build diary
<< | show individual entries | >>February 4, 2004:
I've been asked why I brush-painted my frame instead of spraying it.
Well, POR needs to be sprayed with the proper equipment - which I don't have. You can't buy it in rattle cans at Home Depot.
Flipped the frame over yesterday and finished the painting. Thanks to friends that build airplanes, I have a collection of cleco fasteners so I can do a better job of riveting the floor. Cool! Now I have to go drill a LOT of holes...
entry 85
February 5, 2004:
The floor is on!
I'm now officially Making Progress. It took about 4 hours of measuring, drilling and rivetting to get the panel in place and I was having fun the whole time although the drilling is a bit of a test of endurance. The aluminum floor panel saves about 20 lbs over a welded steel one. There are almost 300 rivets holding it on to the frame. Attention to detail really paid off with a nice clean final result. The cleco fasteners made a huge difference, eliminating any chance of the floor shifting on me and causing headaches - thank you Bill for the loan of the tools! The floor wasn't a perfect fit with about a 1/4" shift from side to side but it wasn't enough to cause any problems. The photos tell the story of how I put the floor on.
CMC has put some time-lapse video of the GRM build on their website. It's the closest thing I have to an instruction manual at the moment and it's also quite entertaining. I particularly like the video of mounting the front control arms. Where is everyone? Is it lunchtime? One guy is working while others stop by to play with the suspension parts once in a while...
entry 86
Time to rivet on the aluminum floor.
I started with careful measurements.
entry 87
Cleco fasteners were used to hold the floor in place as I started drilling holes.
They're easily removed so I could move them around.
entry 88
To prevent the floor from shifting or buckling as I drilled, I spaced out the holes.
A series of 5 holes in a row would be drilled in the order 1-5-3-2-4.
entry 89
Once the clecos were holding everything down well, I used a centerpunch to locate each hole.
They're 1 inch apart.
entry 90
I just like this photo.
entry 91
Partway through drilling 300 holes.
I'm moving the clecos around so the panel is well located in the section I'm drilling.
entry 92
Once every hole is drilled, I removed the floor to deburr the holes.
It looks like my measurements were pretty accurate and I hit the middle of the tubes. Whew!
entry 93
The rivets were installed in the same order as the drilling.
I've only put in every second rivet along the sides as I'll use the others to help hold on the unstressed bodywork.
entry 94
February 7, 2004:
A lot of people are watching this build!
I love to hear from you. And congrats to Geoff Davis, who just took delivery of his own CMC Miata kit. He'll have a website up before too long, I'm told. Apparently the wait time from CMC is now over 3 months.
Well, my ski trip today got cancelled when the Caddy wouldn't start (20W50 gets pretty thick in the cold), the Miata proved to be frozen to the car cover and my Subaru has a dodgy ignitor. And that set the tone for the day.
I bolted up the diff and flipped the car back over. Hopefully it will never be upside down again! Then I started cutting thrust washers for the rod ends. 32 of them, all which had to be within about 0.5mm of the correct length so that I wouldn't bend the brackets when tightening suspension bolts. CMC sent some pipe for creating these, but they only sent enough pipe almost do three corners of the car. Luckily, my local hardware store has short lengths of pipe in the correct diameter and thickness. A bit of an annoyance - but not as much as when I went to bolt up the control arms and discovered that the rod ends don't sit in the middle of the brackets! Argh. So I have to recut a bunch of the washers. This is probably one place where the GRM build had access to prepared items to speed things up!
More disturbing was the discovery that the right rear upper control arm is the wrong shape. I can modify it to fit but I want to make sure I don't end up with a slightly different length control arm on one side of the car than the other. It might also affect the bump steer in the rear - I'll have to do some measuring. Putting the left side arm on upside down made for a perfect fit, so it's the arm and not the slightly asymmetrical brackets causing the problems. It's still more accurate than if I'd made it, probably. On top of this my digital camera was throwing fits and I had a hard time getting photos. You'd think they'd last for more than 15,000 shots!
Still, at the end of the day I've made some progress. The car has suspension on three of the four wheels, the diff is in and the uprights are bolted in to place. I can now spin the wheels by hand through the diff! I mounted the front shocks upside down to keep the unsprung weight as low as possible. It'll probably cause no end of questions so I might put them back upright. The steering rack is also mounted in place and I'm getting ready to run the steering column. Hmm, I'd better get a test engine in there first so I don't accidentally put the steering through the water pump or something...
entry 95
The diff is in.
The big 14mm bolts I bought didn't fit through the small 12mm holes in the frame and the diff retainer. I wanted the tight fit through the diff bushings so I enlarged the holes!
entry 96
A small bit of grinding was needed to squeeze the diff into place.
entry 97
Cutting thrust washers for the suspension.
This involved a lot of careful measurement.
entry 98
After all that cutting (32 washers!
) I installed the control arms - and found that of course the width of the arm changes the location of the rod end. So about half of the washers have to be redone. Sigh. And yes, the shock is mounted upside down to lower the unsprung weight.
entry 99
This is not good.
The two upper rear control arms have different geometry! One fits into place perfectly, one does not.
entry 100
The offending control arm.
These brackets are actually 5mm futher back than the ones on the other side of the car as well.
entry 101
With some juggling of rod end placement, I can get the arm attached to the car.
But then it's misaligned (and skewed sideways) on the upright. A slotted hole would solve the problem here. I need to make sure the geometry hasn't been changed.
entry 102
The mystery bracket.
I thought it was for steering, but that's not making any sense unless I put another universal joint in place. There isn't one on the other side of the car.
entry 103
Getting ready to install the steering.
Since I don't have the key for the donor, the ignition switch (and steering lock!) weren't doing me any good.
entry 104
February 10, 2004:
Steve at CMC is going to send another rear control arm to replace the one that's off.
As someone who deals in complex, essentially hand-made turbo kits I'm not surprised to find small problems like this - particularly in an early version of a product. So far, none of the problems have stopped me from working on the car.
A componentry update. Miatas use the same steering column splines as Subarus. A co-worker gave me an unneeded steering column adaptor from a Subaru steering wheel (he put the wheel in his Corrado) and it fits perfectly. I'll have to make a plate to adapt the OEM Subaru flange to my Mountney wheel, but that's simple. It will also give me the ability to space the wheel forward and back depending on the thickness of the plate. The Miata brake flex lines aren't going to work with the frame so I'll have to get some custom ones made. There's a decision on the "OEM vs stainless steel" quandary and another few bucks for cost. When working on the wiring harness last night, I also realized that I'll need to get a set of coils from a 1.8 Miata instead of the 1.6 ones I have. The 1.8 ECU won't drive those 1.6 coils. Yes, it would be easier to use the 1.6 ECU. But I have plans for down the road. Oh, and that mystery bracket is for the steering shaft. Fair enough, I'll make that work!
entry 105