oldjag wrote:I don't understand the aversion to adding a little weight. I installed 10 square feet of 80 mil Fat Mat in trunk of my PRHT and only weighed <4 lbs. I would gladly loose 4 lbs. for the improvement in NVH and drone reduction.Well worth it.
I feel the same way, although I would point out that 10 square feet is just the tip of the iceberg. My car probably has ten times that, and it's not really "done". Once you do the Cosworth, you can stop worrying about every pound.
When I restored my 69 mustang GT I installed dynamat style sound deadner in the roof, doors , floor pan and rear wheel wells. then I filled any cavities with the pressed cotton type mat. Added maybe 40 lbs total. The difference it made in the car was amazing. The interior was cooler, road noise was nil and the whole car felt more solid, it was defiantly worth the effort. I know dynamat and some other companies have a spray on deadner which should help some of the sheet metal panels found on the Miata
The explanation that eluviis gave makes perfect sense.
I put Dynamat in my trunk, doors, and on the floor of the cabin. I did it in that order with each spaced a few days apart. I used it for its intended purpose of deadening vibrations, rather than as a sound insulator. By that I mean I cut the mat into small pieces in order to cover intricate areas and didn't necessarily cover every square inch. The trunk (took out the plastic liner) and floor (pulled from the side and from under the center console) were easy and I got good coverage. The doors were a bit more difficult; I did some slight damage taking them apart and it was tough to find places to stick the mat.
In the end the results fell short of what some people had claimed and what I was hoping for. The cabin does seem a little bit quieter and conversations are slightly easier, but it's only a minimal difference. Further, over time I've forgotten there is any difference at all and it just seems loud again. To draw from what eluviis said, I suspect I have further deadened the mid and high frequencies to give the illusion there is slightly less noise, but all the low frequencies are still there.
If I was to do it again, I don't know what I would do. Maybe nothing at all. Or maybe just cover the foot wells, transmission tunnel, and bottom of the trunk. I'd skip the doors, unless you had something special in mind. I'm still open to other ideas though!
(N.B. I have the RoadsterSport headers and mid-pipe with Q muffler. I love the sound when I'm alone and driving aggressively. It's less pleasing on the freeway when I'm trying to have a conversation with my passenger.)
The only material that I'm aware of that is thin yet is effective at reducing low frequencies and overall Db considerably is "mass loaded vinyl." However, that stuff is so heavy that I don't want it anywhere near my Miata. That stuff usually starts at 1/2 a pound per square foot at it's thinnest. More average MLV is 1 or 2 pounds per square foot.
How the luxury companies like BMW and Mercedes soundproof the insides of their cars is beyond me - but then again, their luxury cars (the quiet ones inside) are crazy heavy anyway.
Looking forward to seeing what front splitter you come up with Brian. The NC2 is in need of some options here. Stock front end is kind of weak and right now the only easily available option is the OEM "Appearance Package" lip (which is pretty nice and my backup plan, but would be nice to have another option).
Also wanted to agree with other NC2 owners that there is a sizeable market opportunity if you can get Progress to design an NC2 spring that provides reasonable lowering (1", anything less is not worth it) and with an appropriate firm spring rate for such a drop. As many of us on m.net know, the otherwise really performance-oriented spring (FM) has shown issues with "reverse rake" on the NC2.
Brian wrote: So, for those who don't want to splice wires to complete the install, this fact raises the installed cost to include the header and $88 worth of extension cords. Thus, part of me really hoped that the other style would win the dyno battle because that version can be installed without the cords, but it was no contest on the dyno, longer primary design much stronger.
Hi Brian, question: aren't the actual extension cords too long for the new catted header ? The converter is just a couple inches lower but the cords are done to bring the plugs further into the midpipe.
And it's not clear to me how much gain does the new catted header give compared to PPE catted header. Thanks
The fact that the cords are longer than you need simply means you can route them as you please. As already stated, it was not a close call on the dyno, longer primaries win. Just $88 in cords to enable install of the longer primary design that makes several more pound feet of torque across a broad range of RPMS...that's the cheapest torque you can buy. That means installed cost for the design that makes more torque, will still be about $200 less than the most similar competition.
But as already noted, this assumes you want a bolt in catted header that lives in the space occupied by the factory header. Many want this option. But otherwise, as already noted, our full open RoadsterSport header makes more power for less money....and you locate the sensors to the midpipe.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Maybe this has already been told in the past, but: how to use the RS midpipe with a catted header like the new one: I thought the sensor holes must be sealed by soldering, or maybe not ?
Not sure I understand the question. The RoadsterSport midpipe has two O2 connections...but they arrive with plugs that unscrew. So, you can use one or both as needed. With this header you would use just the O2 connection after the converter.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
