Rotarys will run fine under backpressure( i.e. the stock exhaust system). The reason they have the rap of hating backpressure is because the amount of power you get from them after replacing the stock system....



I know mine runs better with all the discs out but damn is it LOUD!!!

 

Thank for the good explanation! I will try it..

 

I have my bridgeport quietened down quite well with 2 presilencers and a magnaflow. I am adding a qtec http://www.quicktimeperformance.com/QTEC/index.php so I can have race readiness while still having good streetability.