ThatKid New Reader
10/20/08 12:28 a.m.

I've been really turned onto the idea of a locost lately. I doubt this will happen anytime soon (or at all) considering I have no job and I'm a high school student who lives at home. Keep in ind I've only been looking into this for the past few days, so I might not have everything straight.

My main concern is keeping this cheap, like, as cheap as possible while not being a deathtrap. I know Cheap and 'built from the ground up sports car' don't quite go together, but just hang with me on that if you can.

I'm not sure what I would want to use as a power plant, Bike powered would be cool, but it would also be a big PITA as far as reliability, power (Or rather tourque) goes, Seems like it would be on the pricey side too. I would really like to do a mid/rear engined dealio using a a FWD engine/trans, but I'm not sure if I would be up to all of the extra hassle (that's probably not the best word to say when It comes to talking about building a locost though, ha) So that pretty much just leaves me with the same-old front engined, rear-drive donor, probably a Miata. But but what about a small pickup like a Ranger, Nissan Hardbody or Toyota pickup? The earlier ones are wicked cheap up here since they're all rusted out and pretty much un-driveable. They aren't as awe inspiring power wise, but they reliable as berkeley and cheap as chips. Not to mention I' not too concerned about having something that's fast straight in a line versus in the twisties. So that seems like a solid plan unless I'm missing something? I like to keep things simple as well, so I would probably just use a solid rear axle, which could probably be had out of the truck.

Suspension has me stumped though, Not really sure what I would do, I could build something up, but that seems out of my skill range (then again this pretty much this whole thing does ) So it seems like A Miata would be a perfect candidate for this, I would probably have a to buy an entire car just to get the suspension, and like I mentioned I want this to be cheap, so that doesn't quite work out in my favor.

And as far as a chassis goes, I would want to build my own, once again for the cheap factor. I haven't looked much into chassis design/fabrication yet so any pointers or tips would be great on this.

Alright, that's all I've got for now, I'll be back with more though.

SVreX SuperDork
10/20/08 5:51 a.m.

Bike motors are fun, but no longer allowed by the SCCA. Why put this kind of effort into a car that can't compete?

Your Miata idea is better than you think. The cheapest and easiest way to build a locost is likely to be using a Miata for the chassis. The Miata has a front subframe and a rear subframe. If they are both removed from the body, it would be very easy to simply put in a few subframe connectors and Voila"- instant Locost chassis, with great performance out of the box.

Add turbo, megasquirt, and you've got a contender.

Talk to Mr. Joshua for more details.

SVreX SuperDork
10/20/08 5:55 a.m.

Keeping it cheap is good, but keeping it safe is paramount, and keeping it simple (especially for your first project) is the best way to have any chance of the thing getting finished in the first place.

Find a wrecked Miata with a damaged interior from it's leaky roof as a starting point, and you should be able to keep it cheap as well.

Dr. Hess
Dr. Hess SuperDork
10/20/08 8:35 a.m.

The final cost of your Locost depends on how good of a scrounger you are and what your "theme" is. For example, if you want super cheap, then finding scrap 1" square tubing and bike coilovers or some of the other inexpensive coilover instead of aluminum double adjustable Konis.

The Book is mostly inspirational, but a good read. I suggest starting there.

Hasbro HalfDork
10/20/08 9:11 a.m.

Chebbie_SB Reader
10/20/08 9:40 a.m.

Look for Keith Tanners book "How to build a cheap sports car" roughly thereabouts, google his name, he posts here quite often.....


Keith SuperDork
10/20/08 9:50 a.m.

Like right now! :)

First question: are you building a Locost, or are you building a locost? For some, "locost" has come to mean any home-built car. SVreX's idea of joining two Miata subframes with a tube frame would be an example of such. It'll have little or nothing in common with a Lotus Seven and thus won't be a Locost, but it might be locost. Get the distinction? Once you start to wander off on your own, you'll find there are all sorts of interesting side roads to head down and the difficulty of your build increases dramatically as you have to engineer your own solutions to problems instead of following those that have gone before.

If you're thinking Locost, it's not that big a deal to adapt the frame to accept the rear Miata subframe. The front of the chassis, however, is quite a bit narrower and you're better off building your own control arms. That's not a big deal compared to building the rest of the frame really.

The truck parts aren't a bad idea, but check your weights and dimensions. Truck stuff tends to be big and heavy, not necessarily a good setup for a light car. There's a reason that people use the "same old" donors for these things - they work. If you find a decent Miata, you'll be able to part it out and bring your total cost down to free without too much trouble. I've always considered a Miata donor to be free for this reason.

While a few people have built sub $2000 Locosts, the typical cost of completion is around $6000-8000. Just FYI.

Chebbie_SB Reader
10/20/08 9:59 a.m.

Thanks Keith! (hope I didn't butcher the title of your book too badly) very good points on engine height 'cuz you wanna keep it under the hood, and keep the car as low as possible. So "That Kid" look at what has been done and decide if that is what you are thinking or more of a one off mid-engine approach.


Keith SuperDork
10/20/08 10:51 a.m.

You nailed the title, good job :)

SVreX SuperDork
10/20/08 12:24 p.m.

Thanks, Keith, for correcting my "L". You're right.

mainlandboy New Reader
10/20/08 2:55 p.m.

I don't post here too much, but as someone who has completed a Locost, I thoght I'd chime in.

Based on your budget and building experience, I would highly recommend you base your first build around the conventional Locost design, rather than the M/R setup. You will have a much easier time completing it, given the amount of resources available on the net, discussing how to handle all the different challanges with building it. If you haven't checked it out already, download a copy of the free chassis drawings here:

With the conventional Locost design, you will have a much easier time finding parts that you can't or don't want to make (specifically, the nosecone). I used a 1982 Toyota Corolla as a donor, which I picked up for $200. The most expensive parts of my build were the coilovers and the wheels and tires i used. My total build cost ended up being $7500 CDN.

Do you have a place where you can build it? Make sure that you have that in place before spending the first dollar. I ended up building mine in my parents dusty chicken barn. Not the greatest conditions, but it's what I had available.

Also, be sure that you are willing to commit to the time that it will take to complete it. It took me just over 3 years, working on it about 10 hours a week. If you don't have a welder yet, you will need to buy one. I used a Hobart model with a gas setup that runs on 110 V, and it worked great. The total setup (welder, gas bottle, helmet, gloves, etc) was just under $1000 CDN (new).

As a donor, the Miata is about as good as you can get, but is price and ease of build is an issue (as it was for me), you may want to find a solid rear axle decent running RWD donor. Early 80's Corolla's fit this category (I'm biased though).

Hope this helps, Mark

96DXCivic Reader
10/20/08 4:28 p.m.

Why not design your own pushrod suspension? It will be more then likely cheaper then buying a Miata to tear apart.

John Brown
John Brown SuperDork
10/20/08 4:47 p.m.

I strongly suggest not designing stuff from scratch.

Build a "+" frame around front and rear second gen Mazda RX7 5 bolt suspension crossmembers. Use common design practices when approaching the box framing and scale it length to width. The RX7 suspension will open a range of wheels up beyond belief. You can then add Rotary/4 cylinder/350 Chevrolet whatever to the mix for grunt.

Nose cones and scuttles can be bought and modified if needed for relatively cheap, don't bother building your own.

96DXCivic Reader
10/20/08 4:51 p.m.

I have access to all kinds of CAD/ analysis software that will allow me to design my own vehicle like I am doing right now. But if you don't have access to stuff like that, you should go w/ the other suggestions.

jamscal HalfDork
10/20/08 4:59 p.m.

Here's the best/cheapest way, IMO:

Chevy S-10 Donor 2wd with V-6 and 5 speed.

The stick rear on a 2WD fits a book frame nicely, and is upgradeable.

The 60* V-6 was put into EVERYTHING in many various configs. NO lack of parts or knowledge.

T-5 Trans is a known quantity.

There is info on using S-10 spindles on the locostusa site.

I would probably go with Mustang II spindles and source them and adj. upper A-arms from Speedway, leaving only the lowers to be fabbed. You can buy a Mustang II spindle/brake pkg with a Chevy Bolt pattern.

Some people use Fiero and Chevette Front spindles as well.

There are also a bunch of cheap suspension bits at Speedway.

The Brunton Superstalker (awesome) to my knowledge bases their kits/cars on the above.

I've built about 5 frames so far and will probably start developing the next one with the above mentioned components in mind.

Good luck,


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