Stoddard's new muffler

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Jerry Kolb
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Stoddard's new muffler

#1 Post by Jerry Kolb »

Anyone have any experience with Stoddard's new stainless muffler that was designed by Magnaflow? All information would be appreciated as I am contemplating purchase.

Thanx

Jerry

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Neil Bardsley
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Re: Stoddard's new muffler

#2 Post by Neil Bardsley »

I saw a video that PRS posted on youtube of a Magnaflow exhaust on a 356 they had worked on. Contact Mike Smith on here or Paul Smith at the shop

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C J Murray
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Re: Stoddard's new muffler

#3 Post by C J Murray »

neilbardsley wrote:I saw a video that PRS posted on youtube of a Magnaflow exhaust on a 356 they had worked on. Contact Mike Smith on here or Paul Smith at the shop
That must have been the car with an engine I built a few years ago. They tried the system but decided to remove it for reasons best explained by them since I don't know the details. On the other hand we have a regular poster here who has one on his car and he may wish to chime in.
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C J Murray
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Re: Stoddard's new muffler

#4 Post by C J Murray »

I watched the video. Is it safe for the cameraman to balance himself on the engine lid? :wink: I was shocked :shock: to see oil spots on the PRS driveway! :P

https://www.youtube.com/watch?v=fbxj3mfMsxE
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Jeffrey Leeds
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Re: Stoddard's new muffler

#5 Post by Jeffrey Leeds »

IMG_0497.JPG
I have the Stoddard/Magnaflow muffler which I installed July 29, 2018. This muffler replaced a GDP Twin Tip muffler that had been in service for 3 years with a good experience. The reason for the change was to try something new and more importantly to return my car to it's previous configuration where the exhaust outlets exited through the rear valance openings, rather than under the valance as does the GDP TT. When my car was restored by Bob Grigsby in the early 90's he left the front and rear bumper over-riders off preferring a more "continental" look, which I also prefer.

Anyway, this was a perfect opportunity to do back-to-back chassis dyno runs to compare/contrast two the two mufflers, which is displayed nearby. The BLUE trace is the Stoddard/Magnaflow muffler and the RED trace is the GDP. The engine is a stock S90 with approximately 45000 miles since it was rebuilt. There is a dip in torque through the mid-range which is not noticeable in my real world driving, but we intend to try additional development next year to see if that dip can be mitigated.



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John Clarke
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Re: Stoddard's new muffler

#6 Post by John Clarke »

Well, the figures speak for themselves! Down on torque in that vital mid rev range from 2500 -4000rpm where most of us spend a lot of time!
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Neil Bardsley
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Re: Stoddard's new muffler

#7 Post by Neil Bardsley »

Jeffrey Leeds wrote:
IMG_0497.JPG
I have the Stoddard/Magnaflow muffler which I installed July 29, 2018. This muffler replaced a GDP Twin Tip muffler that had been in service for 3 years with a good experience. The reason for the change was to try something new and more importantly to return my car to it's previous configuration where the exhaust outlets exited through the rear valance openings, rather than under the valance as does the GDP TT. When my car was restored by Bob Grigsby in the early 90's he left the front and rear bumper over-riders off preferring a more "continental" look, which I also prefer.

Anyway, this was a perfect opportunity to do back-to-back chassis dyno runs to compare/contrast two the two mufflers, which is displayed nearby. The BLUE trace is the Stoddard/Magnaflow muffler and the RED trace is the GDP. The engine is a stock S90 with approximately 45000 miles since it was rebuilt. There is a dip in torque through the mid-range which is not noticeable in my real world driving, but we intend to try additional development next year to see if that dip can be mitigated.



Jeff
but fast enough to blow luggage off the back of the car?

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Re: Stoddard's new muffler

#8 Post by Jeffrey Leeds »

For Sure !
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Gary Cox
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Re: Stoddard's new muffler

#9 Post by Gary Cox »

Curious if the curves shown is an average of several dyno runs for each muffler or just a single run for each? The dip might be mitigated by simple statistical analysis....
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Jeffrey Leeds
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Re: Stoddard's new muffler

#10 Post by Jeffrey Leeds »

Each muffler had two runs and the best run of each muffler is displayed.
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Ron LaDow
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Re: Stoddard's new muffler

#11 Post by Ron LaDow »

Jeffrey Leeds wrote:Each muffler had two runs and the best run of each muffler is displayed.
You can infer the Y-scale values from the max power numbers, so the best showed what looks like 3HP gain (say a bit over 5%) for a limited range. It's not nothing, but it would take a very finely-tuned butt to notice the difference in use.
It'd be nice to see the other runs and the torque curves.
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Re: Stoddard's new muffler

#12 Post by Adam Wright »

Ron LaDow wrote:
Jeffrey Leeds wrote:Each muffler had two runs and the best run of each muffler is displayed.
You can infer the Y-scale values from the max power numbers, so the best showed what looks like 3HP gain (say a bit over 5%) for a limited range. It's not nothing, but it would take a very finely-tuned butt to notice the difference in use.
It'd be nice to see the other runs and the torque curves.
Yeah, but it's so hard to find someone who knows how to tune butts these days, I think it is truly becoming a lost art...
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Martin Benade
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Re: Stoddard's new muffler

#13 Post by Martin Benade »

Does the GDP muffler equal the OE design for torque/power?
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Re: Stoddard's new muffler

#14 Post by James Learmonth »

Does the Stoddard muffler clear the Pre Mat FullFlow filter?

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DonCichocki
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Re: Stoddard's new muffler

#15 Post by DonCichocki »

Yes. '65 C stock exhaust with Pre Mat full flow adapter.
Sorry, I must correct my post.
The stock Dansk muffler clears no problem. No clue about Stoddard's "new muffler".

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