What happens when you take the stiffest and most refined Miata->ke1185 ever built, and then have Flyin’ Miata cram a fire-breathing small block V-8 under the hood? You get one of the best cars I have ever driven. Period.

This is Atomic Betty and she has stolen my heart.

With more than 400 horsepower and an equal measure of torque, Atomic Betty takes the power and thrust of a Corvette->ke1280, and cuts a few hundred pounds. The results are staggering to say the least. Despite the insertion of the large engine, very little of Betty has been altered, and from the exterior she looks like a stock NC Miata to 99-percent of onlookers. If you prefer the idea of a “sleeper,” Betty is about the best you can get.

Best of all, the weight balance has barely been changed and overall weight gain from the new engine is less than putting a full-size male in the passenger seat. That means that same handling and crispness of the Miata remains, there just happens to be almost three-times as much power at the call of your right foot.

Hell. Yes.

Continue to read more about Flyin’ Miata’s V-8 powered NC Miata Atomic Betty.

2009 Mazda MX-5 Miata "Atomic Betty" by Flyin' Miata - Driven

Specifications
  • Make: Array
  • Model: 2009 Mazda MX-5 Miata "Atomic Betty" by Flyin' Miata - Driven
  • Engine/Motor: V8
  • Horsepower: 430
  • Torque: 400
  • Transmission: T56 6-Speed Manual
  • [do not use] Vehicle Model: Array
Pros
Cons

Exterior

Atomic Betty may be one of the fastest Miatas money can buy, but you would never know it from the outside. Aside from the large exhaust, subtle fender flares and the hood pins, Betty looks like a completely stock, third-generation PRHT Miata. Well, if you ignore the giant “Flyin’ Miata V8” sticker across the windshield anyways. The nose does feature some black inlets where the fog lights used to be that feed cool air to the brakes, but that is the most noticeable modification.

One of the biggest reasons, Betty looks stock is the fact that FM used Mazda parts whenever possible for modifications. Those black fender flares are the same ones used on Mazda’s Super20 concept car.

The point is, that if you ordered a recreation of Atomic Betty for yourself, the rumbling exhaust would be the only real clue that you had anything but a 2.0-liter sitting underneath the hood of your tiny roadster. It’s phenomenal.

Interior

The interior of Atomic Betty follows the same philosophy as the exterior. FM has only changed what was absolutely necessary, and left everything else alone. There are new gauges and the shift knob has been replaced with a nicely milled aluminum one. Bolted directly in front of the shifter is a small placard showing the cars new shift pattern. There is no roll bar in Betty; there is no useful unit that fits below the power hardtop.

The gauges themselves are a set of aftermarket Dakota Digital units that have been used to offset a previous issue encountered when Betty was first built. It seemed that the GM ECU needed to run the engine of Betty didn’t cooperate well with the stock gauges. The issue has since been resolved and all V-8 NCs going forward will feature the stock gauges, or the FM custom gauges.

This is good news, as the gauges installed in Betty are a bit too garish and aftermarket for a car of this caliber.

As a Grand Touring model, Betty has leather seats, leather trim on the doors and the upgraded stereo with SiriusXM satellite radio. It is every bit as luxurious as the decked out 2014 Miata I tested just a few weeks ago.

Drivetrain

Obviously, when you are talking about a V-8-powered Miata, the magic happens in the engine bay. Betty was the main test car for FM and it features the company's full V-8 turnkey swap. This swap starts with a factory LS3 crate engine from GM with the 430-horsepower cam. This is basically the same engine you get in the 2014 Camaro SS. The stock Miata transmission is dropped in favor of a built T56 six-speed manual that uses a custom shift lever. The clutch and flywheel have been plucked from the parts bin of the LS7.

FM continues to raid the high-end parts buckets at GM to source the intake. The intake system itself is the cold-air unit from the LS7, and the air filter is the same one GM put on the LS9 motor that powers the ZR1 Corvette. Cooling is provided by a custom crossflow radiator and the exhaust is carried away via a custom exhaust system with a lifetime warranty.

Making sure all that power hits the road, Flyin Miata installs a Ford 8.8 rear end with a clutch pack LSD. Making sure the transmission and rear end communicate effectively, Betty has a new steel driveshaft. If you want your own V-8 NC, Flyin’ Miata does offer upgrades to aluminum or carbon fiber.

Actually fitting the engine does not take much effort. Thanks to the NC-generations larger size, the V-8 fits with basically zero modifications. There is one small piece of metal that need to be rolled slightly. There is no alteration to the transmission tunnel at all.

After all is said and done, you are looking at incredible power and speed. GM claims the LS3 is good for 430 horsepower, but Betty has been dyno tested to 410 at the wheels. Considering the altitude, a sea level number at the crank of 450 or more is pretty feasible. The 0-to-60 run will pass in about 3.8 seconds, and while no official top speed has been tested, north of 175 mph should be easily attained.

Brakes and Suspension

When you are exponentially increasing the power and velocity of your car, making sure it can stop and actually make it around a few bends is a pretty important consideration.

Starting with the suspension, Betty has been fitted with the full FM Stage 2 suspension kit. This is the same thing found under Nancy, the supercharged Targa car. That means Tokico HTS shocks, FM springs and FM sway bars. Just as in the Targa car, the ride is very compliant without being too loose. It works well on the track and off.

Bringing all this American small block fury to a stop is the FM NC Little Big Brake Kit. The kits comes with stainless braided brake lines, slotted rear rotors, Wilwood Dynapro front calipers and Wilwood Powerlite rear rotors. The rear rotors are still compatible with the stock handbrake, and a set of BP-10 pads comes for all corners. In the normal brake kit you would reuse the front rotors, but Betty has a slotted set up front.

Wheels are a set of 17x9 TR Motorsport C3Ms with Dunlop Direzza ZII rubber. That means 255s under every corner for maximum lateral grip.

Pricing

Price is a very fluid thing when it comes to a full engine swap like Betty. If you are not the type who wants to take the time and energy to spin wrenches and get dirty making your own V-8 Frankenmazda, Flyin’ Miata offers turnkey conversions. Essentially, you drop off your Miata, come back in about 10 to 12 weeks and voilà. You turn the ignition on and drive away. The price for this service is a Lincoln under $43,000. That price does not include any extras or upgrades like the carbon-fiber drive shafts or hotter engine cams. You also still need a donor Miata to begin with as well. You can find nice used NCs for $15k and under, so total you are looking at around $58,000 for a professionally built replica of Atomic Betty.

If you did some searching, you might realize that is the same price as a base Corvette Convertible. That might seem like a hard decision for some, but I can tell you that GM wouldn’t be seeing any money from me in this situation. If you already own a Miata but want more speed, there is no contest here.

Driving Impressions

While doing this job, occasionally you come across a car that alters your perception of things. The GT-R taught me just how fast and violently a car could accelerate, the CTS-V Wagon taught me the meaning of “practical power” and the Lamborghini Gallardo let me know just how good an Italian can sound. All of those cars pale in comparison to Atomic Betty.

This little Miata combines all things good in the world into one succinct package. It has the V-8 rumble of a classic muscle car, the steering feel of a proper sports car and the inconspicuous exterior look of a humble Miata. The suspension is supple enough for hours of highway cruising, and thanks to the power hardtop, it is as watertight and serene inside as any coupe. When you feel like being a hooligan, drop the top, stand on the loud pedal and laugh as you lay rubber from the Grand Canyon to the Mississippi River. This car is literally all things to all people. Hell, if you need practicality, just buy a hitch and it will happily tow a camper. The damned thing even manages to get around 30 mpg in steady state highway cruising.

And man is it fast. It won’t launch as violently as the GT-R thanks to the laws of physics and simple traction, but once it moves it never stops. Hand on heart, nothing I have been in feels as fast as this Miata. It takes only seconds for triple digits to appear on the speedometer. If Bill had told me he managed a 200 mph blast on his way to work, I would believe him. If you start from about 30 mph, nothing I have driven can reach 100 as fast as this car.

Atomic Betty is Dr. Jekyll and Mr. Hyde without all the murdering and insanity. Serene and comfortable one minute, destroying supercars and lap records the next. All with a power hardtop and leather seats.

You can buy a brand new top-spec Miata and have it converted for less than the price of the cheapest 911 Convertible. And when all is said and done you have a car with close to 100 more horsepower, better fuel economy, and it attracts less attention.

I have never had the keys to anything as well rounded and wonderful to drive as Atomic Betty. For lack of a better word, this car is essentially perfect.

The Reason to go with the Small Block

One of the biggest concerns and fears about a car like this revolves around what to do if/when anything breaks. Well guess what, you just drive it to the dealer. Because Flyin' Miata uses crate engines direct from GM, they have a two year warranty. Even if the warranty runs out, you still have a car powered by a General Motors small block. Any dealer can order parts for you. Thanks to general ubiquitousness of the small block, you can also find parts at most parts stores, and even at junkyards if you felt so inclined. Of course, since GM has been making the small block V-8 for decades and decades, they are extremely reliable so you are not likely to have any issues to begin with.

Competitors

Chevrolet Corvette Stingray Convertible Z51

Considering my thoughts on how it drives compared to the price, there are really no competitors to this car. The closest thing might be the Corvette Convertible with the Z51 performance package. With a dry sump oil system, electronic LSD and better brakes and suspension hardware, the Z51 equipped Vette makes for a fairly substantial competitor to Atomic Betty.

Of course considering the Corvette Convertible has a curb weight of 3,362 pounds, the Miata holds a 500 pound weight advantage over America’s Sports Car. It isn’t hard to see which car would likely come out on top in a performance challenge when they both sport similar power ratings. If you go by power to weight ratios, Atomic Betty is more closely matched with a Porsche 911 Turbo.

Let that sink in for a minute.

Porsche 911 Turbo Cabriolet

Since Atomic Betty has such a high level of horsepower and performance in such a tiny package, it is hitting way over its league. The humble GM engine has propelled Japan’s little roadster into the territory previously occupied by names like Lamborghini. As we already discussed on a pure power to weight standpoint the 911 Turbo lines up almost perfectly.

Thanks to the fancy all-wheel drive system on the Porsche, it will beat the Miata to 60 mph, but beyond that point is anybody’s guess. Due to its more aerodynamic shape, the Porsche will also very likely hit a higher top speed, but a few modifications to the body of the Miata could change that fairly easily.

Of course considering you could buy nearly three V-8 Miatas for the $151,000 base price of a 911 Turbo, there still isn’t much of a competition here.

Conclusion

When your only real complaint about a car is, “I don’t like the gauges” you can be sure the machine is solid. Atomic Betty feels as stiff as a tank, has more speed and power than I can even begin to think about what to do with, and it is all wrapped up in that same smiling shell and incredible handling that the Miata is known for.

More than the speed Atomic Betty shows incredible build quality and attention to detail. This may be a car that was essentially built in a shed by a dozen guys in the desert, but you would never know it. Open the hood and compare it to anything coming out of the factory at GM, or even Audi for that matter. Every wire, plug and hose is carefully routed and positioned. You even get a personalized build plate, just like the one you find on the engine of a GT-R.

Of all the cars I have ever driven, none have made me happier or been more enjoyable than Atomic Betty. If you are looking for the best combination of speed, comfort, quality and understated looks, give Flyin’ Miata a call.

If you buy anything else, you are wrong.