Our New 2012 PRHT SS Project....

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Chuck H
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Re: Our New 2012 PRHT SS Project....

Post by Chuck H »

Agree this is the most exciting NC exhaust product in quite a while! Like Jim, I've been dying to try a Helmholtz resonator to help with drone, but never had the resources to develop one.

Now I just need to figure out whether it can be adapted to work with the PPE long tube header. I wonder if one could create a Franken-midpipe by cutting this one just downstream of the 2nd O2 sensor bung and welding on the PPE cat and flange to get the best of both worlds.
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njaremka
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Re: Our New 2012 PRHT SS Project....

Post by njaremka »

Beautiful!! I'd like to hear back to back to back comparisons of OEM Mid - Resonated Mid - Hemholz Mid with a RoadsterSport 2 on the back :D
Brian
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Re: Our New 2012 PRHT SS Project....

Post by Brian »

njaremka wrote:Beautiful!! I'd like to hear back to back to back comparisons of OEM Mid - Resonated Mid - Hemholz Mid with a RoadsterSport 2 on the back :D
Thanks for the feedback guys. I will get some videos up when I get the chance. It is going to revolutionize my recommendations. Prior to today I could never recommend a performance header be used with any muffler other than our RoadsterSport SuperQ muffler. Now I find choices like the Street Single and RoadsterSport2 can be fun with a performance header in a way they were not before because those units could not kill the drone coming down the system.
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jboemler
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Re: Our New 2012 PRHT SS Project....

Post by jboemler »

I did spot the support ring, but I question whether it's enough. Time will tell I guess. When do you figure on posting sound clips?
Brian
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Re: Our New 2012 PRHT SS Project....

Post by Brian »

jboemler wrote:I did spot the support ring, but I question whether it's enough. Time will tell I guess. When do you figure on posting sound clips?
You and I could both hang from that bracket, laser cut stainless plate used on end with over a quarter inch to half inch of meat for support at all points, it's massively overkill...and will hold the 3 pound Helmholtz chamber for a million years.

Yes, will get some videos going when we can, been crazy here with projects lately.
Brian Goodwin
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dmicah
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Joined: Wed Aug 15, 2012 12:02 pm
Location: Seattle

Re: Our New 2012 PRHT SS Project....

Post by dmicah »

Hey Brian, any thoughts about impact on horsepower relative to stock or your original midpipe?
Verwah
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Re: Our New 2012 PRHT SS Project....

Post by Verwah »

Do you have a number for the weight penalty of this mid-pipe versus the other version? If I used the new mid on a GWR header/RSII(or SQ) system would it still weigh less than stock?
Chuck H
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Re: Our New 2012 PRHT SS Project....

Post by Chuck H »

The Helmholtz resonator looks to be just about exactly the same size as the regular in-line one, so the main difference is the extra 18" of pipe that runs next to it. 2.5" stainless exhaust pipe weighs 0.9 lbs/foot, so that section of pipe weighs about 1.5 lbs.

If the regular midpipe resonator is an empty expansion chamber, then this one probably weighs almost 2 lbs more, with the additional pipe, mounting bracket, and inlet to the resonator. If the regular midpipe resonator is more like a glasspack with a perforated tube and sound absorbing material inside, then I'd guess the difference is less than a pound.
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Brian
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Re: Our New 2012 PRHT SS Project....

Post by Brian »

Chuck got it right, normal big packed resonator uses high density packing so weight difference is close to nothing since the Helmholz chamber is empty. You can't see it on the dyno, nothing running through it, etc.
Brian Goodwin
Good-Win Racing
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colt45
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Re: Our New 2012 PRHT SS Project....

Post by colt45 »

re Resonator:

It's not real without sound clips! Panting in anticipation! :mrgreen:

How many more dB is it louder at WOT and say 4k+ than the stock midpipe? I have a Q muffler and no other exhaust mods, yet. As it's aged, the boom has gotten louder, but it has always had a delicious sound revving with my foot in it, especially with the baffles out.

Oh! I found the videos! Cool! Curiously, you didn't let the RPM fall far enough to get to the worst resonance RPM of my car, 1750 indicated. What does it sound like there?

Last week, I got to hear a Miata with your headers, mid-pipe and Roadster Sport single muffler. How does the sound of the Helmholtz mid-pipe and the RS SuperQ sound in comparison while accelerating, both loudness and tone?
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