I just got done building my 460 and have to say that the 40 series flowmasters I put on do not sound like what I thought they would. True dual exhaust and turndowns. Anyone else ever feel this way? I hear fox body mustangs with 302s sound better.

 

I have always used Flowmaster 40 series for my Mustangs and liked the sound, I'm getting ready to have the exhaust done on my 79 F-100, 460 and was gonna use a 40 or 44 series muffler but hearing different stories of how they sound on old Ford trucks has got me thinking about my decision, what did you not like about them

 

It sounds pretty good at idle, but anything above that doesn't sound good at all. I was expecting something that sounded mean, maybe not exactly like a mustang, but a mean deep rumble. It sounds very hushed and muffled, not like that "classic 40 series" sound that you know. I just don't get it. Thinking about putting some glasspacks on it, not sure.

 

I assume this is on a pickup, so one way to make them louder (if that is what you are looking for) is to get rid of the tail pipes and turn them out in front of the rear wheels. Shorter pipe, closer to the cab, louder.

My son and I both got Dynomax Super Turbo mufflers on our pickups, both are 4-bangers, and his has the tailpipe and is about half as loud as mine with the exit in front of the rear tire.

 

Paul, yes its a 79 f-250. It already has what you are talking about. I call them dumps or turndowns. They dump right next to the rear tire.

 

It should be extremely loud with Flowmaster 40s. A shop put one on my 2001 Ranger 4-banger and I had to switch it out it was way too loud, that with a side exit, single exhaust. What size piping do you have?

 

I have L&L headers and 2" pipe

 

possibly a larger tip, maybe 2.5 or bigger. I read that larger tips will increase sound. You also said it is turndowns. Is that they point to the ground? I would have it pointing straight out the side, maybe louder??? If you have them exit under the cab or bed it will resonate like crazy.

 

2" dual exhaust?? Should have went with 2 1/2". If a shop used a ram to bend the system then it is way tiny thru the bends. That is probably why it is quiet. Gonna guess you're down on power too.

 

I had a set of 40series copies on my F100 a while back. Stock 390 with headers to dual 2.5" pipes. It had a nice rumble to it and definitely wasn't quiet, but still tolerable. Part of your problem is such a small tailpipe, and the exit location.

For a suggestion, I run super 10s now, and I'll just leave it at this-They are deep and loud.

 

If he is having any power loss due to the 2" pipe size it should only show up at higher RPMs. Should be plenty of flow at lower RPMS. As long as it feels good powerwise, he is all set. As for loudness, as has been said, he can try fatter outlet tips, 2.5", maybe 3". May help. Try it first before cutting the existing by temp mounting them on the ends ,yeah they'll stick out but it's only for a quick run.

 

For greater volume how about switching the FMs out for cherry bombs?

I just sold my used Flowmaster 40 series for $60 on craigs list.

 

I agree with the larger pipes. The single glass pack I have is often times louder at WOT than dual 40's.

Another guy on here went with dual Moroso Spiral flow's on a 390 with headers. Sounds really nice. When I get my system re-worked I'll buy some of those. I'll try to find the video.


Jameson

 

Just got done putting on BANKS headers, y pipe and there muffler. Resulting in quieter then stock. Thinking it must be the massive factory cat

 

I went through the same thing with my 92 f350 with the 460. I had a flowmaster 40 with 3" tail pipes. It was soo quiet. I was very disappointed. I deleted the factory cat, and wow what a difference. when it came time for emissions I used a high flow cat from magna flow and clamped it in.