Odd Jobs

Lately it's been a lot of little miscellaneous jobs getting ready for the next big splash, which will be mounting the spaceframe chassis on the power plant frame. Getting these two parts together will be a nice "landmark" step, as well as freeing up a lot of space in the garage, so it can be used as, you know, a garage.

Rosie the Riviter Rides Again!

Taylor the Mighty is my most mechanical child. Or, at least, the most enthusiastic about cars, and she was immensely helpful riveting the belly pans on. Pops Racer has been making tube frame cars with aluminum belly pans for 50 years and had some well founded tips on this job including: a) 5/32 countersunk Apex aircraft rivets b) close spacing and zig-zag pattern for the rivets, and c) Hysol 9460 industrial two part epoxy. People also use Hysol e-120HP - the difference being 120HP allows two hours work time before everything has to be set in place. Work time for 9460 is 50 minutes. E-120HP appears to be completely unavailable anywhere (thanks again, global supply chain catastrophe). So with the time pressure, it was super helpful to have Taylor the Mighty's help getting 200 rivets done (200 per side; 400 in all). I'm sure it's possible to get good toy car results with a less fanatical belly pan scheme, but Pops Racer has tested this routine over the years and if done correctly the belly pan can add a great deal of structural rigidity to the frame.

Although the chassis is now ready to mount on the power plant frame, there are a lot of little jobs that are easier to do with the chassis off so I have been trying to get those sorted. Low on the excitement scale, but essential and probably much more difficult with chassis in place is the exhaust system. The donor car exhaust was in "mixed condition" - the actual tubing was sound, but most of the flanges were too rusted to be useable and the catalytic converter was completely used up (just an empty enclosure - no signs of the catalyst mesh whatsoever). My first idea was to weld new flanges on everything but the first set of flanges I ordered didn't fit. 

This was actually one of the better exhaust flanges from the donor car. Not confidence inspiring.

Then Paul the Actual Professional Mechanic Who Actually Knows What He's Doing warned me about convertibles without functioning catalytic converters: apparently you arrive at your destination smelling like gasoline. My lovely and long-suffering wife is even more averse to petroleum smells than most people, so this would be extremely unpopular and since I'd like to have her company riding in my toy car, and I'd like to be allowed back in the house after driving by myself, a functioning cat appears to be mission essential. Side note: having grown up in a race car shop on a farm, the two most nostalgic smells for me are horse manure and racing fuel. Yes, I am clinically insane. Oddly, I really do NOT like the smell of pump gas.

Then I saw a listing for the back half of an OEM exhaust with intact flanges on the local Miata forum for cheap. With that and the catalytic converter, and the prospect of welding on flanges that would not fit OEM or OEM equivalent Miata flanges, I just went ahead and bought a new down pipe. So the header is from the donor car, the back part is from a different 90s Miata, and the two pieces in between are new. 

Another side note: catalytic converters are moderately expensive... unless you want to be able to drive in California, in which case they are insanely expensive. Like, $1000 or more. I was grumbling about paying $125 for the "everywhere but California" variant. Sometimes we don't know how good we've got it. 

 Side note to the side note: have you noticed the proliferation of warnings on every conceivable product that they are all carcinogenic and cause birth defects in the State of California? This is going to become a classic case study in Alarm Fatigue, where people just start ignoring all the warnings because sifting through 10,000 warnings per day to find the one that isn't a vanishingly remote risk wouldn't leave any time for anything else in one's life.

Miatas of this generation come with a heat shield on the exhaust header which helps keep the engine bay a little cooler and avoid roasting things that don't want to be roasted. Also the engine likes to breathe cooler air. The donor car heat shield was useable but definitely 'weathered' and not really giving a vintage vibe. So I went with exhaust wrap as seen in the picture below. In the old days I think this stuff was asbestos. Now it's made of volcanic rock magically extruded into fibers and woven into a fabric by volcano-dwelling elves. 

It's supposed to do a very good job of lowering heat adjacent to the exhaust pipes. I had extra material after doing the header so I went ahead and did the down pipe and a bit of the tail pipe with the idea of minimizing heat transfer to the belly pan and thus to the driver and passenger. There is some controversy about whether this stuff promotes or inhibits exhaust pipes from rusting. My guess is that for a fair weather toy car this is not a major consideration. I do think the material is consistent with the vintage aesthetic and I like the look of it. Pro Tip: this stuff is like fiberglass but worse. Wear gloves and sleeves and long pants when handling.

Another aspect of the exhaust project. I am using Mk2/NB subframes and Mk1/NA power train, and there is no trouble-free way to get later model exhaust onto an early model engine or early model exhaust to cooperate with later model subframes. The main issue is the location of the hangers. So above is my hack/kludge/bodge solution (bodge is in the eye of the beholder). I brazed an extension on to the original exhaust hanger to get a hanger closer to the midline of the car. I am not thrilled about hanging the muffler at the end of this long lever arm, but there will also be hangers on the other side of the muffler and up forwards toward the cat, so I think this will be OK.

One of the most popular Miata mods is aftermarket exhaust; also popular for Miata-based kit cars. There are alleged performance improvements (probably marginal, not really relevant to me). I think the main reason for these is how they sound. Some I've heard - mostly the cheap ones - are just loud. I have heard a couple that gave a pleasing exhaust note without excessive noise - these are generally very expensive. Some of them do add nice appearance touches, but the OEM stainless tip is not bad looking and it's also quiet and cheap. Folks, we have a winner and the winner's name is OEM.

This is Not a Toy

Also delaying the Great Confluence of Chassis and Power Plant Frame have been a bunch of car and house jobs that are nothing to do with toys, and therefore annoying. The little white van (Mazda 5; a very under-rated vehicle in my opinion) needed new brake rotors and pads. Doing that job made me really appreciate how much easier it is to do all these jobs when there isn't a whole car in the way. So much easier to get at things and see things from the most convenient angle rather than the only possible angle. This is probably one of the reasons I'm enjoying this Ill-Advised Sports Car Project so much more than other auto wrenching jobs in the past. 

And also a bunch of kitchen stuff. A couple of added cabinets and then a whole new countertop were done by pros, but this still left me with a number of annoying jobs like removing and replacing the dishwasher and re-plumbing the kitchen sink. Our kitchen sink has not only the sink plumbing, but also a reverse osmosis water filtration system, a disposal, and hookups for a dishwasher, ice maker, and an outside faucet. So that's a lot of plumbing all crammed in to a fairly small space. Plus the new sink is lower and has the drains in different locations so the drain pipes had to be completely redone. 

Kitchen refurb that got in the way of my true vocation of building toys. The peninsula in the foreground is new, as are the countertops dishwasher and sink. I will put the stove back, I promise (did I mention my lovely and long-suffering wife?). There is a pending backsplash project which will get underway soon, using leftover tiles from when Sister Anne did a tiling job in her old house. The stools in the foreground are decorated with rosemaling; a Norwegian folk art tradition courtesy of A-mom. She did these stools for us like 10 years ago and we are just now getting around to the kitchen refurb for which they were intended. It occurs to me that there are a lot of DIY genes in my family tree.

This is a Toy

So continuing to putter with odd jobs before putting the chassis on. 

Got the steering rack and steering links bolted in place - so it's a lot easier to push this thing around the garage without the front end trying to go two different directions at the same time. 

Power plant frame still having a prolonged out-of-body experience.

Also got the shocks mounted. Bespoke shocks/springs are very popular in the Replicar crowd because the OEM shocks and springs are calculated for a car that's about 300kg heavier, so may be too stiff or the ride height may be too high or both. I have heard different opinions on this - some folks are happy with OEM coilovers. But even the happy people say OEM is stiffer than optimal especially in the rear. Due to a Series of Unfortunate Events I wound up with two new front OEM-equivalent shocks (brother Ray is a genius at finding great deals, these were $30/ea) and two OEM rear shocks from the 1999 Miata. Thanks to Miata John for putting the old springs on the new front shocks. Maybe the combo of new fronts and worn out rears will be just right? Or maybe I will wind up needing ("needing" is a very relative term here) bespoke shocks and springs. But I am glad I have an inexpensive alternative to use while putting the car together, and can defer the question of fancy shocks for later consideration.

Chassis with belly pans in place, waiting to be flipped over and mounted on powerplant frame.

So hopefully - barring new eruptions of trouble from houses or non-toy cars - I will be able to get the chassis and the space frame properly united this weekend.