[66 Chevelle Bob]

Thanks guys for the response to my Drone problem in my 66 396
Auto convertible. My Flowmaster 70 Series Big Block II-Three Chamber Mufflers which Flowmaster says are there most quiet are a crock. Even with my H pipe and 2 1/2 inch exhaust I can't hear the darn radio while stepping on the gas up a hill. No headers either. The majority are recommending Walker Dyno Max Hemi Turbos so here goes another quick $200 out the door and I eat my third pair of Flowies. Before I dive off the board again-ANY SUGGESTIONS ON ANY OTHER MUFFLERS that I won't need ADVIL with?

Thanks alot-Us Chevelle guys have to stick together as the big parts companys try to sell us everything...

Bob in CT

 

[69-CHVL]

Whats interesting is that I had the 50 deltas in the 2.5" version behind my 396. They were quite, very little to no drone/resonance at all. Can't see how the 70's are louder. You may wanna look into other things.

 

[74malibu]

I agree. I had 2.5" original 40's w/ H-pipe behind a small block and could hear my radio just fine. It was a completely different story when I removed the tailpipes though.

 

[73guna]

Ive heard that the Dynomax super turbos are quiet.

 

[GRN69CHV]

I have the 20" case Hemi Turbos (2.5" in/out). Worked very well behind the 9.5/1 400HP 402 motor. Behind the 10.3/1 550HP 460CI motor, they are still rather quiet but are choking the motor. I am going to 3" Ultraflows, which my guess is may become loud. Behind a 396 motor, the turbos are a good choice for a quiet muffler.

 

[SS4Real]

Your timing is perfect as I just installed new mufflers on my system. If you want extremely quiet mufflers on the inside with a very slight rumble on the outside, go with Dynomax 17749's Turbo's (often called the semi hemi turbos) which are the 20" case and still flow very well. I had them on my stock '70 SS454 for the last 2 years. I wanted a little bit more rumble on the outside but still quiet on the inside with no resonance or drone so I just upgraded to Dynomax 17734's with are the turbo mufflers and are 14" in length. They are still quiet on the inside with no resonance with a more throaty rumble on the outside and when you jump on it. But still great for cruising and very quiet on the inside. I'm running a 2 1/2" full system with full tailpipes through stock exhaust manifolds with an H pipe.

 

[Nicks406]

the Dynomax's are only around 50 each and they dont drone on the cars i have put them on. what sor tof tailpipe exit do you have? turned down? straight out? past bumper, before bumper?

Flowmasters are junk. Don't believe the hype.