Pelican Parts Forums - Which Muffler? Dynomax, Magnaflow, M&K

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Has anyone tried 2 of these
Ultra Floâ„¢ Welded Round - Centered / Centered Muffler - P/N: 17230 - DynoMaxÂ® Performance Exhaust
simply stacked one above the other, keeping the exhaust banks separate at all times.

My engine appears to be very sensitive to mufflers.

As previously mentioned, the exhaust shop to fit this did it incorrectly first, by plumbing both headers to fire into the same port in the muffler.. the 17231 is a straight through (no x pipe) so the exhausts were head butting each other, and then being forced through the perforated tube, through the packing, and into the other perforated tube to find the exits. Here is a pic of how NOT to install a 17231
https://i.imgur.com/jG8ChAm.jpg?1

Funnily, the car drove ok . but it was soon fixed. The video a few posts back, is of the 17231 after it was re plumbed correctly. However, I noticed one tip sounded a lot raspier than the other. So I cut it open to find this:http://forums.pelicanparts.com/uploa...1553294525.jpg

I should add, that I am experiencing a vibration at certain rpm, noticably between 2000 and 3000 rpm.
The first Dynomax 17552 did it, and then after making the x-pipe section better sealed, it improved, but was still there.
The 17231 also does it.. on closed throttle on the overrun, as the rpm falls through 3000, it starts to vibrate and gets worse approaching 2000 rpm, but then it smooths out.

Well I repacked my 17231 with glass and closed the muffler back up.
The sound is now much more tame at idle, and definately not loud at all. At full WOT, and above 3000 rpm, it is glorious and pulling really hard. This is the best performing muffler I have used so far.
But the vibration between 2000 and 3000 is unbearable. It's like sitting on top of a washing machine that is unbalanced, and making its way across the laundry!

However, if I crack open the throttle just a tad, it all goes away.

Is this reversion I am experiencing?

I was totally shocked, that repacking the muffler, made such a massive difference to the vibration I am experiencing.
Engine is mounted using stomski engine mounts which I believe are fairly stiff.
I can sit with the car stationery, clutch in, and as a blip the throttle to rev the motor, it is just vibrating and shaking so much.

I took the muffler off, and drove around the block with just the open headers and intermediate tubes.. no muffler. Yes, it is stupid loud, but the engine did not shake or vibrate at all. OPen throttle, closed throttle, at all the rpm points where the muffler makes it shake, the engine was smooth with no muffler.

Very strange.

Last effort; I just had a local shop fit up a magnaflow 14386.. they have an x-pipe arrangement.
Picked up the car yesterday and first test was revving it in the car park.. almost perfectly smooth.
The sound is deeper, and to me, I think the top end is not as strong, but for the first time, the car is drivable without trying to shake my fillings out of my head.
Yes, it still feels a little "fluffy" around 2500 rpm... but whether I am accelerating or on the overrun, the vibration is minimal and I suspect installing a set of oem engine mounts might make it fine.
It does not pull perfectly cleanly, till reaching 3000 rpm..

Do I have reversion and is this something than can be tuned out?

Video taken this morning running the Magnaflow.
https://www.youtube.com/watch?v=gws5r6SzbA4

Quote:

Originally Posted by mikedsilva (Post 10401086)

…..Do I have reversion and is this something than can be tuned out?

Mike,
What's your Lambda reading showing in the range where the engine is running rough?

Is it actually misfiring in this range or doing something else? (Which may give you a false Lambda reading anyway.)

Are you able to richen it up in this part of the VE table to see what effect it has?

Love ya work! Keep posting!

PS: Have you thought about using your ECU to control a bypass valve in your exhaust? Quiet and mild mannered at less than say 80% WOT and Stormin' Norman above!

think the problem is linkage on butterflies between sides. He will end up sticking with the Dynomax is my bet. William Knight

I have a similar setup except my cams and pistons are "stock" 3.0 items. I don't have this vibration issue. I used muffler straps instead of welding a bracket to the muffler like you did Mike. I also have four new, but factory mounts. In a previous life, I used solid mounts on a car I had modified and it vibrated my fillings out!
Some of the issue might be from the way your mounting the exhaust, not allowing it to move at all, and some might be from the near-solid mounts you have.

I emailed you earlier last week regarding the aem crank and cam sensor causing issues at a certain resonance for me dropping the ign timing a good 10-15 degrees. The test for this is simple: lock the timing to 25° in the software and rev the motor thru the rev range while verifying with timing light. It should stay static at 25°. Mine very clearly dropped to 12° or so at 4500 rpm. Yours might be doing something similar at a different rpm.

We stepped up the muffler and piping size and re-ran my car. Now we meet or exceed open headers. Picked up another huge amount of power under the curve in two big areas!http://forums.pelicanparts.com/uploa...1554253249.jpg
http://forums.pelicanparts.com/uploa...1554253249.jpg
http://forums.pelicanparts.com/uploa...1554253249.jpg

BBW and SBW are BIG and SMALL Barry White setups

I thought I could keep the 5+ Mikes straight.

Now A couple of Barry Whites

This is confusing.

What’s a Barry White again?

Big or Small. BW seems to be very good.

Its a muff setup we have been messing with and developing with Hoover at TurboHoses R&D. We are now working on an "R" outlet version for a pile of 3.2SS cars we have kicking around here. All are currently running M&Ks. We shall see

How do I get one? what headers are you running on your motors?

Mike. We will verify results with the R outlets on a 3.2. But we will be using the small Barry muffs for those. The large ones won’t fit in that config. This will happen in the next week or so and we will make 10 of them. 4 are already spoken for

I have the big Bursch on my car these other 3.2ss cars all have SSIs

Love the sound of that. I made something similar years ago for my racecar. It shrieked in grand fashion.

I'd have to agree about poor quality of the welds. It's rather pathetic that they shipped that to a customer!

New complete exhaust that is the answer

I have a prototype full stainless system that give everyone what they want.3 sizes. 1 1/2 & 1 5/8 & 1 3/4 I.D.It is quiet with no drone and barks when necessary.Heat is an option for the thermally challenged.Pictures in next 2 weeks.Fred

Quote:

Originally Posted by LeftCoastErik (Post 10414429)

Shot you a PM inquiring how I could get ahold of one of your mufflers. Above you noted 4 were spoken for of the 10 you are producing. My 3.6 needs some love. :)

Does everyone understand that posting exhaust examples depends on the playback level of individual computers? Without a reference, users can play back exhaust notes at any level.

For example, this is approximately 110 dB measure with an iPhone dB app, NoiSee.
https://www.youtube.com/watch?v=kQ8riM4qNwE&t=37s

Sherwood

Quote:

Originally Posted by KNIGHTRACE (Post 10458166)

Motor sounds good.

I'm experimenting with a 997 rear muffler... nice to drive on the road, no resonance etc. Has a "dirty" sound to it down low.. getting a couple small resonators added to tone it down. Should be good.

But no, doesn't feel as good as the Dynomax 17231..