rayfry

I installed a series 40 flowmaster muffler and cat back dual exhaust on my 2004 silverado 5.3. The muffler has 1 inlet and then 2 outlets. The drone in the cab at lower rpm's is deafening. The truck sounds great outside but in the cab the drone is unbearable. Any suggestions without replacing the whole exhaust system?

JK23112

I have had Flowmasters (true duals from the cats on back) on my truck since last spring, but mine are the "50" Series. I thought the 40 ones were too loud and the 70 Series was too quiet.

Short of going to a 50 Series, I guess you should either live with it or install a louder stereo system in your truck.

rayfry

thanks for the reply..what about installing a heat shield on the muffler to direct the sound down and away from the cab

JK23112

Don't know about that.....but perhaps someone at a muffler shop might be of some assistance.

rayfry

ok thanks..I know summit sells a heat shield for flowmasters.

ToooTall1

Does your exhaust extend out the back to the bumper or just a short pipe turning down at the muffler. The noise is just defening at the muffler in the cab w/o pipes but with pipes out the rear their Great sounding. Have the same muffler but going out back and sounds great at idle and under power, plus gained 3mpg from stock exhaust. Not true duals but good for me.

rayfry

No my pipes go out to the rear bumper but the rumble in the cab is bad.

s34n

talk to your local muffler shop about having them install a resonator. i had one installed on my 04 1500 with the 40 series there was definitely a noise difference between having the resonator and not having one. if you want to quiet the noise down, short of installing a new muffler out, check this alternative out. good luck

rayfry

thanks for that tip, i'll speak to my installer