Exo cars: DIY supercar slayer or enthusiast pipe dream?

[Vovchandr]

https://www.topspeed.com/cars/car-news/exo-cars-diy-supercar-slayer-or-enthusiast-pipe-dream-ar197048.html

 

Ever looked at a NA Mazda Miata and thought, "how do I make this lighter?"

 

Every car enthusiast at some point has wondered what driving a go-kart on the street is like. You might have also heard about a growing automotive niche subculture known as "Exo Cars". The concept is simple. Take donor car, remove the entire body and build a custom tube frame chassis on top. Throw away safety, aerodynamics, and basic livability for one thing: lightness.

 

The idea is that light cars go fast. Yet, is it that simple? Is this the magic solution that enthusiasts on a budget can consider? Will your Exo-Miata be able to keep up with a 911 GT3 because it’s a couple hundred pounds lighter? There are a lot of compromises and risks one must take to make this a reality.

 

The true first road-worthy example of an exo-car is the Caterham Seven, first produced in 1973. Developed from the 1950’s design of Lotus Seven, this kit car is still in production today. Colin Chapman, the founder of Lotus, had a distinct philosophy for his vehicles:
"Simplify. Then, add lightness."

Caterham idealized Lotus’s mantra and perfected it. Those lucky enough to experience one of these cars will understand its appeal. It is about as close as you can get to the experience of riding a motorcycle while still being in a car. A direct evolution of the Caterham is the Ariel Atom. This limited-production go-kart for the street has become the standard for modern exo-car. Yet, its $80,000 starting price and six to 12-month build time make it unobtainable for most.

 

So the question begs, what is an average enthusiast supposed to do if they want this experience?

 

BUILT OR BOUGHT?

 

The first question you have to ask yourself is what is the purpose of this car for you in the first place. Do you want the motorcycle experience without the associated danger? Do you plan to track it every weekend? You have too much time on your hands but still don’t have $50,000 lying around?

All legitimate questions that need answering. The fact is, 99% of people who build or buy an Exo Car actually want to ride a motorcycle. Yet, certain folks aren’t willing to take the risk or gain the skills necessary for riding.

 

So, a steel cage and seat belts quell certain demons but don’t solve everything. Anyway you look at it, there is going to have to be a compromise. It is a two-seat, open-wheel car with no storage or windows. Have you ever heard of rain? Yet, if your main concern is cost, a motorcycle is going to be the right answer almost every time. Yet, for those stubborn or scared, there are always alternatives.

EXOCET OR REGRET

 

Happen to have an NA Miata in the garage and it’s getting boring to drive? Willing to take away your already limited creature comforts for "performance?" Well, there is a solution. Welcome Exomotive Exocet.

This company sells complete Exo chassis and body panels to convert your Miata into a go-kart. Chassis start from $7,999 and range up to $8,999 with full roll cages. With some powder coating and freight shipping, expect several thousand more in cost. With a four-month lead time and average build time of over 100 hours, patience and a free schedule won’t be optional.

Not to mention, you’ll need special insurance and registration to even make the car legal to drive. As you can see costs can start to pile up. Will your local law enforcement also take notice of your go-kart on the street? No question.

Exomotive advertises selling over 500 kits of the Exocet. This means less than 0.1-percent of available NA or NB Miata produced have seen conversion. Considering the work and time associated, we understand why. But, what about if you don’t have a Miata at all?

DI-WHY?

Let’s say you have your own project car that’s sitting and has been for years. You want to spice it up and cutting the roof off is the only thing that will make you happy. If you take it to any custom automotive fabrication shop, expect quotes in the tens of thousands.

Do the work yourself? You’ll need to learn fabrication, welding, and design to start. That doesn’t even cover having the tools, space, and time to make it possible. Even for the savviest of garage warriors, a project like this is a multi-year adventure. Do you trust your welds in the case of an accident? Is it worth the effort and risk for you?

No matter what you do, we’ll be the first to tell you that your exo-Miata will not be faster than a stock 911. It will not feel like a Shelby Cobra. Still want the visceral experience of motorcycle, but need seat belts? This Caterham Super Seven on Bring-a-Trailer has a current bid of $17,777 with 12,000 miles. Even if you paid $30,000 for the Caterham, we guarantee money well spent which will save you countless headaches. For more on the Exo Car craze, check out Quickshift Cars Youtube channel.

 

[CarlB]

I haven't driven a Ariel but I suspect it doesn't drive as much like a go-cart as a Caterham. I raced go-carts. The handling is heavily influenced because of the solid axle. You drive a go-carts of the rear tire. You drive a Caterham of the rear tire. Generally independent rear suspension cars are driven off the front wheel. BMW had a driving experience I got to go to. They had pro drivers as instructors. My instructor ask me if I had raced go-carts because I drove the car off the rear tire. Then he tried to correct my driving.

[Croc]

Calling our resident Exomotive expert to the thread @xcarguy who is building one.  

 

I have driven an Ariel on track.  Its got a 60/40 rear bias and you notice it as you try to turn the nose in.  Your weight transfer is critical to get weight on the nose for a crisp turn in.  It needs a heavier hand than a Caterham to get the weight on the wheels where you need it.   Fantastic rear end grip out of corners.  Twitchy for turn in to corners though - reminds me of an old 911.  You know you have a ton of weight out back just waiting to pass you if you misjudge.  Far more accomplished than an old 911 though.

 

The Ariel is bigger and you feel that size.  The Caterham is tighter shape and so it is easier to place on the road/track.   

 

I would not say you drive a Caterham off the rear wheels?  You do a combo of weight transfer with brakes and throttle - its a more balanced chassis than an Ariel and more nimble for driving adjustments as a result. I want the center of motion to be around the driver and not around the front wheels or the rear wheels exclusively.  If the front is not cooperating because it is not up to the task then you use the rear (via throttle) to bring the car around - e.g. a 1965 Mustang GT350 requires this.  

 

[xcarguy]

9 hours ago, Croc said:

Calling our resident Exomotive expert to the thread @xcarguy who is building one.  

 

 

 

Not an expert on the Exocet by a long shot. If you remember, the reason I started the build was to bond with my kids. And that, we’ve done. Been a great experience this far.

[NeoBear]

Years ago I drove my Friends Atom at a cart track and immediately went looking for something similar. An Atom almost demands you know what you are doing at all times, it was more scary then fun to me. I feel so much more comfortable in my Seven.