sanyarcosean HalfDork
4/28/22 10:04 a.m.

For as long as I can remember,  I've lusted over 2 cars..  The Ferrari Daytona Spyder and the Lotus 7.  I mean yeah, I'm a car slut so there is always something catching my eye.  Those two though, always at the top of the list.

I stumbled on a relatively inexpensive Daytona replica about a month ago.  It was on the other side of the country and priced almost within reach... but not quite.  This stroy is not about that car.  That one will have to wait.

Frustrated Sean thought "What about the Lotus?".  So I did a quick search and found that most all of the companies that were building frames are gone. Heck, even the books are out of print.  My search did turn up one lead.  Midwest Miata Parts had a reasonably priced chassis for sale.  I shot them a message on their website to see if it was still available and promptly forgot about it.

On to other things.  I needed a rear quarter panel for our sons 96 Miata M.  I had been buying some parts from a local kid and finally convinced him to sell me his rolling NA6 tub for $100. We hauled it home and sat it in the shop to wait to be cut up.

Another week or two goes by and I get an email from Midwest Miata saying they still had the chassis and just wanted it gone..  call us.  I had honestly forgotten that was even a thing. So I called.  The chassis was a roller when they got it in a "buyout" of Miata parts.  They didn't want it, but it had a Miata suspension, an driveline in it.  So they took it along, parted it and tripped over the chassis for too long.  It was time for it  to go.  A deal was struck and a road trip planned.

Pics from the seller

We love road trips together so last Sunday it was off to Ohio for the wife and I. We would drive out, stay overnight locally, grab the chassis Monday morning and head back home. It all went without a hitch.

The book that started my love affair with the "7"  I carried one around for years pre divorce hoping to build one. but it never happened and that copy is long gone.

Who needs a trailer when their project car weighs under 100lbs..  Look how happy Jessica looks!  She is a keeper!

I had about 2 weeks of prep time between making the deal and the road trip to pick it up, so we did some work to get ready.

I built a quick base for the lift that 1. Keeps the chassis from falling through and 2. sets it at ride height.

We cut up the parts car and saved anything we thought we could use. Biggest being the front and rear subframes

All tucked in and ready to evaluate.

First thing that jumped out at me was the general sketchiness of the suspension pick up points.  It looks like the chassis was beat around a little bit and things got bent and others just didn't look square to start with.

I even broke a rear upper off trying to straighten it.

So off it all comes..

I am a big fan of not recreating the wheel and the Miata suspension is great in its stock form.  Rather than transferring all of the Miata geometry to brackets on the chassis, (and maybe getting something wrong) lets just use the Miata rear frame rails and subframe.  Yes, it will add a bit of weight, but it shouldn't make a big difference in the scheme of things.

This should work.  Lets remove the rest of the rear body structure and get the factory frame rails in here..

Being that I'm a tad out of my comfort zone, I invited Andrew Nelson over to talk me through how he would tie everything together and support the rollbar.  Plans were hatched and the frame rails are tacked in waiting for metal to build the supporting structures.

Hopefully, I'll have more to share soon!


Robbie (Forum Supporter)
Robbie (Forum Supporter) GRM+ Memberand MegaDork
4/28/22 10:29 a.m.


bentwrench UltraDork
4/28/22 10:51 a.m.

I too am a fan of the Seven, however I would not have one to merely haul my golf clubs. It must be fully capable of a FTOD.

Adding weight to a 7 is a travesty, the cars entire essence is based on lightness.  These cars can cut corners and stop on a dime and give you change.

Building suspension is not rocket science, had Colin used subframes the design would have never been as popular as it has.

For the same reasons, I poo poo using single source donors, too many compromises. Once you leave the path of riotousness, slowness insues.

A 7 is not just any backyard project car, it is a race proven car design, and in my eyes anything less than the full monte will be multiple steps backwards.

This also affects the resale, for me as a seven buyer a subframed chassis would be instantly dismissed.

Sorry, is my fan boi showing? It's not too late to put those subframes in the recycle bin!!!

sanyarcosean HalfDork
4/28/22 1:03 p.m.

In reply to bentwrench :

Thanks for your thoughts on my build.  I appreciate your opinion.  If I was fixated on FTD, I'd be right there with you. That said, I'm not.  I've picked my direction, I'm happy with my decision. Pretty sure part of the magic of these cars was also the individuality involved in the builds.  Enjoy your day

Shavarsh Reader
4/28/22 1:09 p.m.

I'm always interested in anything with miata subframes! following along

akylekoz UltraDork
4/28/22 2:05 p.m.

I love a garage that looks like mine.  It even has a Fox notch tucked in the corner, that old dog could fund some serious projects if in one piece.

Carry on, looks like fun.

dculberson MegaDork
4/28/22 3:23 p.m.

While a "from scratch" suspension might be an improvement in some ways, the best car is a car that gets done and drivable. Good job diving in and making some headway!

BrianC72gt (Forum Supporter)
BrianC72gt (Forum Supporter) Reader
4/28/22 5:11 p.m.

In reply to dculberson :

Amen!  You could use the Miata subframe to build a jig of suspension pickup points, locate the jig under the frame, then build from the frame to the jig.  But that is one more project on top of the project.  If the goal is get er done, then Miata subframes do.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
4/28/22 5:20 p.m.

Congrats! It's good to see there are still Miata-based Locost builds out there in a post-Exocet world. Using the Miata rear subframe is not all that unusual. It's certainly been done a number of times and seems to work reasonably well.

The front, however, will affect the aesthetics fairly strongly and you won't be able to use the motor mount locations anyhow. For the front, I'd recommend sticking closer to the Locost design.


stroker UberDork
4/28/22 5:41 p.m.

Following intently...


sanyarcosean HalfDork
4/28/22 5:52 p.m.

In reply to Keith Tanner :

Thank You sir! I've got the front subframe sitting there for now.  I've had the same aesthetics thought as you.  I'll coss that bridge when I come to it.  I have your book on my buy list as soon as I find  copy.  :-)

BobTaylor New Reader
4/29/22 5:05 a.m.

Seven is not the best car for every roof, soft suspension, good stereo system, etc., but as for the driving characteristics - it will be extremely honest and reliable. In my opinion, Colin Chapman has created a real "scalpel" - in a surgeon it performs its functions clearly and precisely, gives life in some cases, and in hands of a fool it is no more than a very sharp cold weapon. I'm sure you know what I mean.

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