I got the Jones Full Boar 2590 installed. It is 5x11x22" with 3" in and two 3" out.
It is just barely louder than the stock (likely worn out) 7.5x12x24" muffler that is 2.75 in and two 3" out. The biggest loudness difference (after only about 25 miles with it) seems to be at idle. There is absolutely no hint of any drone. It does accelerate more smartly, but initial gas mileage seems to be about 1 mpg less with the new muffler. I will give the computer more time to get used to the muffler before jumping to any conclusions. I really like it. No off idle loss of torque was perceived. This is likely due to the restrictive leftover 5.3 y-pipe.
The muffler shop cut the old OEM muffler out and only had to add a reducing collar to the front. No extra pipe or hangers needed. I expected that the new free flowing muffler would be significantly louder than it is. The 2590 does not get much louder as rpms increase. That is a surprise. I punched it while cruising at 70 on the freeway and was at 105 in less than a quarter mile...more like 3 blocks.
Now for the stock muffler. It turns out that the outlet closest to the driveshaft does appear to be at least somewhat blocked by a plate or baffle. It is certainly different than the other side. It may be more of an inlet than an outlet. The short Y behind the muffler may direct some gases back into the baffled side to be mixed with the other side (closest to the passenger side) before exiting.
At any rate, the MF2590 now flows out to both sides of the rear y. Total cost was $63 shipped for the muffler and $65 with tax for the install...or $128 out the door. Did I mention that there is not even the slightest hint of drone? I almost wish it were a touch more aggressive sounding.
At the suggestion of Jones, I found a youtube video showing the comparable Full Boar and Magnaflow mufflers on a flow bench. The Magnaflow flowed about 474 cfm and the comparable Jones was almost 100 cfm higher at 566 cfm.
https://www.youtube.com/watch?v=wxPIt-eoT3w
It is just barely louder than the stock (likely worn out) 7.5x12x24" muffler that is 2.75 in and two 3" out. The biggest loudness difference (after only about 25 miles with it) seems to be at idle. There is absolutely no hint of any drone. It does accelerate more smartly, but initial gas mileage seems to be about 1 mpg less with the new muffler. I will give the computer more time to get used to the muffler before jumping to any conclusions. I really like it. No off idle loss of torque was perceived. This is likely due to the restrictive leftover 5.3 y-pipe.
The muffler shop cut the old OEM muffler out and only had to add a reducing collar to the front. No extra pipe or hangers needed. I expected that the new free flowing muffler would be significantly louder than it is. The 2590 does not get much louder as rpms increase. That is a surprise. I punched it while cruising at 70 on the freeway and was at 105 in less than a quarter mile...more like 3 blocks.
Now for the stock muffler. It turns out that the outlet closest to the driveshaft does appear to be at least somewhat blocked by a plate or baffle. It is certainly different than the other side. It may be more of an inlet than an outlet. The short Y behind the muffler may direct some gases back into the baffled side to be mixed with the other side (closest to the passenger side) before exiting.
At any rate, the MF2590 now flows out to both sides of the rear y. Total cost was $63 shipped for the muffler and $65 with tax for the install...or $128 out the door. Did I mention that there is not even the slightest hint of drone? I almost wish it were a touch more aggressive sounding.
At the suggestion of Jones, I found a youtube video showing the comparable Full Boar and Magnaflow mufflers on a flow bench. The Magnaflow flowed about 474 cfm and the comparable Jones was almost 100 cfm higher at 566 cfm.
https://www.youtube.com/watch?v=wxPIt-eoT3w
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