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modernbeat HalfDork
4/20/09 1:07 p.m.

A pal of mine has stuffed Miata front and rear subframes into a Honda S600. Motive power is a 13B. Plan is to compete in SCCA Solo X-Prepared.

MiaTurbo New Reader
4/20/09 1:27 p.m.
Keith wrote: Check this out - I put this link in my previous post, but it might have been lost. Mark River is doing just that. http://rivera.fotomojo.us/g/2ndbuild ...

Do you know what size tubing he used? it looks like 2x2". I've e-mailed him in the past, but got bounce back messages...

i was thinking about doing a similar set up as far as engine set back/body/etc, but was thinking instead of using Miata sub-frames bolted to a frame, to make the Miata suspension pick-up points right onto the frame. it would end up lighter, and less mounting points which could lead to points of faliure.

I never liked the styling of the 'lotus 7' replicas, so always wanted a full fendered body on what ever I end up building Like Mark is designing.

Keith SuperDork
4/20/09 2:05 p.m.

I've asked Mark to chime in here.

On my MGB, I was originally planning on mounting Miata subframes. But like you, I figured it made just as much sense to make frame rails with the Miata pickup points. So that's what I've done.

Kreb, love the 544. Especially the juxtaposition of big dubs and a window net

4/20/09 2:44 p.m.

Thanks for the heads up, Keith.

It's true, I plan to offer a low-entry-cost, Miata-based single donor track car kit. I currently have a rolling chassis with the same turbocharged engine from my Locost project, which some of you may know met an early demise at Mid-Ohio with a brake failure a couple years ago. I recently disassebled another low mileage donor, and have been working on 3D modeling of all the little bits and pieces I'd like to reuse from the donor to keep the kit cost as low as possible. I've been through various body concepts since I started, but many of them are too cost prohibitive to fall in line with the mantra of the whole project. To save weight and get the cost way down, you may end up seeing a very spartan car with some creatively shaped thin aluminum sheet draped over the chassis.

I work as a manufacturing engineer, and am fortunate enough to work for a company that will be able to support the demand once the kit goes into production.

In a nutshell, the car will retain both front and rear subframes (I have considered eliminating them, but I want the disassembly and assembly to be as straightforward as possible), will have a steel tubular chassis with enough room to accomodate an LS1, will have a wheelbase around 6" longer than the Miata, the engine is moved back about 10 inches, and the overall height will be under 40". Key components retained from the donor (besides the drivetrain, subframes, suspension and brakes) will be the steering column, radiator and fans, pedal box (maybe), fuel pump and level sender, filler neck, instrument cluster, e-brake, and a few other odds and ends that will add up to keep the cost low. Target weight is just under 1500lbs. Weight distribution should come in around 45F/55R. The miata shocks will go in the trash, and adj. coilover shocks will be pushrod-actuated at each corner.

I'm still a few months away from having a working prototype, but progress is being made every day.

Glad to see there's some interest!

Mark Rivera

Xceler8x Dork
4/20/09 3:17 p.m.


Do you have a mailing list? I'd like to eyeball this thing once you're done.

dyintorace Dork
4/20/09 3:18 p.m.
mxseven wrote: ...will have a steel tubular chassis with enough room to accommodate an LS1...

Mark - thanks for the additional information. It sounds like a neat idea, especially the quoted part above!

Sultan New Reader
4/20/09 4:19 p.m.

Mark, Please keep us updated! And I would love to be on a email list. RS

mxseven New Reader
4/20/09 5:03 p.m.

If you'd like to be on a mailing list for updates and such, send an email to pacomotorsports AT gmail DOT com, and request to be added to the email list for the FX-5 project. I've been working on engine related stuff lately, but I'll get the camera out and do a chassis update soon.

Thanks! Mark Rivera

Rangeball Reader
4/20/09 6:22 p.m.

Emailed to be on the email list.


Xceler8x Dork
4/21/09 8:49 a.m.
mxseven wrote: If you'd like to be on a mailing list for updates and such, send an email to pacomotorsports AT gmail DOT com, and request to be added to the email list for the FX-5 project. I've been working on engine related stuff lately, but I'll get the camera out and do a chassis update soon. Thanks! Mark Rivera

Done! Thanks!

MiaTurbo New Reader
4/22/09 9:55 p.m.

Ok, I know it's not a locust, but here is a kit that uses Miata subframes: http://www.sportscars.net.nz/

Keith SuperDork
4/23/09 12:20 a.m.

That's the MG replica I mentioned earlier. An email correspondent of mine runs one in the Targa NZ, which is cool on a bunch of levels.

RandyS Reader
9/3/10 8:56 a.m.

Sorry to drag up an old thread but I've been thinking about this a lot lately.

Back in the early 90's there was an MGA kit car that used Miata control arms and a Toyota 4AGE engine. It never sold (only the prototype was made) because it was made with expensive composits instead of fiberglass ($22k kit in 1991 dollars), required a MGA donor, and was ahead of it's time since a real MGA was only $1500-3500 then.

Fast forward 20 years and good MGAs are $20k and good running Miata's are $800. This is the car body that should be dropped on the Miata backbone. Someone needs to find this guy, Andy Rich, President, Composite Autobody, 277 Baker Avenue, Concord, MA 01742, and buy the molds from him. Change it to fiberglass and redesign to drop on the Miata backbone chassis as-is.

I'd buy a kit in the $4500-6500 range in a heartbeat (A perfect addition to the FM catalog in my opinion)



BTW, according to Google it looks like Vantage Motorsports in Cambridge, Mass is still in business.

wlkelley3 HalfDork
9/3/10 8:17 p.m.

Used to be a Locost Kit manufacturer local that used Miatas as donors. Was even featured in a GRM 7clone article a few years back. And had a tour of their facility. They have since gone out of business though.

Used a tube frame, Miata spindles w/brakes. engine/trans and diff. Had custom axles and driveshaft due to different wheelbase and width.

Keith SuperDork
9/3/10 8:33 p.m.

CMC, right? That's who made my kit as well, mine came off the line right after the GRM car. They talked up their "engineering" pretty well, but it turns out most of it was just dreaming. Definitely not custom axles. The driveshaft has to be changed on any Locost due to the rearward engine position.

I'm going to guess there are between one and two dozen CMC "Miata" Locosts out there. I've been in touch with most of the owners, including the two that have owned the GRM car since it was sold.


1/3/11 11:36 a.m.

The car in the pictures is mine. You cannot just attach a-arms to the original Honda frame. All early Honda cars are torsion bar lower suspension and not double a-arm. No matter what you do you'll have to build a new subframe to attach a-arms. Some of the race prep suppliers make Miata subframe assemblies to convert to rotary that are very light and can use normalized lower arms instead of the stock one. Since I had several subframes sitting in the shop I used them and then cut them out to accept the car and the 12a engine. The rear I just welded into place at the end of the box frame. These cars are not unibody but body on frame. So it's much easier to build a new frame out of box tubing.

Keith SuperDork
1/3/11 12:49 p.m.

Looking back at this thread - there were a number of people who wanted a frame/body that would drop right on to a naked Miata drivetrain. Well, that's now a reality! The MEV Exocet is exactly what you're asking for.

Styling is, well, challenging. That's dictated in part by the hard points of what's underneath - that stock radiator forces a fairly high nose. The "rollbar' is just goofy. But it shows what could be done. I don't know if there's a North American distributor yet.

mxseven New Reader
1/4/11 6:42 a.m.

I see that it's been about 9mos since I last posted here about my "FX5" Miata-based track car project. I've been averaging 2-3 hours a day doing CAD modeling over the last couple months, and have made some real progress! I just sent out an update to the email list I started, and figured I'd check the progress on this thread and give another update. Seems like there's enough interest now that I'll start a facebook page for my Paco Motorsports business and start updating the FX5 project there. I'll post here when that's ready.

Meanwhile, here are a few pics of the FX5 model. It has really taken shape over the past few months, though there's still plenty of work to do before I complete a build. Since the concept of the design has changed from a tubular chassis with aluminum skin to a semi-monocoque aluminum/steel chassis, I'm scrapping the rolling prototype I have and starting from scratch with this build:


Davidmach5 New Reader
2/13/11 8:18 p.m.

Here is a link to a bunch of parts on Ebay for Mazda Locost build


Have to put above full link in to get to parts.. also could search under Locost Thx

5/8/12 11:12 a.m.

Not to steal the thread, but I'm building a tube frame Miata now, with completely new bodywork. A link with many pictures is here:


Here's a Youtube of the first mule under it's own power: http://www.youtube.com/watch?v=g6x9OKXILfQ

Maybe the good folks at GRM would like to build one... :)

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