ratio411
Founding Member
They use an H-pipe too though. I think that plays into it.mustangdave said:
Also, is it Mustang that is now using an H-pipe behind the mufflers? I think so, not sure.
Dave
How do i lessen the Flowmaster drone?
- Thread starter 65shlbycln
- Start date
Also, is it Mustang that is now using an H-pipe behind the mufflers? I think so, not sure.
Dave
Hack
15 Year Member
If you read above, the explanation is very good. At a certain rpm, the tailpipes act like a pipe on an organ, amplifying the exhaust sound. This makes the car louder. If the car is already loud, and the rpm where the sound is amplified is your cruising rpm, it can be very annoying.cobra1 said:
The suggestion above to offset the mufflers so that the pipes are different lengths is a very good one. That would reduce the amplification. Edit: it also has the advantage of simplicity, even though it wouldn't be as effective as the additional pipe.
I remember I used to have a '76 Cutlass with glass packs back when I graduated high school. I had a 5 hour drive from home to college, and my ears would ring for hours after. Course it didn't help that I also had to crank the stereo.
Pakrat
Founding Member
So what is the answer BTW to the "glass packs in front of the flows" question anyway? Does anyone know? I figured eventually I'd replace my packs with something, but it never occured to me to just move them up and run both. Is there any advantage to that as in the picture?
ratio411 said:
Ford Racing has an exhaust that has an X-pipe after the mufflers. It's for the late model Cobras with the IRS. The X sits right under the third member, or thereabouts.
It's a combination of the H-pipe, the offset, and that the mufflers are differen't sizes that help cancel out the drone on the Mustangs.
Yes, late models use an H pipe but it will work on regular dual exhaust. I did this on mine. I bought some flexible clamp on pipe and cut one pipe about three inches shorter and test drove. I played around with the lengths until I eliminated the drone, then took it to a muffler shop and had the system welded with real pipe.I could tell you the measurements I wound up with but it is different depending on your engine, mufflers, headers, pipe size and bends so you have to experiment a little. No matter what you shorten or lengthen one pipe to, you should notice an immediate difference. I have a stock 302 with headers, dual exhaust and galsspacks, so this problem is not specific to any brand of muffler such as Flowmasters; heck, even Ford had this problem with the stock mufflers.
MrBobMarley
Founding Member
dodgestang
Active Member
Pakrat said:
The advantage is lower DB without sacraficing flow.
Opentracker runs glass packs that have the same inner diamter as his pipes....so if he has 2.5 inch pipes, the glasss packs would have 2.5 inner diamter. With them mounted inline they don't restrict any flow, but serve to decrease over all exhaust noise.
MrBobMarley
Founding Member
Pakrat
Founding Member
Hmm interesting, so sounds like using them in front of flows would bring the sound down. Hunh, that seems so weird since I have to believe that the packs are even louder than flows when running either or. At least I know my packs are pretty loud under heavy acceleration. 
I bought a used Magnaflow catback for my '02 GT and the seller included a pair of Bassani resonators/baffles. They fit right into the exhaust tips and are held in place by a set screw. When I put them in it cuts down the sound a LOT...almost down to stock. I'm not sure what hte diameter of the baffles are, but if you're interested I can go home and measure them. I'm not sure if this would help your situation much, but it might be a good solution if paired with an H-pipe, etc.
steelhorse
Member
I have long tube headers, 2.5 pipe 40 series flo's, no crossover and the pipes dump just before the rear end. No drone. I used to have 2" pipe and form motorsport mufflers that were side exit just before the back wheels and the drone was much much worse.
