Were the original style e-body mufflers (2-1/4" in, mounted beside the tank) a straight through type of design?

I have a pair on my Challenger but they are welded in place (no resonators).

I am curious how much of a performance gain there would be in swapping these 2-1/4"-2" muffler/R/T exhaust tip assemblies out for an aftermarket 2-1/2" straight thru muffler with 2-1/2" R/T tips since I now have headers and 2-1/2" pipe up front before the start of the 2-1/4" tail pipe assembly.

Any thoughts?

Thanks

I'd want 2&1/2 all the way thru (& no mandrel bends). the tech guys say as the mixture cools as it traveling rearward you can get by with a smaller tailpipe but just me I ain't convinced. An easy confirmation would be to uncork it & see what the butt dyno says. After 35 views you ain't getting any love on this Q so here's a BTT for ya

Thank you for the replies.
Do the FAST cars have to run stock tail pipes and tips or can they upgrade to 2.5" after market parts?

Thanks Sunroof for posting that muffler info. I assumed that they may have been a straight thru flow since they are round. I do love the sound of them (no resonators, just these OE type mufflers) but if they are that restrictive, then I will go ahead with my planning to up-size the tail pipe assemblies.

I have been looking at the Magnaflow round body SS versions too. I can buy a set of 2.5 tail pipes and 2.5" R/T exhaust tips from one vendor, then splice in the 2.5" inlet/outlet 6" diameter round bodied mufflers into the same space as the original OE that I currently have. I was just hoping that this would have more flow for the effort.

Thanks again,

As a reference, I found these DB ratings on some of the popular mufflers.

-1.Borla XS, 80db at idle, 90db at 2,000 rpm, 110db at WOT.
-2.Hooker Maxflow, 80db at idle, 90db at 2,000 rpm, 120db at WOT.
-3.Magnaflow, 82db at idle, 91 at 2,000 rpm, 114db at WOT.
-4.Flowmaster, 82db at idle, 93 at 2,000 rpm, 115db at WOT.
-5.Flowtech Warlock, 83db at idle, 92 at 2,000 rpm, 112db at WOT.
-6.Dynomax UltraFlo, 83db at idle, 94 at 2,000 rpm, 113db at WOT.
-7.Borla XR1, 83db at idle, 96db at 2,000 rpm, 118db at WOT.
-8.Bassani Street, 83db at idle, 96db at 2,000 rpm, 120db at WOT.
-9.Edelbrock RPM, 84db at idle, 93db at 2,000 rpm, 118db at WOT.
-10.Bassani Real Street, 84db at idle, 96db at 2,000 rpm, MAX. (120+db).
-11.Flowtech Afterburner, 86db at idle, 94db at 2,000 rpm, 115db at WOT.
-12.Flowtech Terminator, 86db at idle, 94db at 2,000 rpm, 119db at WOT.
-13.Hooker Aerochamber, 87db at idle, 94db at 2,000 rpm, 114db at WOT.
-14.SpinTech, 87db at idle, 97db at 2,000 rpm, 116db at WOT.
-15.MAC, 87db at idle, 98db at 2,000 rpm, 119db at WOT.
-16.No Muffler, 91db at idle, 103db at 2,000 rpm, MAX. (120+db).

"" I would bet that the OE Cuda mufflers had a flow rate of around 175 sCFM for comparison.""

I emailed Magnaflow for the flow rate on the attached style of muffler (#12646 [6" diameter x 18" 2.5" round body], #12616 2.5" round [6" diameter x 14" body] and Magnaflow rates them at 530CFM tested at 28" of water.

I am planning on using these beside the tank with 2.5" tail pipes and 2.5" R/T exhaust tips.

Thanks for the replies.

http://www.accurateltd.com/E-Body-Magnum-Kit_p_371.html

I checked out their Magnum series and this was their reply:

""Our E-body Magnum kit comes only in the 2-1/4" size for various reasons. The required compound bends in the over axle pipes to clear the shock absorbers cannot be done properly with 2-1/2" tubing. These bends are critical to locate the mufflers in the correct locations for a proper fit and so that the exhaust tips exit properly.. The Magnum mufflers and resonators are a full bore design and performance gains would be negligible if any increasing to 2-1/2" internals. We are now at the limit with sound control because of the muffler straight through design and the larger resonator internal size. However the resonators can be expanded at the front to slide over 2.50" head pipes. The Magnum muffler outlets can be expanded for larger exhaust tips as well.""

Thanks for posting.

I had an interesting conversation with Accurate yesterday. My idea of using the above Magnaflows will not work if I use the Accurate 2-1/2" tail pipes. The MF mufflers have their inlet/outlet on center and the tail pipes are designed to fit the original mufflers that have an offset on the inlet side of the muffler.

I found out that the OE 3 chamber muffler flows around the 170cfm range and their 2 chamber Hemi muffler flows around 200cfm. This Hemi muffler would be a direct bolt in and would flow a little better than the OE style that I have on the car currently and it is not real loud for a streeter.

I was also told that the Magnum round muffler flows the same as a 2-1/4" pipe, since it is a straight thru design. It is a loud muffler but if it is used with a resonator, then that brings down the sound just a bit and it is more tolerable on the streeter. I was told that some of the FAST guys use this setup.

Has anyone used this Magnum muffler without a resonator? If so, how loud is it?

Thanks

are you racing this car?

No, just a street car. I am planning some engine modifications next Fall, so I am just trying to plan ahead.

Thanks

not to be a smart ass,but if you take the exact same cars and the only differance is mufflers (400 h.p.) cars,is there and advantage?will one be faster? any good flowing mufflers will be adaquate(sp)for street gigs

My problem is that I am running the OE 3 chamber mufflers that I hear are only 170cfm.

I am just checking out my options.

just dont over think it.