Mufflerectomy: Dynomax, Magnaflow, other?

[woundedbear]

Sorry if some here think that this subject has been beat to death, but searching through all of the posts on this topic, I could not find the answer I was looking for.

I, like some have done here, am looking to remove the OE muffler from the OE 3.5" exhaust and splice in a straight-through free flow muffler. I realize that the more free the exhaust flow, the louder the exhaust will become, but I want to minimize my decibel increase as much as possible.

From another topic, JK stated that from his experience, perforated cored mufflers are slightly louder that louvered cored mufflers.

Someone also stated that Allied manufactures louvered cored mufflers, but I cannot find a dealer who can confirm this or even sell them.

Right now, I am looking at a Dynomax Ultra-Flo and a Magnaflow. The Dynomax, according to the not so adept tech guy, has a perforated core. The Magnaflow website states no chambers, louvers or baffels. :confused: What do they have? Which one is quieter?

Can anyone offer any insight on these or any other straight-through mufflers, as well as a subjective opinion on noise levels?

JK, do you sell just the muffler from your 4" system?

[LarryM]

woundedbear,

Can't help much with Magnaflow or Dynamax. When I decided to look at a mufflerectomy, a local shop wanted about 350 bux to insert a Magnaflow. Later I found a shop that would put in Walker straight through muffler for only 100 bux. The Walker is 4 inch in and out, about 8 inches in diameter and 27 inches long. You could drop a 3 7/8 inch diameter ball straight through the thing! It is pretty quiet on the OEM 3.5 inch pipes. There is a little resonance at about 1600 RPM at light throttle, other wise little difference from stock. My wife never heard the difference at all.

[CanadaKev]

woundedbear,
I am running the 4" Magnaflow. Dim.14"L x 7" dia.
It is a perforated muffler. It's a little louder than stock, but not much. No resonance.

Kev

[Dave S]

I just had the largest Dynomax(Walker) p/n 22572 installed in the stock 3.5" pipe. It measures 4"in/out, 20"x9" body(27" overall) Interior wise there is some resonance ~1600-1700rpm, a slight rumble near the shift points and stock sound levels while cruising above 1700 rpm's. This observation is while unloaded and I am sure it will get louder when a load is applied. Outside you can definetely hear the whistling sound of air rushing out the tailpipe(like a semi)at idle/low rpm's and turns to a slight rumble at WOT as rpm's and boost increase. At normal highway speeds you don't know it's there. The biggest problem, as JK has mentioned in other posts, is the offset between the front and rear of the muffler. This requires the muffler to be mounted on an angle with the rear angled upward. Not pretty! Does anyone have experience with the Magnaflow p/n12773? The body measures 30", 36" overall with 4" in/out.

[Idle_Chatter]

I've got a Magnaflow spliced in in place of the factory muffler. It's a 4" straight-through with a perforated core. Not really as loud as I expected. A bit of resonance at 1500 rpm, but not really annoying and drops right off either side of 1500. I've been pretty happy with it.

[Maverick]

For those of you that staight piped your Dmax, how would you compare noise level to say a KD or Banks exhaust? Is it so loud that its just to loud?

[mtomac]

First I ditched the stock muffler and went with a straight pipe. It was bearable empty if you didn't have your foot in the floor but towing it was just way too LOUD but it dropped exhaust temps. Then I went with the flowmaster muffler part #953553 on the stock exhaust. Not much louder than stock, exhaust temps stayed down and I think it sounds better than the banks dynaflow muffler.

[ 12-14-2003, 05:19 PM: Message edited by: Micheal Tomac ]

[Dave S]

Micheal
What are the dimensions of Flowmaster p/n 953558? Offset or centered in/outs? I couldn't find a description on their website. Do you notice any resonance inside while driving? If so under what conditions. Could you detect a difference in performance between stock, straight piped, or the Flowmaster?

[mtomac]

The flowmaster is a bolt in application with center inlet and offset outlet. Make sure when you cut the stock muffler off you cut as close as possible to the muffler. The biggest downfall is the flowmaster isn't available in stainless.

The flowmaster is a good balance between the stock muffler and a straight pipe. It's still quiet at an idle and driving around empty unless you get on it then it's louder outside without as much noise as the straight pipe one the inside.

Towing I pick up a little resonance inside around 55mph if I'm in 5th. In 4th it isn't there and empty I don't hear any resonance in the cab utill 85mph and up. EGT's were 50-100 degrees lower with the straight pipe and are about the same with the flowmaster. I've never saw over 1300 degrees with the flowmaster or straight pipe. With the stock muffler I could get it there when towing.

[ 04-03-2003: Message edited by: Micheal Tomac ]</p>

[woundedbear]

Thanks for the replies, guys.

I have decided to go with the Magnaflow 20" body, 7" diameter, stainless muffler (P/N 14771) with the 4"-&gt;3.5" stainless reducers (P/N 15441) at ~$145 + shipping.

I am a little concerned about resonance. Since there is no resonance on the OE exhaust, it should be a matter of matching the mass of the Magnaflow muffler to the mass of the OE beast. One way to accomplish this would be to "weld" lead onto the Magnaflow muffler. After I complete the mufflerectomy, I will see if the extra effort is necessary.

[Allison Jettester]

Woundedbear,
Where did you get your muffler and reducers. Let us know after you install it what you think.

Thanks,
Joe

[woundedbear]

AJ,

In one of the threads related to mufflerectomies, www.henschelandsons.com was mentioned. After checking with several local and national retailers, no one could even come close to matching their prices.

It might be a little while until I complete the job. With number two on the way, my "honey do" list has increased significantly.

[Idle_Chatter]

I thought that your choice was familiar, Woundedbear, that's the muffler and reducers that I have on my truck. I cut the factory muffler out as close to the muffler as possible with a chain-type cutter. That left a "stub" of pipe inside the two hangers. The 4" neck of the muffler had to be trimmed back and the 3-1/2" portion of the reducers to fit back in the space vacated by the factory muffler on my shortbox extended cab truck. I band-clamped the reducers into the muffler, wedged it all back together and tack welded the reducers to the pipes. Then I released the band clamps and took it out in three pieces for final welding and reassembled it with the band clamps. I like having an easily removable system more than I worry about the clamped joints, but I suppose you could weld one of the muffler/reducer joints and go with only one clamp if you wanted.

[woundedbear]

Idle_Chatter,

Thanks for sharing your experience with the mufflerectomy. Where are the pics? I would be interested in seeing how your install looks.

My initial thoughts were to use the 24" body, but because of the offset and the reducers, realized that the 20" would fit a little easier.

Hard to believe that cost of the two reducers equals half the cost of the muffler... :confused:

[Maverick]

Micheal Tomac,

I found the Flowmaster muffler locally for $175. I was wondering how this compared to lower 48 pricing? How much were the 3.5" band clamps? The dealer said it had an offset in and out. You said it was a center in? What is the size you got? The dealer said it was 24" overall, 18" can, the can is 4" tall and 10 or 12" wide. Is this correct. Thanks.

Does anybody have this muffler or looked into it? WLK-17224 Dynomax Race Mufflers $73.95 Pros-cons? This is a 3.5" in and out and 21" long.

[ 04-09-2003: Message edited by: Maverick ]</p>

[IndigoDually]

Mav, I just called a couple of local guys and got prices of $130 and $155. That's just the muffler, no clamps.

John

[Maverick]

Thanks. I just called Flowmaster as this muffler was not listed on their web page. It retails for $161.00. Boy am I getting ripped off. I hate it! Everyone takes you to the cleaners in Alaska. I found the same muffler at Summit Racing for $111 and change. I also found that Dynomax Race one for $73.95 there also. Now they want to charge a $24.00 handling fee for stuff overseas and a minumum $46 2nd day air. I'll have to call to see if they decair Alaska overseas or not. This is one of the reasons why I am out of here come May. I am taking a trip from Alaska to the Grand Canyon and then across Texas to Springfield, MO area and buy a house. I'll have to stop at Mdrag's house for sure.

[ 04-09-2003: Message edited by: Maverick ]</p>

[mtomac]

I bought mine thru summit racing. I'll double check the inlet and outlet (center or offset) and get measurements in the morning.

[Jelisfc]

Mav, I think you are SOL on the shipping. I checked UPS. They don't ship ground to your zip code. Summit's rates are pretty good. Fed Ex's ground rate for 50 lbs is $85.00.

I'd hold off until your trip and pick it up in the states somehow.

[mtomac]

offset inlet, offset outlet muffler body is 22" long inlet is 3" long and outlet is 3" long = total length 28"

[ 04-10-2003: Message edited by: Micheal Tomac ]</p>

[Idle_Chatter]

Woundedbear, ask and you shall receive. I just put up a folder of photos. Look for "mufflerectomy" folder in the pics link below (looks like I need to grind down those welds and shine that baby up now that the weather's better!) I installed it just before Christmas on the ground in my driveway before heading out to Florida for the Holidays.