mx5cartalk.com

Posted: **Mon Aug 06, 2007 11:19 pm**

I don't think they can improve on the factory system at this stage.

Posted: **Tue Aug 07, 2007 9:23 am**

Brian Goodwin is just about to release his new header system.
It's been in development for the last 12 months extracting the last kW or HP out of the design.
Problem is that it removes the first cat that's located straight after the header, so to comply you may need a bigger cat where the second one is located.

Have a look here. http://www.good-win-racing.com/

Posted: **Tue Aug 07, 2007 3:49 pm**

Any NC owners thought about the AEM air intake?

link here

Posted: **Tue Aug 07, 2007 3:56 pm**

$A300

Nope.

Posted: **Tue Aug 07, 2007 4:33 pm**

JBT wrote:$A300 Nope.

$300 including delivery from the US isnt bad considering if its dyno proven and bolt on.

Theres also a little thing called a group buy you could knock off some $$$.

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.

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. NICEâ€¦158.9 hp and 137 Ft/Lbs!! This is the Spec Miata Race Header with our midpipe and exhaust and the AEM intake. Note that the race header does NOT have hookups for O2 sensors. You must splice and extend the O2 sensor wires. However, our midpipe includes TWO O2 sensor bungs, one before and after the catalytic converter to make it easy to relocate the sensors so you avoid a code. Nice BIG gain from the header but since the header is a pretty difficult install (getting factory header/cat combo removed is tough), I expect that most folks will be happy to get the gains of the RS muffler + AEM intake + midpipe and leave the factory header alone. Also, our Midpipe uses a massive 18 inch long resonator to keep sound the same despite the gain in flow over the stock unit... but if you then also add the race header it by itself adds a lot of sound. If you like old Italian Fiats and Alfas then you will love the sound of this car with the header...those with more delicate sensibilities should forget the header. Note the interesting comparison with the Grassroots MotorSports project NC Spec Miata, we started with the exact same baseline results and finished 2 hp and 2 ft/lbs stronger....which means we found all the gains of the full race system without the full race system noise!

Brian Goodwin (Roadster Sport):
Header + Midpipe + Muffler = 25+ WHP
Price: $1000 -/+

Racing Beat/AEM/MazdaSpeed Intake = 7+/- WHP
Price: $250+

22rwkw gain for $1400 AUD on a naturally aspirated application is exceptional bang for buck mods.

Posted: **Tue Aug 07, 2007 5:59 pm**

22 Kilowatts from an intake & extractors???............give me a break!!! :roll:

Posted: **Tue Aug 07, 2007 6:07 pm**

If you believe that I have a bridge in Sydney I can sell you really cheap :lol:

Posted: **Tue Aug 07, 2007 6:25 pm**

AJ wrote:22 Kilowatts from an intake & extractors???............give me a break!!!

25 if you add a sticker or two on the fender!

Posted: **Tue Aug 07, 2007 6:35 pm**

Craig wrote:
AJ wrote:22 Kilowatts from an intake & extractors???............give me a break!!!

25 if you add a sticker or two on the fender!

i don't have "fenders" on my car

Posted: **Tue Aug 07, 2007 6:39 pm**

Nah just those \"metro poofy\" pumped gaurds to make the NC look tougher eh! :lol:

Posted: **Tue Aug 07, 2007 6:51 pm**

AJ wrote:22 Kilowatts from an intake & extractors???............give me a break!!!

Intake, extractors, midepipe with HFC, and muffler.

http://www.good-win-racing.com/mazda-ta ... .php?t=438

Intially i thought the same, no way in the world those kind of numbers cound be gained with so little modification on a naturally aspirated application. I guess when mania replicated the above on a NC locally minus the headers and got similar numbers my opinion altered.

Posted: **Tue Aug 07, 2007 8:29 pm**

sorry mate, it'd take more than a fallible rolling dyno result to convince me that doing a couple of VERY minor modifications will produce that sort of power gain in ANY engine, let alone a modern electronically controlled engine, ask anyone who has built a race car how hard it is to gain precious power increases, just changing how it sucks & blows will do bugger all unless you do something to the in between bit, i'm not saying you won't get any gain, of course you will, as long as the original exhaust & intake are poorly designed, & i honestly don't think that is the case on the NC, the MZR 2 litre engine is free revving & boisterous, i've never noticed it being restricted in any way, & i've particularly noticed how hard it wants to go since ours hit 10k, it has developed a nice mellow exhaust note that is fairly \"raspy\" up to about 5k on the tach, after that it actually howls right 'round to 7200 without hesitation, in every gear, just because it'll make more noise with a open filter & a straight through muffler, doesn't mean its going any better, it might SOUND like it does, but that's about all..............i like stealth, blow the bastards away without 'em knowing what's hit 'em is my policy, & keep Mr Plod from taking any notice of me :mrgreen:

i really don't get this love affair everybody has with rolling dynos, back when i was playing with 6's & V8's they were only EVER used for tuning purposes....................you don't think the guy that owns the dyno isn't rubbing his hands together every time 25 MX5's at 50 bucks a hit come through his shop on a saturday morning???...............money for jam, specially if he can sell you some bits & then \"show\" you the gains you've made on a machine he sets up??.........i might buy a dyno & make some money on weekends :lol:

Posted: **Tue Aug 07, 2007 9:07 pm**

AJ, it's been done localy as well though. Mania wouldn't fiddle with the dyno between runs just to falsify a figure.

Just because your car feels really strong and revs out beautifully, doesn't mean it's using it's full potential. The NA6 is a beautifully revving engine and good gains can be made to that through mods.

No, sound does not = power, but the manufacturer has to keep withing limits for sound and emissions. No doubt these mods would blow those restrictions out of the water but it may (and i'd say probably does) release some very good potential.

Posted: **Tue Aug 07, 2007 10:07 pm**

mazlot wrote:If you believe that I have a bridge in Sydney I can sell you really cheap

How cheap?

Posted: **Wed Aug 08, 2007 7:52 am**

For you JBT, $1400, and I will throw in the 22 kW for free :lol:

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