Mazda Talk Forums

Hey Brian, any thoughts about impact on horsepower relative to stock or your original midpipe?

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?

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.

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.

re Resonator:

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

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?

Curious about impact on HP, if any. Also, any thoughts on whether this part will be better, worse, or the same as your original midpipe WRT clearing the IL Motorsport and other braces? Thanks!

No impact on HP. No change in fitment with braces.

My first post.

Brian,

Thank you. Thank you. Thank you.
I am really impressed with your dedication to product development and your willingness to share information on the forum. Been following the progress of Our New 2012 PRHT SS Project so I can use it as a template for my car.

Just purchased my first 2011 Miata on 9/3/15 as a daily driver. It had no muffler on it. Straight pipes. Put a Super Q muffler on it quickly.

It could have taken me months to research and determine what parts or mods to do to my car. You have made my decisions so easy. Within 30 days it will be done….mostly.

I was at Rocky’s Miatomotive on 9/19 having him install the Progress sway bars, Progress springs, Koni Sport shocks. What a big difference in ride quality.

Thank you for the ride in the 2012 PRHT SS Project car last Saturday. What a treat. I was not expecting that. The RS Helmholtz midpipe you have on the car is really impressive at reducing the drone. The 2500-1500 rpm drone is gone. I am ordering the Roadster Sport street header and RS Helmholtz midpipe next week.

Even my wife is starting to like the Miata now. Really!!! Except for that clutch thingy.

Daniel

More Pics..

This project car is FOR SALE. Current Mileage Just 16,297.

We sold this project car 1.5 year ago... and new owner drove it for 1.5 year and then bought a new Jaguar drop top, so this car is available for sale. Owner is seeking just bluebook for an amazing and nicely prepared PRHT. Contact us if interested and we can put you in touch with the current seller.