I to was wondering about the standard 40 series versus the 40 delta flow. I already put on a 70 series last month & taking it off. Not loud at all, pretty good rumble though. I really want to make sure the next one is loud enough. The part I need is 3 inch offset inlet\outlet & I haven't found it listed for the 40 series only the 40 series delta flow. Is there a noticable sound difference?

 

Definatley orig. 40 series !!!! I have stainless headers, 3 in. pipe and ran it out the side in front of pass. tire w/ gibson supertruck exhaust tips, sounds mean. Oh, no cats on mine in Indiana if you have 10,000lb. plates, there is no emissions testing. Not sure the number though, used one I had in the garage off my chevelle or nova cant rember which one ??? HUM ???

 

robleeg- Are you running true duals?

 

So does anyone have any more input on the 40 series or 40 delta flow? I would rather have it be not too loud and clean than have a loud airy like sound. Anyone know how much louder the 40 series is compared to the delta flow? Also, on either one, how much of a difference will getting the dual output make? I'm hoping for 3in tips if I go that route. Any input is appreciated. Thanks!

 

Where are the inlets/outlets on the mufflers you guys are putting on and how does it fit? We put an Offset/Offset on my Dad's Superduty and the muffler is just a inch or two away from the bed. Just wondering if a Center/Offset fits better...

 

*bump*

My b-day, anniversary & Christmas time are getting near, and I'm begging for a muffler. SO, which is it guys? Is the Delta Flow 40 louder or mellower, than regular 40??

 

The Delta Flow 40 is quieter than the original 40 series. That is what it was designed for.

 

I put a 40 series Flowmaster on my truck when i had single exhaust,and did not like it at all.When i would really get on it it sounded like a big air leak
fffffffffffftt,almost restricted.I removed it after about 3 weeks,i could not stand it.I personally endorse Magnaflow's because it is a straight thru design instead of baffles and what not that the Flow's have.Just my opinion.

 

I can hear my FM 40 in the cab at highway speeds. But I like it . The guy at my muffler shop ("No Muff to Tough" in Bakersfield, Ca.) had done a few V10's and said that the FM 40 was the best sounding he had done. Anyone else think that it is a little on the small side. Can't be more than a foot long. Anyways gonna be getting a Banks power pack beging of 05.

 

I had the Flowmaster 40 on my truck until about ten days ago. The guy at my muffler shop talked me into trying a Full Boar Performance V-Tube muffler. I can honestly say I like it 10 times better than I did the Flowmaster. It is a straight through design, like the Magnaflow, and at idle it has a deep rumble to it. On the top end, it just screams power, but is quiet in the cab. I've had two people tell me it is the best sounding V10 they've heard.

 

What was the part number on the Full Boar? I am thinking about trying one, just do not want it to be any louder than the delta 40. I am running single exhaust now and am going to keep it that way.

 

The part number on my Full Boar is V4164T, but mine is single in, dual out... 3" on the inlet side and 2.5" outlets. Mine is the "V-Tube" design, and it is definitely louder than the Flowmaster Delta 40 series, but it is not loud inside the cab.

 

Finally made my choice, put on a delta flow 40, part number 943043. After hearing another trunk with 3" in and 2.5" dual out I was sold. I really did not want it much louder. I kept my stock single exhaust 3" in, 3" out and the sound is a little less than with duals. I almost think it could be louder, this thing is tame. Has a good low rumble, but I had to put down both windows to even hear it. Highway speed I can't even tell. In my opinion it has a v8 Mustang sound to it at low RPM. I think now that I have heard the single DF 40, I would either go to duals or the regular 40 series. I don't know how the 70 ot 50 series sounds but it must be quietier than stock based on my sound levels with the DF40.

For anyone wanting to do it themselves, I just hacked out the old muffler next to the original welds, cut the bracket off the top of the muffler for re-use on the flowmaster, welded the flowmaster on the inlet side, took a piece of 3" pipe I got at Autozone, cut it down and made up the difference on the back to connect to the tailpipe, you need about 6" to make up the difference. I had a few problems getting the top pieces welded since it was kinda a tight fit, but some Jedi welding got it pretty good. I took the top support bracket from the stock muffler and tacked it to the flowmaster.

 

Had mine done about three weeks ago. Original Flowmaster 40 Single In w/dual 2.25" out. Exiting out the back through 3.5" stainless slash tips that are 18" long. Sounds awesome. Not too loud at all at highway speeds. I have a 5-speed and you can barely hear it at all in 5th on the highway. To me it's just right - loud but with a good tone and definitely not obnoxious. I love the rumble when you wind out second or third and then get off the throttle. No loud popping which I can't stand. I was pulling a 16ft cargo trailer loaded to the gills the other day and passed two guys in another 250 SD. Was pretty much wound out in third gear as I went by them after a stoplight. Pulled over at a coveinence store a few miles down the road and so did they. They asked me about my set up and said it sounded really cool and plenty loud when I went by them. They said they were sitting at the light half asleep when I came by and they just looked at each other and one said "What the hell was that?" I think you definitely want to have it exit out the back if you're worrying about cab noise. I think it looks better too. Last week I pulled a 12ft steel cargo trailer loaded to the ceiling with a weeks worth of gear for 22 Boy Scouts and 9 adults from Dallas to Mena, AR. Truck performed woderfully. No loss in power or torque. In fact, the truck seemed to be able to hold fifth gear on long grades better than it did before the exhaust. Ran 80mph in fifth on I-30 all the way from Dallas to damn near Texarkana - no problem Still puts a smile on my face every time I start it, but my gas mileage has gone all to hell because my foot is in it all the time now.

 

I had a 40 delta flow put on today, and all I can say is WOW! It is has the low rumble and is not really noticable until you jump on it. The muffler shop charged $110 installed. The 40 would have been too much I was told by the installer. It is a little louder on the exterior and barely noticable inside than the stock. Filled up the tank and did my normal drive and notice that I was getting 1-2 mpg better. This could be the combo of the K&N and the FlowMaster, but either way I'm impressed.