[nmoreilly]

Looking for thoughts on the quietest, best flowing stainless muffler. 535 IAII / Dougs 1 7/8 inch round port headers with 3 1/2 inch collectors. Stainless, 3 inch system with cross pipe but will exit to the Pypes 2.5 inch "trumpets" (car is a 66 GTO)

Thanks in advance

Noel

[steve25]

I do not think you will find any such thing avalible on the market, especially with 500 + cube motor even idling through them.
You may need to hang resonators out back on each side of the gas tank dependant on what your tolerance for Db level is.

[nmoreilly]

Originally Posted by steve25

I do not think you will find any such thing avalible on the market, especially with 500 + cube motor even idling through them.
You may need to hang resonators out back on each side of the gas tank dependant on what your tolerance for Db level is.

not going to be easy I guess. Was leaning towards the 20 inch Dynomax super turbos but their aluminiumized and not stainless. By the way original post should be H-Pipe and not cross pipe

[OLDFLM72]

I went through the exact same dilemma and ended up getting the Dynomax Super Turbos and had them ceramic coated... Hooker has a new 3" stainless muffler but I'm not sure if it has the same straight through design (louder) as the Pypes/Magnaflow/Borla etc.

For me the Super Turbos were the perfect choice! They may have cost a little power but they dropped my idle levels by 12 Dbs at idle and don't drone at all! Ceramic coated Hedman 28150s with full 3" stainless mandrel exhaust out the back.

There's a thread on here about the switch to the Super Turbos and the Db testing I did... HTH

[HWYSTR455]

The Super Turbo last pretty long, and are certainly the most quiet that I've heard.

I ran the non-stainless Xlerator Goerich mufflers on the LeMans, they are almost as quiet as the Super Turbos, except at WOT. At WOT, they are louder than the super turbos. I like the sound of them, no drone, and you can talk to the person next to you at cruise.

They do make them in stainless, but I personally have no experience with them. They make them in a few sizes, up to 22", think I had the 18s.

http://www.apexhaust.com/product/per...ance-mufflers/

Catalog:

http://www.apexhaust.com/wp-content/...talog_XP10.pdf

You can poke around, many like them, and they flow as well or almost as well as the super turbos.

.

[tom s]

Noel,I have Hushpowers by flomasters on two of my cars and love them.They are stainless,way more quiet than the 2 chamber flomasters.Might not be as quiet as you might want but I would use them for any car I get in the future.Tom

[fastekibeast]

My vote goes to Borla XR-1!! I have run three summer with those in my -69 GTO
Really great mufflers, nice low tone at idle and when reach up higher rpm real old school scream!

Janne

[Cardo]

I also ran the Gerolich non stainless X-celerators and agree. Quiet at idle/ cruise and no drone. I am leaning hard toward running them again on my current project.

[nmoreilly]

Very helpful guys, thanks to all !

[tpssonic]

Stainless VTs. Quite at idle and cruise- no drone at all. You will take attention at full wail, however. I run the 3" size.

[nmoreilly]

Originally Posted by tpssonic

Stainless VTs. Quite at idle and cruise- no drone at all. You will take attention at full wail, however. I run the 3" size.

Thanks. VT's, the Ultraflows ?

[OLDFLM72]

The bigger the case the more quiet any muffler will be... 14" vs 20-22". So I'd run the biggest (longest) muffler under your car as will fit.

FWIW Lee Atkinson ran the Goerlich's on his 11.3-second 67 Firebird and loved them... and... Jim Hand ran the 20" 17749 Dynomax Super Turbos on his wagon for years.

http://www.pontiacstreetperformance....p/exhaust.html

[crazycarlo]

I just installed Jones Maxflows straight through mufflers on my mustang. They are ALOT quieter then I'd like and they are stainless. Best part is they are about $40 each.

[nmoreilly]

Originally Posted by OLDFLM72

The bigger the case the more quiet any muffler will be... 14" vs 20-22". So I'd run the biggest (longest) muffler under your car as will fit.

FWIW Lee Atkinson ran the Goerlich's on his 11.3-second 67 Firebird and loved them... and... Jim Hand ran the 20" 17749 Dynomax Super Turbos on his wagon for years.

http://www.pontiacstreetperformance....p/exhaust.html

The 20 inch Dynomax were the ones I'm considering the I think the Axelerators come in a 22 inch, not the Dynomax's though

[craigs69]

Originally Posted by fastekibeast

My vote goes to Borla XR-1!! I have run three summer with those in my -69 GTO
Really great mufflers, nice low tone at idle and when reach up higher rpm real old school scream!

Janne

These are very sweet sounding mufflers, but not quiet.

[ta man]

Another vote for Dynomax Super Turbos,like others have said the biggest you can fit.

If your exhaust isn't bought yet an X pipe will drop the decibels also.

[tpssonic]

Originally Posted by nmoreilly

Thanks. VT's, the Ultraflows ?

They are called Dynomax VTs. "VT" stands for valve technology where a spring-loaded plate opens and closes due to back-pressure. At WOT they are basically a straight pipe. I have had them for a couple of year now and really like them. O-drone.

I also run an X-pipe' All exhaust are 3" and stainless, with wide-band bung in each collector.

I meant to say "quiet" at idle in my earlier post.

[HWYSTR455]

The term 'quiet' is a matter of opinion, you really need a reference to DBs. Hence why Jim Hand did the 'original' muffler test. It's not that current, but is still a viable reference:

http://www.pontiacstreetperformance....p/exhaust.html

.

[Lee]

Originally Posted by nmoreilly

The 20 inch Dynomax were the ones I'm considering the I think the Axelerators come in a 22 inch, not the Dynomax's though

As mentioned, I ran the big case Xlerators on both my '67 Firebird and also on my '69 Falcon wagon.

Even at WOT, the long case is STILL shockingly "non-noisy" I had my wagon at a few bigger local races, and people thought it was a 14/15-second car when it was driving through the pits. Friends of mine in the stands still talk about the people around them freaking out when it ran 10's.

On the Firebird, I dropped almost a full tenth and gained just over 1mph, when I replaced the 3" Flowmasters with the 3" large case Xlerators (much thanks to Tom Hand, for his guidance and assistance on that change!). The noise reduction was even more impressive.

[nmoreilly]

Originally Posted by HWYSTR455

The term 'quiet' is a matter of opinion, you really need a reference to DBs. Hence why Jim Hand did the 'original' muffler test. It's not that current, but is still a viable reference:

http://www.pontiacstreetperformance....p/exhaust.html

.

Its a great article, and I am blessed to also have Jim's book