The life and times of Miata #338

Keith Tanner said:

In reply to Snowdoggie (Forum Supporter) :

That sounds...cramped. I've spent a bit of time in 914 seats (in another vehicle) and I don't recall them being terribly heavily padded either.

Is wasn't that bad. First of all I had all the gear they told us to carry during snow season. I wrapped myself up in fairly warm mummy bag and ski parka. I had a pillow. I had a portable radio dialed to KOA where their all night talk show guy kept me company along with frequent weather and traffic reports all the way up I-70. I even had some food that I picked up at my parent's house in Denver to stock the kitchen of my mobile home in Edwards. Whenever it got a little cold I could just start up the engine and run the heater for a while. I had plenty of gas.

The 914 has a ton of footroom. More than some SUVs I have been in. I guess it is because Germans are tall. I used to be able to put both of my huskies in the passenger's seat, one on the seat and one on the floor, and drive them to the park. People would be surprised when I opened the door and I would pop out with two large furry dogs.

In reply to Snowdoggie (Forum Supporter) :

If Germans are tall then that doesn't explain the gigantic knee bolsters that Mercedes used to use that made it impossible to actually reach the pedals unless you sat straight legged, which requires hooves instead of tall-guy feet because of how low the pedals were to the floor.

The first thing I did to my Golf was rip out the knee bolster.  At least VW had an excuse: they had some crazy idea that if you had a knee bolster then you didn't need a lap belt. (which was the second thing I did)

So here's a photo of something you've never seen before: a 35 year old Miata.

338's official birthday is actually April 6 - Saturday - but I'm busy that day and the weather is supposed to be gross. So we were celebrating today. Why April 6? Because that's the day that we brought it home in 1999, and the car was built in April 1989 so there's a 1-in-30 chance it was built on the 6th :)

It's a dual anniversary this weekend, 25 years since lil ol' 338 joined the family, and 35 years since it rolled off the production line.

I had to drive out to the FM shop today and it was beautifully sunny and around 70*, so I pulled the hardtop and put on the tonneau cover. Might as well enjoy the perfect weather while it lasts. Unfortunately, while I was in meetings some high altitude cloud rolled in so you don't get the really pretty pics.

10 minutes down the road, I could hear a high pitched squeaking that was driving me nuts until I realized it was coming from the disassembled NC taillight sitting on the seat beside me :) Otherwise, it was just the slightly snarly and surprisingly deep OG Miata exhaust note and the engine's purr. No rattles, no squeaks, just a little cowl shake to remind me that they're a little wobblier without the hardtop.

Having the car sitting in the house garage - the one we use all the time - means I get to see it constantly. And while I celebrate the fact that the car is a real driver and not a garage queen, I think I'm going to call the local PDR guy and see if I can get a few little owies popped out. Just because we all deserve to look our best.

Apparently David likes pictures of cars at gas stations. I had to go inside to deal with a pump issue, and there it was all cute when I walked out. So here you go.

My old university roommate and best man was out to visit for the first time since 2007. I was living with him when I bought my first car, that other red Miata you've occasionally seen in this thread. He was here to clear his head after getting himself in a bad place. We had no particular plans, so we dropped the top on 338 and took a drive to Moab. Talking about music and films and family and laughing. Mission accomplished.

The road itself is about 44 miles of twisties along beside the Colorado river and under towering red cliffs. You can't capture the scale of it on camera.

338 was perfectly well behaved during the trip as you'd expect, but the small crack in the top meant a lot of wind noise on the interstate portion of the trip - especially the 80 mph section with a 20 mph headwind. I rarely use the soft top, but if we're going to take longer trips in this car I should do something about that. It's an almost perfect top by most aged NA standards, but it's not as good as new.

One thing we did learn on the trip - the soft top latch locks that I replaced in Jan 2023 (as can be seen a few pages ago) need some adjustment. They don't pop up flush, I need to grab a small allen and adjust them. I'm not sure if I can do that when they're on the car but it's not all that difficult to pull the latches if necessary. This didn't seem to cause any problems on the highway, the latches do go over center and into their fully closed position. But obviously the locks should work as intended or there's a chance the latches could let go. Good thing 338 doesn't have a super-harsh suspension that would put a lot of shock loads through those latches :)

We did also manage to ground out something at the back of the car on a high speed dip. My friend is a hefty fellow so we had a fair load in the car and I've put different bumpstops in the rear. I suspect it was the rear subframe based on my extensive testing of grounding out the rally car. No harm done. Probably.

Cool.

A fellow was selling a complete AC setup from a 1994, so I picked it up. Hard lines, compressor, evaporator, condenser, receiver/dryer, some sensors, even the bracket for the compressor. The nice thing about the 1994 setup is that it uses R134 instead of R12.

How different is it from a 1990? I guess I'll find out. One of my coworkers may remember. I'm sure I can make it work. One difference is the fan setup, which has the secondary fan controlled directly by the AC on a 1990 and by the ECU on a 1994. That should not be a challenge because I have factory wiring diagrams and I'll duplicate the factory setup. 338 already has a secondary fan installed (non-AC 1.6s only had one, AC cars had two) so I don't need to source one of them.

I actually have parts from a NOS factory AC installation kit for a 1994 that was kicking around FM when I got there in 2001, I think it's a new compressor and a few other bits. I'll have to dig out the box. 

Anyhow, this will make the car more pleasant to drive in our summer heat. Wasn't a big problem last summer but it's a good project and I don't have to actually turn it on :)

It's been hot. I need to get 338 on the lift and start the AC installation.

But last weekend was the FM Summer Camp. 338 wasn't on display this year for logistical reasons, but I did use it to run sweep over the Grand Mesa as part of the Sunday cruise. 120-ish miles, 70+ cars, some great roads. Some freshly paved, some a little rowdier that worked out the suspension. Not many pictures because  I was driving, but it was good fun. I did have to pass a pickup truck on the way up at one point and we were probably at close to 11,000' - I had the car at redline in 2nd and it was still a very slow pass. There's just not that much power in a 1.6 :) It did get me thinking about maybe some minor modifications like a header, though...

Nice and cool in the mountains, not so much when I got close to home. The tonneau cover did at least give me a bit of shade. Even in an event run by a major Miata modification shop, the near-stock survivor vibe was much appreciated.

I did notice the next day that the reinstalled hardtop had a big of a clunk over big bumps. I'm going to have to take a look at the adjustment of the rear mounts, this is a new trick. It only did it a couple of times but we do not tolerate such noises in this car!

I really need to get into the garage and install that AC. I was running errands yesterday and decided to take 338 because it was just sitting there looking so cute. I left the hardtop on because it was 99F and there was not a hint of cloud in the sky, so the high altitude sun was brutal. Yeah, I really need to get the AC installed.

But it still put a smile on my face when I walked up to the car sitting on the street amongst all the forgettable normal cars. Parked in the shade with the windows down :) It just popped because it was interesting and full of personality and painted a fun color.  So I had to take a picture.

That is all.

Still no AC. Why? Because I'm working on a second edition of one of my books, so I've been spending all of my spare time writing instead of wrenching. But I did need a picture of the factory front air dam and I happened to have a car equipped with one in my garage, so here's 338 looking all pretty in the late August sun and showing off a vintage factory performance accessory.

That is all.

Flyin' Miata needed a new development car, so we bought an almost stock 1991. It's red, has a hardtop and the R package front lip. If it wasn't on 15" NB wheels, it would almost be a dead ringer for 338. We've turbocharged it and it's currently sitting in my garage. Fun comparison. 

But 338 is about to evolve a bit. These boxes landed on my doorstop today. 

The big box is easy, that's a new Robbins top. Plastic window (despite what the box says), vinyl roof. Just like the one on the car - which is at least 25 years old and may be the original. But it's got a rip above the driver's window that makes it too noisy on the highway, so I decided I should make the car as pleasant as possible for road trips. There's no prize for suffering. This way I'll have an easier time convincing Janel to go on a run through the mountains with the top down since we won't have to put up with the noise as we go through the desert.

The smaller box?

Yup, the classic Jackson Racing CAI. I've decided I want to give the engine just a little more personality. A bit more growl from the front will help. I've also got a vintage header I might bolt on as well. Nothing radically transformative like a turbo, just a little extra scoot and fun noises. 

There's another box coming if USPS can figure out where my house is.
 

Hah, that's awesome!  I'm pretty sure you talked not just me, but also plenty of others out of buying a JR CAI 25 years ago...

Ha, I may have :) But it's era-appropriate, reversible and works well for what I want to do here. Definitely a better piece than the usual filter on a stick hot air intakes, while the new FM Randall cowl intake is a great value, it's not what I want for this car.  Same reason it still has the old shock tower brace instead of the new hotness that works better. 

I think it's perfect.  I remember them being installed by the dozen by whoever was selling them in the Crossroads of Time parking lot at Deal's Gap in '99.  Shocked to see them still available.  Was also the only time I ever met Joe Portas.  If you're spinning up minor period correct mods, it should have one of his knobs.  And a set of those air horns that only work for 6 months...

True period correct would be one of my collection of Voodoo knobs :) I'm honestly surprised it doesn't already have one. I have a Portas-modified one as well that I used to run on my own car, but I never liked them quite as much.  It already has the Crazy Red Italian (or are they Fiamms in this case?) air horns, they've been working since 1999.

The goal is not to throw every modification at the thing, it's to guide it to where I want to be. And I've got a decent idea of where that is.

BTW, the JR CAI is about to be rebranded Cobalt. Fair enough, since that brand is probably stronger these days. I'm glad I got one of the JR ones, although I seem to recall there used to be a JR logo embossed in the lid.

I wasn't able to start the work on 338 for a long time because I had Pepper, the R&D 1991, in my garage and poor 338 was sitting up in the FM shop. I'm done with Pepper for the time being so I have reclaimed 338 and it's time to get stuff done.

I'm starting with the AC and intake install. I've decided not go bother with a header right now because my header donor is not running and is in my trailer and I just don't feel like playing the game of musical work spots with a dead car right now. Besides, my main justification for the intake is the growl :) There's some overlap between the two installs so I figured I might as well get the AC parts in while the intake is out and I have more room to work.

I'm gonna document this in some detail because I find it interesting and my wife does not.

I started by digging out the remains of the NOS dealer-install AC kit that I've had forever. I have three new lines, a compressor, a couple of bags of hardware and the most useful possible thing: the instructions for retrofitting AC to a Miata along with all the parts numbers!

Mmmm, brand new hardware. And packed by John and Cheryl, which are unusual Japanese names. I think AC was a dealer installed option in 1994, was some or all of the AC kit made in the US?

Step 1 was to install the evaporator. Pull the glovebox, remove a piece of ductwork and stick it in place. There are cutouts in the heatshielding on the firewall for the lines to pass through (removed here) and rubber plugs on the holes in the metal. Same with the drain hose.

Problem: I didn't get the grommets that replace those plugs. Ah, but I am a pack rat and FM used to run a salvage operation. Just a few months ago we purged a bunch of random stuff that had been sitting around for a while and I felt the big bucket o' grommets might be useful. I was correct! I had several of each.

The wiring harness for the thermostat was already in the car, tucked out of the way and anchored with a piece of blue tape for easy identification. You have to know to look for it as it's up out of sight, but that's where the instructions came in handy. It's a simple matter to clip the tape and plug in the harness. Thank you Mazda for making this so easy.

So, interior part done. Current status: doing a full inventory of all the other parts and trying to decide what I should replace. Mazda doesn't have any receiver/dryers in stock but generics are available from O'Reilly. All my new hoses have new o-rings on them but of course they're 30 years old, so I'm going to order new rings as well. So now I have to wait until Tuesday. No worries, I have a few other things to work on...

Who made the components?

I recall that a Major Japanese cooling system supplier had a HQ in SoCal.  Calsonic?

I'll have to look to see who made the various components. Forgot to check today.

Even with my "complete" AC system and the NOS installation kit, I'm missing some parts. One is the HVAC control knob that has the AC button in it. Did you know that all NA Miatas have the button underneath the control knob? If you pop the knob off and press the shaft, a little "AC" light will come on underneath - even if the car doesn't have AC. It's a fun practical joke. Anyhow, I have a coworker who is getting ready to rid himself of AC so we did a little swap.

I proceeded with what jobs I could do whilst waiting for the seal kit to show up. One was to mount the compressor. To make sure the threads were good in the block, I ran rethreading tools through the mounting holes. This block was hot-tanked back when I rebuilt the engine in...2001? and I painted it silver because I thought that would be cool. It's looking a little aged now but the threads were pretty good. 

I forgot to pick up an AC belt when I was at the shop on Friday and I won't be back there until January. So I stopped by to pick up a belt from Autozone, which cost more than twice as much as the one from FM - and FM will ship it for free if it's part of a slightly larger order. That's my last visit to Autozone. I did discover that I am not willing to drive an hour to save $25, though. It was close.

Compressor mounted, I decided I could finish the intake install. This didn't go quite as smoothly as I'd hoped - the plastic parts didn't drop in to place as well as they should have. Poorly molded, poorly designed or was there something different about my car? The only real difference was (of course) a replacement stock style radiator. It appeared to be making contact at the forward edge of the tank so I had a little hammer talk with it. Good thing it's metal!

Didn't help as much as it should have. Based on the fit of the flexible SCAT-style hose, I think it's a design/specification problem. Still, it's in.

Now, one of the more challenging parts. I didn't have the wiring harness required. It involves a slightly complex relay, a plug for the pressure switch, a plug for the fan and it attaches to a connector over by the charcoal canister. Of course, it's also NLA. I wasn't quite ready to yank one out of my coworker's car because of the implications it might have had for his aftermarket fan setup. I did have one of the relays in my "relays" box, though. At least, it sure looks like one and has the right bracket on it.

NA6 Miatas only came with one fan if they didn't have AC. The second fan is only used for AC and they are completely independent. Years ago, I added an AC fan slaved to the primary because 338 was struggling with cooling under high load and high altitude when Mom and Dad were visiting.  It was a very simple relay setup, shown here with some wire loom removed. Brown is hot when the primary fan is running, blue is power to the secondary, grey is ground and it's controlled by a generic relay.

Unfortunately, to get power for that second fan I cut into the power supply for the AC fan right by the connector for the AC harness. Not ideal. So I had to reverse this modification. Took some clever work with the crimper and a bit of harness unwrapping, but I got it done. Before picture below.

Over the years, I have accumulated three large boxes full of random Miata wiring. It's a good source for high quality connectors and wires that happen to be factory colors. But that AC connector looks to be unique in the car. I was getting ready to have to go on a splicing festival when I pulled the protective plug off and  realized it had rubber plugs in it. I popped the rubber plugs out and discovered it was a connector housing just missing the terminals. Sweet!

I then spent some time rooting around in my wiring boxes and started scavenging terminals of the appropriate sizes with the appropriate wire gauge out of various connectors.

After some work, this happened. .

I also found a connector to match the relay, luckily it's a very common style in the Miata harness. The wire colors don't match OE but since they're only used inside this small harness, that's not a big deal. I did make notes on my wiring diagram so I didn't curse myself too much in the future.

The only thing left for the wiring is the pressure switch. I haven't found a connector that matches the pressure switch on my used hard lines. I may see if I can find one at a place that salvages Miatas. It's different than the one used by the 1.6 so I'd have to modify the stock harness anyway. I can jury-rig the wiring at the switch easily for the time being.

That's as far as I can go without the seals. I'm tempted to pull the car off the lift and take it for a drive so I can hear the new growly intake, but maybe I'll just dive into doing the top instead. I should probably check that the relay works as expected too...

The AC parts have been delayed. I could have had the receiver dryer on Saturday but those gaskets are taking their sweet time. I could have possibly used my generic o-rings, they'd better fit better than that.

Anyhow, in the meantime I've been tidying up a little. Remember how I said I had a lot of wire from Miatas? This is the organized box :)

I've also got a huge collection of random fasteners/brackets/plastic doodads. For example, when I was looking for a hood prop clip, I found at least three before I stopped looking.

Speaking of which, the car has a very slight lift to the side of the hood. You can't see it except from the driver's seat, but the panel fitment from that angle was bothering me. So I pulled off the hydraulic lift and retrofitted the old hood prop kit that I'm pretty sure came off 338, or more likely an old version of the Targa Miata. It was an accessory to the old FM shock tower bar. The JR CAI requires a hood prop move so it seemed right. It lifts the hood higher than stock and is out of the way. And it's how I always had my NAs set up.  I had to recreate part of it because I couldn't find all the parts, but it's in. I can't tell if the hood sits better or not.

I also took the opportunity to install an audio upgrade. A fellow was ridding himself of a stock NA6 radio/CD player and he says the CD works! Cost: price of shipping from Canada. 338 had decreased volume and very little treble on the passenger door speaker, so I decided to pop this in.  I have no need to play CDs in the Miata, but I also put an analog wired car phone handset in my M5 for the same reason - because it makes me smile.

The CD player was a pretty expensive accessory back in 1990, and almost none of them are working today. I still have the CD player from my old Miata but it is inoperative. I'll test this one later with a CD, but it did solve the sound problem on the radio.

For those of you who have been in the Miata world for a long time, you may remember Jeff Anderson. He was a character who found a few ways to improve those stock head units amongst other things. We lost Jeff fairly recently, but I had him tweak the head unit in 338 in 1999 at the Miata World event in Dallas. I had completely forgotten he'd signed it. I may send this off for refurbishment to fix that dodgy right channel but keep Jeff's modifications.

And just because I want to show off - I previously had the factory 1 DIN(ish) "sunglass holder" under my head unit. They were not completely uncommon. But this big 1.5 DIN(ish) cubby is - it was found on the base cars that had no radio. NLA forever but very useful if you have gone to an alternate head unit like I did on my blue 1990. I'm hanging on to this one just because I might want it someday.

Nice catching up on this thread, even though I'm without a Miata for the first time since 2018.

Flyin Miata could offer 3D printed repops of the  cubbies pretty easily.

In reply to Floating Doc (Forum Supporter) :

I'm not sure how much demand there is. Since it's an almost but not quite DIN opening, it only really works for things like my other car where I built a custom gauge panel and hid the stereo. Most people are interested in installing screens now so they want that space, and if they want an old school head unit you want one of the tombstones that has actual DIN openings and thus doesn't fit these special cubbies.

An interesting idea I've seen is to move the HVAC controls down low and move the screen-based infotainment above them. This involves a custom tombstone so a drop-in version would have some appeal. But it wouldn't be cheap. Might make for a fun project though. Maybe I'll look into that for the new NA6 project car.

You know, there was a time when I could pull an engine, working alone, in about an hour. I could swap transmissions between sessions at a track day. I have obviously reached my puttering era if it's taking me days to install an AC system on this car.

Anyhow, it's all in. I didn't take a lot of pics on the last session because I forgot my phone in the house, but it was an exercise in problem solving thanks to some bent pipes in my donor parts. I had to realign one of them fairly heavily but since they're fairly convoluted it was hard to tell what bends were OE and which were, umm, "aftermarket". I got there, though. Lots of shiny new factory brackets and isolators too, which is nice. The factory brackets helped tell me what the correct shape for the lines was too..

One thing that did give me trouble was the receiver/dryer. As mentioned earlier, this is an aftermarket replacement. The original is slightly larger in diameter so this one wouldn't fit in the factory clamp. No worries, it came with a bracket of its own that bolts on to the same place the clamp does. But it was the wrong angle, too long and had the wrong hole spacing. So I cut half of it off and redrilled the remainder. That worked - the picture is pre-drilling. Also, my AC gasket package was generic o-rings, I should have just used the ones I had. Oh well, hopefully there will be no leaks.

I also found out that the pressure switch on my donor lines doesn't seem correct. All the pictures I can find of them show a pigtail attached to the switch, whilst mine takes a very particular connector. I might just buy a new switch and change it out. I won't get a chance to try and charge the system until January anyhow.

Anyhow, it's all sealed up for now so I could take the car for a test drive and check out the new intake noises! And it did not disappoint. There's a new deep growl under acceleration. It sounds different than a more open intake and I quite like it. Not the howl of my ITBs on my high compression engines, it's more MGB-like. The nice thing is that it's purely related to throttle position so it should still be fairly quiet at cruise. It does make the engine sound more powerful than it is, but I'm okay with that. Throttle response feels better as well but that could be psychological from the noise.

Power gain? Hard to say, but some magazine called "GRM" tested one on their project car nearly a quarter century ago and while they didn't post the charts, they did see peak power jump by 4 hp and torque by about the same. They also made comments about increased torque in the low range. I'd believe that, the car is very tractable. Between the way it's driving and the noise it's making, I'm quite satisfied.

There is one thing, though. The loss of the stock airbox has revealed the stock exhaust manifold. The heat shield is missing which may have been removed because it was cracked and buzzing - they do that. That's fine, I'm probably the one who removed it years ago. But the manifold is crusty looking. I could either take off the mounts for the heatshield and clean it up with some fresh paint or Cerakote, or I could get a replacement heatshield. I've decided against a header because I know they affect the sound of the car and I'm quite happy with that now. Thoughts?

One thing that was also obvious on the drive was the change in sound from the Jeff Anderson-modified head unit and the new one. Jeff's mods really did pump up the output of the headrest speakers as well as drive some more bass. I'll look into refurbishing that one since it's just sitting on the shelf now.

I'd love to clean the heat shield brackets off and have it cleaned up and coated.  It looks way too nice to bury under a shield.

Forgot to mention - that hood misalignment I could see wasn't from the hydraulic struts. In fact, you can see it from this picture from when I drove it to CO before the hydraulics were installed. It's visible on the left side of the hood, you can see it sits slightly higher than the fender. Well, you can if you've seen it in person. It's a very small problem but it's in the worst possible place from the driver's point of view (literally).

Hood alignment is black magic, but I loosened the nuts and gave it a little pull over to one side because the panel gaps were ever so slightly tighter on one side. Less than a millimeter which is in spec (5mm +/- 1.2) but it does seem to have helped. I really only notice it when driving so it'll have to wait for another drive to be sure. I also repositioned the hood latch.