Posted By: JohnRR
dynomax 17747 ? - 08/04/14 10:57 PM
Anyone with a 2 1/4 system running these ? They are listed as center in offset out and I want to run them in reverse on a 69 B body ???
dynomax 17747 ?
Posted By: Dave440
Re: dynomax 17747 ? - 08/04/14 11:11 PM
Not using them myself but have been looking into a new system and done the research. They are reversible.
http://www.dynomax.com/super-turbo-centered-offset-576.html
http://www.dynomax.com/super-turbo-centered-offset-576.html
Posted By: JohnRR
Re: dynomax 17747 ? - 08/04/14 11:38 PM
Thanks Dave , I missed that part on the web listing
I did call dynomax and ask because I needed to place the order ASAP.
I did call dynomax and ask because I needed to place the order ASAP.
Posted By: 62maxwgn
Re: dynomax 17747 ? - 08/04/14 11:43 PM
John,been running that muffler on my bird since I've owned it,over thirty years,wouldn't use anything else.B-body is one of the applications,why would you want to reverse it? Also if you buy keep your receipt,you'll never have to pay for a replacement! 
Posted By: Dave440
Re: dynomax 17747 ? - 08/04/14 11:43 PM
YW John... Overlooking something right in front of you? I've never done that!! 
62Maxwagon...i've always wondered something about turbo mufflers. Wouldn't Offset/Offset flow better than Center/Offset? Maybe this would be better for a separate post and an opinion poll LOL... but it just seems logical looking at the cutaways of the tube layout, flow directors (if any) and internal perforated tube.
62Maxwagon...i've always wondered something about turbo mufflers. Wouldn't Offset/Offset flow better than Center/Offset? Maybe this would be better for a separate post and an opinion poll LOL... but it just seems logical looking at the cutaways of the tube layout, flow directors (if any) and internal perforated tube.
Posted By: 62maxwgn
Re: dynomax 17747 ? - 08/04/14 11:55 PM
Quote:
YW John... Overlooking something right in front of you? I've never done that!!
62Maxwagon...i've always wondered something about turbo mufflers. Wouldn't Offset/Offset flow better than Center/Offset? Maybe this would be better for a separate post and an opinion poll LOL... but it just seems logical looking at the cutaways of the tube layout, flow directors (if any) and internal perforated tube.
On a b-body you have to run then side inlet,center outlet,asked that question a long time ago and Walker says there is no difference.
Posted By: bschargerse
Re: dynomax 17747 ? - 08/05/14 12:01 AM
I had these mufflers on my '66 Newport 383 with the factory log manifolds and a full 2.25" system. No crossover pipe. There was a slight drone to it at cruising speed, but not too bad. It seemed as the muffler got older the less noticeable the drone.
Posted By: BSB67
Re: dynomax 17747 ? - 08/05/14 12:49 AM
Ran the 747s ( more than one set) for a bunch of years on the 67. Worked fine. Went 12.80s and 90s at 109 with pretty stock motor, FWIW
Posted By: Dave440
Re: dynomax 17747 ? - 08/05/14 01:23 AM
"Walker says there is no difference."
Maybe negligible to them but there has to be a difference of some sort. I ran sonic turbo's for years offset/center and had no problem but always wondered about the flow.
I used the Dynomax offset x2 cutaway here and added exhaust (red/blue) to illustrate how it flows nicely with an offset setup and dual flow directors. I modified the cutaway to make a center/offset version which they don't show on their site. The exhaust has to dance around the chamber with the center tube before finding a way out (illustrated in blue). Center/offset obviously works and if the exhaust system can only acomodate that type of muffler then that's what we're stuck with...but I have seem some mopes with custom exhaust running offset x2. Be interesting to see a dyno showing the difference. Maybe worth a few horsepower?
Maybe negligible to them but there has to be a difference of some sort. I ran sonic turbo's for years offset/center and had no problem but always wondered about the flow.
I used the Dynomax offset x2 cutaway here and added exhaust (red/blue) to illustrate how it flows nicely with an offset setup and dual flow directors. I modified the cutaway to make a center/offset version which they don't show on their site. The exhaust has to dance around the chamber with the center tube before finding a way out (illustrated in blue). Center/offset obviously works and if the exhaust system can only acomodate that type of muffler then that's what we're stuck with...but I have seem some mopes with custom exhaust running offset x2. Be interesting to see a dyno showing the difference. Maybe worth a few horsepower?