NC DYNO: INTAKE, EXHAUST, MIDPIPE, HEADER, SUPERCHARGER!

Miata Parts, Intakes, Superchargers, Headers, Exhausts, Shocks, Springs, Sway Bars, Brake Kits, Autocross and track mods.
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Brian
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NC DYNO: INTAKE, EXHAUST, MIDPIPE, HEADER, SUPERCHARGER!

Post by Brian »

On a dyno dynamics unit we were stock 130 to 132 at the wheels across several runs (remember that the factory claim of 170 is "crank" horsepower for 2006 and 166 crank hp for 2007 under the new testing procedures). These results are identical to what AEM and Grassroots MotorSports got for stock on their project cars. With AEM intake and exhaust we hit peaks of 145-148 depending on the run...again on a Dyno Dynamics unit. Figure about half that for the AEM intake (which is in line with their claims and dyno charts) and half the exhaust.

Note that the The Dyno Dynamics dyno is an eddy-current dyno, it is not an inertia dyno. Without getting into that debate about what is a "real dyno", just understand that conversion between these types of dynos is rough at best....and it is much preferred to compare apples with apples by doing all before and after tests on the SAME DYNO.

Now to the dynos comparing mods. THREE levels of mods below.

LOWEST line is our best NC dyno run with AEM intake and our RoadsterSport DUALs, a nice gain of about 14-16 horsepower over stock NC.

MIDDLE run adds the midpipe change. This midpipe change was VERY interesting. Did several runs and they all look like this with a very slight loss of 2 peak horsepower but a gain of 5 to 8 Ft/lbs of torque from 3500 all the way past 6000 rpms. This is still a prototype unit but production hopefully by Christmas...

HIGHEST RUN adds in the header. NICE 158.9 hp and 137 Ft/Lbs!! This is Header with our midpipe and exhaust and the AEM intake. Note that the RoadsterSport header does NOT have hookups for O2 sensors, but we sell the extension cords to make this install plug and play. The RoadsterSport midpipe includes TWO O2 sensor bungs, one before and after the catalytic converter to make it easy to relocate the sensors with the optional extension cables to avoid codes. Our RoadsterSport Midpipe uses a massive 18 inch long resonator to keep sound the same despite the gain in flow over the stock unit… but adding header will add a lot of sound. If you like old Italian Fiats and Alfas then you will love the sound of this car with the header, and those with more delicate sensibilities should consider our headers that include a converter in the header itself. Note the interesting comparison with the Grassroots MotorSports project NC Spec Miata; we started with the exact same baseline results and finished almost the same, 2 hp and 2 ft/lbs stronger, all the gains of the full race system without the full race system noise.

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Last edited by Brian on Wed Mar 25, 2009 9:22 am, edited 13 times in total.
Brian Goodwin
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Brian
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Post by Brian »

Image

Midpipe views with monster resonator....and look far enough forward in the second photo and you can see the converter just before the flange to the header.

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Last edited by Brian on Sat Sep 23, 2006 2:56 pm, edited 1 time in total.
Brian Goodwin
Good-Win Racing
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mann
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Post by mann »

NICE. Good to see that there can be more to had even with the already large stock exhaust without losing midrange. Amazing to see that with all these dynos that 2.0l has the torque curve of a v6 still. So what's the deal on the header? Will you be having a copy made or is DC finally going to release this out to the public? Any word on what the final pricing will be for this combo?

Mike
06 turbo
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Post by Brian »

Yes, very NICE...I remember a decade ago when we first put an Autorotor Supercharger on my 1994 Miata and were thrilled to get 150 horsepower at the wheels WITH 6 POUNDS OF BOOST....how times have changed!

No official word on the header yet...feel free to email be directly for updates. :wink:
Brian Goodwin
Good-Win Racing
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jaball77
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Cats?

Post by jaball77 »

I'm confused about cats... It's my understanding that the NC has a pre-cat attached to the header, and one in the "B" pipe... So does this setup eliminate both cats? Or will the mid-pipe have a high flow cat?

Also, what makes getting the stock header out difficult? 30hp is tempting. :D
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Post by Brian »

Yes, the NC has two cats. Our midpipe INCLUDES a higher flowing cat so that change to our midpipe does NOT alter the cat count.

But changing the header requires removal of the stock header cat. It is a tough install because all sorts of things are in the way on the NC. The brake lines are in the way, the heater core lines are in the way, and that cat you are trying to pull up is pretty thick...so it's a tight pull. Once you see the FACTORY HEADER without heat shield you understand immediately why you can't make much more power without changing the header....notice how the stock header, with primaries that are too short and not equal length, is pinched off as it enters the collector above the first cat. The factory primaries are almost pinched in half... :oops:
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Brian Goodwin
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NC+Will=Happiness
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Post by NC+Will=Happiness »

Reading all of this makes me all giddy like a school girl. Picture Homer Simpson when he does his "Oh boy! Oh boy! Oh boy!" dance and you will know how I feel about car mods! Those are some impressive gains without losing the midrange. I can't wait to bolt up the header and midpipe. Thanks for the update.
2006 MX-5 "Sport" 6-spd, Galaxy Grey, Black Interior
AEM CAI
RoadsterSport Exhaust
Eibach Anti-Roll kit
JIC FLT-A2 Coilovers some time in the next eternity!
miataman
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Post by miataman »

Thank you for the info Brian!
That's very interesting!

What kind of cat will the midpipe include?
I suppose that the CEL will stay off.

Did you get any a/f readings when you dynoed the car in the various states of tune?

A friend had a custom header and dual tip exhaust manufactured fitted with a metallic 350cpi cat on a 1.8 NC and the power on the dyno rose from 114 WHP to 128 WHP (he also had the AEM CAI fitted).
However his a/f mixtures rose up to 19:1 at certain RPMs.
After having a custom-made ECU chip installed, his a/f mixtures were down to normal and power was up to 134 WHP.

Have you looked into modifying the ECU any bit or installing an aftermarket ECU?

P.S. In Greece custom work is very common and quite effective too, due to the very high customs charges to import goods from the USA.
magnuson
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Post by magnuson »

I dyno tested the full MX-5 cup car exhaust. It has minimal muffling and no catalytic converter, so it should be even higher flowing than the setup brian tested. Since there was no cat I was easily able to test the air fuel ratio also. The a/f ratio stayed rich thoughout the powerband. So no worry of running to lean with any exhaust setup on this car. However, the car would probably make a bit MORE power if run a little more lean. An ECU reflash could probably give more power.
1992 & 2006 Miata
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Post by Brian »

Likewise, fuel/air ratios on mine were rich....with all the mods it idles at 14/1 and as soon as you hit the gas it got rich at 13/1 under load in the low RPMS and 12/1 in the upper rpms. Thus, as John notes above, we could certainly get even more power once we have the ability to lean out a bit.
Brian Goodwin
Good-Win Racing
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