Is It Still A Girl's Car With a Corvette Engine?

I love Miatas.  They're fantastic cars. I mean, they won't haul furniture or run 11 seconds quarter miles stock, but if you want a light, 2-seat roadster that requires no more maintenance than a Civic - they're hard to beat.  Just enough power to be fun, chassis balanced on a knife's edge, a top that goes down with one hand in about 10 seconds, killer gearshift, pedals placed perfectly for heel-and-toe downshifts, an aftermarket as wide as the sea.  But since the first MX-5 rolled onto our shores in late 1989, it's had a perceived stigma of being a "girl's car."

I'm not sure why.  It's basically a Lotus Elan updated with modern electronics, fuel injection, and Japanese reliability.  And the Elan was basically a race car with license plates.  So quite why the Miata got a bum rap as a hairdresser's special, I don't understand.  Probably something about American insecurities at small cars, the friendly non-threatening nature of the MX-5, or maybe our fascination with engines that are far too large, stuffed in cars far too small.  (What else could explain the axle-hopping AMC Gremlin X?)

So here's a question for you: if you stuffed a GM LSx block (Gen III/IV Small Block V8) into a Miata, is it still a girly car?  Because as improbable as that sounds, uhh - there's a conversion kit for it, and it's actually been happening for quite a while now.

Flyin' Miat's Project "Elvis" - an LS3-powered Mazdaspeed NB.  OMG.

An LSx-swap gives you lots of choices for how wild of a Miata you want.  Want to keep it cheap but have some V8 rumble and still enough torque to light up 3rd gear?  An older LS1 (5.7L all-aluminum 16v V8 from the C5 Corvette, 03-04 GTO, Camaro Z28, etc) puts down 350bhp and torque, and those motors aren't exactly expensive these days.  A 6.0L LS2 from an early C6 or late 1st gen CTS-V offers an even 400/400.  Theoretically, an LSA (CTS-V, Camaro ZL-1) or LS9 (Corvette ZR-1) would fit, but frankly you could supercharged an LS2 for a lot cheaper than a crate LS9.  How about the LS7?  The all-aluminum 427ci dry-sumped V8 from the Z06, that makes 505bhp and redlines at 7,000rpm (which, by the way, is higher than a stock Miata 4cyl)?  That'd work too.

I wish there was a bigger picture of this.

How do they make this happen?  A very comprehensive, well-developed swap kit.  As you'd imagine, there's more to it than just "1) Remove 4cyl.  2) Insert V8."  There's a tubular engine subframe that fits the LS block (which is 10lbs lighter than the stock subframe!), frame rail reinforcements with transmission mount slots; they even have a  choice of two engine locations - one that mounts the engine further towards the firewall for better weight distribution and mounting the shifter in the stock location, and one that's 2" further forward that doesn't require modification to the transmission tunnel.  FM uses the same Tremec T56 6-speed manual in their conversion as GM uses in the Corvette, GTO, Z28, CTS-V, etc - so it's more than up to the task.

You also have a choice between a Getrag rear differential or a Ford 8.8", the latter preferrable for people that will be drag-racing.  It's heavier but more robust.  You can use a stock F-Body (Camaro) oil pan, or FM offers an aluminum baffled oil pan that prevents oil starvation under hard cornering for extra cost.  They offer basically everything you need to make an LS-powered Miata in your garage, actually: a bolt-on exhaust system that fits, radiator fan shrouds to cool the motor, a custom front sway bar that fits around the new subframe and the crank pulley, a power-steering setup (that would probably be a must-have), even longer front springs with a higher spring rate to compensate for the extra weight.

About that extra weight: FM claims that an LS-swapped Miata is only about 200lbs heavier than a normal Miata, and 1/3 of the added weight is over the rear end (due to the beefy V8-capable differential.)  A Miata with an aftermarket turbo setup is approximately the same weight and distribution as an LS-swapped one, but obviously doesn't offer nearly the same power and torque.  Unlike the Monster Miata swap (which mounts a Ford 302ci Windsor V8 up front) that pretty much trashes the weight distribution, having a light LS block shoved all the way to the firewall has a negligible impact on weight distribution.  Plus, if it starts to understeer, you have about 3 times as much torque under your foot as a normal Miata - just hit the gas!

How much does all this cost?  The full LSx swap kit, in a box, retails for $3,805, but obviously doesn't include an engine, transmission, etc - it's just the hardware to make it fit.  At the top end of all the craziness, FM offers a "we do it for you" LS3 Turnkey kit, where you bring them a 1st or 2nd generation Miata and $29,940, and they give you back a Miata with a 436bhp Corvette LS3, 6-speed transmission, and enough sleeper factor to scare all small children in a 1-mile radius.  Delicious.  It has perhaps the highest cognitive dissonance factor of any engine swap out there.  I mean, how confusing is THIS video?

httpvh://www.youtube.com/watch?v=1p-EvqjI1c0

Of course, stuffing an LS-block into a Miata is just the start.  As you're probably aware, the aftermarket possibilities of an LS-block are immense.  Bore and stroke it, turbocharge it, supercharge it, feed it off the bottle, or just do an N/A build with ported heads (or LS6 heads if it's an LS1) and a strong street cam which will drastically increase power output.  Would it be possible to build a 900-horsepower twin-turbocharged LS3 Miata?  Entirely.  Just depends on how deep your pockets are, and exactly how insane you are.

httpvh://www.youtube.com/watch?v=OB4ZkhirtUI

Now, the question is - when a Miata sounds like this as it rockets past you... is it still a chick car?  I'd say it wasn't to begin with, but this should be food for thought for Miata haters.

If you're interested in turning your docile Miata into a tire-smoking monster, you can find Flyin' Miata's website here.  All the pictures of the blue NB Miata (Project Elvis) are from FM's website.  And yes, it originally had an LS1 and now has an LS3.  Do want.