Re: B-body Hemi mufflers performance vs. aftermarket
[Re: 6PAX]
#227350
02/17/09 08:10 AM
02/17/09 08:10 AM
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Joined: Feb 2004
Posts: 470 Big Chicago
amixon
mopar
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mopar
Joined: Feb 2004
Posts: 470
Big Chicago
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I have to take a stab at this, you mean the original 1968 style mufflers? I would say the restriction would be very high and the flow capacity of the factory style stuff would be very low. Scotty Brown used to have a flow chart with that stuff up there, but I can not locate anything similar to that today. I did find this little site it has some information on flow testing but they only go up to a 2.5 pipe size...hope it helps some http://www.broaderperformance.com/muffler_flow_tests.htm I liked the sound quality of the DynaMax, they tend not to drone like the Flowmasters and such. What is it you are looking to do?
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Re: B-body Hemi mufflers performance vs. aftermarket
[Re: 6PAX]
#227353
02/17/09 08:24 PM
02/17/09 08:24 PM
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Joined: Apr 2005
Posts: 15,134 Kelowna, B.C. Canada
DPelletier
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I Live Here
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Many of the top runners at the Pure Stock drags ( www.purestockdrags.com ) use Walker/Dynamax Ultra Flows so I ordered a set of 2 1/2" Ultra Flows to go with my 2 1/2" mandrel bent TTI exhaust system. The Ultra flows perform very similar to the Hooker Max Flows in the chart posted above. This isn't surprising as they share the straight-through design. The stainless ultraflows are crimped similar to the stock mufflers. They are also available in aluminized versions, but then they use welded construction. You won't fool anybody into thinking the s/s ultraflows are NOS mufflers, but if you turn them so the stamped "dynomax" logo is facing the floorboards, then they look semi-correct. I'm told they are fairly quiet, but I haven't fired mine up yet. If you want something that looks sorta stock, but performs way better then I would recommend the ultra flows. They are a little pricey, though. http://www.dynomax.com/products/ultrafloss.htmlDave
1970 Super Bee 440 Six Pack
1974 'Cuda
2008 Ram 3500 Diesel
2006 Ram 3500 Diesel
2004.5 Ram 2500 Diesel
2003 Ram 3500 Diesel
2006 Durango Limited
[url] http://1970superbee.piczo.com [/url]
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Re: B-body Hemi mufflers performance vs. aftermarket
[Re: gch]
#227355
02/18/09 01:20 PM
02/18/09 01:20 PM
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Joined: Jan 2004
Posts: 9,066 Eugene, Oregon
minivan
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master
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Eugene, Oregon
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Quote:
Check with accurate ltd.I believe he produces resto correct "hemi" mufflers with stock and improved flow as well.
I have Accurates "improved flow" hemi mufflers on my 67 coronet with a 440.. Just a little louder than stock..
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Re: B-body Hemi mufflers performance vs. aftermarket
[Re: 6PAX]
#227357
02/18/09 05:20 PM
02/18/09 05:20 PM
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Joined: Jul 2007
Posts: 271 MO, USA
Tom Hand
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enthusiast
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Here are typical after market replacement HEMI-sized mufflers.
Last edited by Tom Hand; 02/18/09 05:22 PM.
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Re: B-body Hemi mufflers performance vs. aftermarket
[Re: Tom Hand]
#227358
02/18/09 05:24 PM
02/18/09 05:24 PM
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Joined: Jul 2007
Posts: 271 MO, USA
Tom Hand
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Look at the stockers in the lower section of this chart. 21848 is the HEMI sized muffler. The ones from Waldron and others will flow better but this data will give you an idea of the stock replacements and how they react.
Note something else: it is easy to see why the old Corvair turbo muffler worked, in fact, they flow about the same as today's leading chambered muffler with significantly less sound levels.
Last edited by Tom Hand; 02/18/09 05:28 PM.
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Re: B-body Hemi mufflers performance vs. aftermarket
[Re: Tom Hand]
#227359
02/18/09 08:12 PM
02/18/09 08:12 PM
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Joined: Apr 2005
Posts: 15,134 Kelowna, B.C. Canada
DPelletier
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WOW, thanks for the great info! I'm even happier with my Ultra flow decision based on that info. Cheers, Dave
1970 Super Bee 440 Six Pack
1974 'Cuda
2008 Ram 3500 Diesel
2006 Ram 3500 Diesel
2004.5 Ram 2500 Diesel
2003 Ram 3500 Diesel
2006 Durango Limited
[url] http://1970superbee.piczo.com [/url]
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Re: B-body Hemi mufflers performance vs. aftermarket
[Re: DPelletier]
#227360
02/18/09 08:24 PM
02/18/09 08:24 PM
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Joined: Jan 2003
Posts: 9,924 Weddington, N.C.
Streetwize
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Ultraflows can be fairly mellow at idle on milder motors without a lot of compression and especially without a lot of cam overlap. When you go big cubes, high compression and long duration they tend to get a bit louder. I went with the Dynomax Hemi Mufflers because with big cubes, 12:1 and a big cam I felt the Ultraflows would be a "touch too much" for the neighborhood and town I live in. The Hemis are 3" all the way through and flow well, at least on par with the shorties. I believe the OEM style Hemi's are 2 1/2 to 2 1/4 ID, but I believe Accurate may make a 3" internal. Here's a sound clip with 3" dmax Hemis: http://www.youtube.com/watch?v=jd8GeXYYkKU&feature=channel_page
Last edited by Streetwize; 02/18/09 08:27 PM.
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Re: B-body Hemi mufflers performance vs. aftermarket
[Re: Streetwize]
#227361
02/18/09 08:31 PM
02/18/09 08:31 PM
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Joined: Apr 2005
Posts: 15,134 Kelowna, B.C. Canada
DPelletier
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I Live Here
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Quote:
Ultraflows can be fairly mellow at idle on milder motors without a lot of compression and especially without a lot of cam overlap. When you go big cubes, high compression and long duration they tend to get a bit louder.
I went with the Dynomax Hemi Mufflers because with big cubes, 12:1 and a big cam I felt the Ultraflows would be a "touch too much" for the neighborhood and town I live in. The Hemis are 3" all the way through and flow well, at least on par with the shorties. I believe the OEM style Hemi's are 2 1/2 to 2 1/4 ID, but I believe Accurate may make a 3" internal.
Here's a sound clip with 3" dmax Hemis:
http://www.youtube.com/watch?v=jd8GeXYYkKU&feature=channel_page
That sounds great!
I was going by what the other guys with similar setups were saying; 440, 10.75:1, stock(ish) legal cam, iron manifolds = fairly quiet, esp. at idle.
If not......the only neighbors I have are deer!
Cheers, Dave
1970 Super Bee 440 Six Pack
1974 'Cuda
2008 Ram 3500 Diesel
2006 Ram 3500 Diesel
2004.5 Ram 2500 Diesel
2003 Ram 3500 Diesel
2006 Durango Limited
[url] http://1970superbee.piczo.com [/url]
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Re: B-body Hemi mufflers performance vs. aftermarket
[Re: Streetwize]
#227362
02/19/09 09:51 AM
02/19/09 09:51 AM
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Joined: Jan 2003
Posts: 16,123 Grand Haven, MI
patrick
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Quote:
Ultraflows can be fairly mellow at idle on milder motors without a lot of compression and especially without a lot of cam overlap. When you go big cubes, high compression and long duration they tend to get a bit louder.
I went with the Dynomax Hemi Mufflers because with big cubes, 12:1 and a big cam I felt the Ultraflows would be a "touch too much" for the neighborhood and town I live in. The Hemis are 3" all the way through and flow well, at least on par with the shorties. I believe the OEM style Hemi's are 2 1/2 to 2 1/4 ID, but I believe Accurate may make a 3" internal.
Here's a sound clip with 3" dmax Hemis:
http://www.youtube.com/watch?v=jd8GeXYYkKU&feature=channel_page
those are the dynomax 17769's I presume? the large body ones? I have one in a big single config on my 5th ave with a dynomax race bullet in the tail and it's not bad.
if you are looking for a little quieter or don't need the 3" straight through, the 17748 & 49's are the 2.5" version.
adding the race bullet in my tail as a resonator made a big difference in knocking the noise level down, especially in the interior of the car.
1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!*** 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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