89IROCZZ4

I am thinking about going for a sleeper effect, in the way of having a stock muffler to severely quiet down the sound of the car, until i flip a switch that would open up a cut out. How would a 383 with great flowing heads, a big cam and long tube headers sound through a stock muffler? Is there anything else to make it quiet? I would love to not scare anyone away if I start it up.....until we line em up

70formula

I'm with you. I prefer a sleeper. I'm wondering what the quietest mufflers would be. I'm also going with a 383 and no cat.

Mark A Shields

I'd still go with an aftermarket quiet muffler. I hear some of the dynomax ones are quiet. Not sure which part #s though

89IROCZZ4

will people still be able to listen and hear that we are modified though?

kfoley

Well a healthy 383 with longtubes and a stock muffler would still be pretty loud (not to mention you would lose a LOT of power due to the restriction). For example we did a performance rebuild on my truck this spring and before you could hardly hear it through the stock muffler, now it's almost as loud as the dual setup I have on my stock LG4 (and that's with aerochamber center in/out mufflers). If you're looking for quiet without sacrificing lots of power I would look at dynomax. They have great flowing products that muffle very well. Most sleepers use their mufflers.

AFatHippo

a cat would make it quieter. here is an idea...isnt too practical but ill say it anyway. ok, you have your longtube headers, then a y-pipe with the best diameter for performance. then, youll have your cutout. so anything past the cutout could be sacrificed performance-wise if youre going to be racing with the cutout open. so, you could get say a 2.5" cat and run a 2.25" pipe the rest of the way to the stock muffler. the smaller pipe should make it even quieter.

if you dont go as all-out, good aftermarket mufflers for sleepers would be a dynomax or flowmaster 70 series. by the way sleepers rule! i have a flowmaster force II catback on my car (quiet and single tailpipe) and completely stock exterior besides iroc wheels. surprises people every time

kfoley

I wouldn't use 2.25" pipe. I chokes a 305, let alone a well built 383. Just use 2.5" duals with good Dynomax turbo mufflers. Oh, and h-pipes (and x-pipes) are supposed to quiet it down too.

88IROC350TPI

Dynomax Ultra Flow's and "Super Turbo Hemi" mufflers are VERY quiet yet flow just as good as any other aftermarket muffler. Keep in mind they're very big too.

70formula

I spoke to someone at Dynomax the other day and got some great info. He suggested I go with an Ultra Flow with a Dynomax "bullet" type of muffler right before it somewhere on the midpipe. He said there wouldn't be any restrictions because of the straight thru design of the "bullet" which still has some sound muffling qualities. So it looks like I'm going with 2 mufflers to quiet my 383 down.