twotone's Miata Thread

[Teranfirbt]

Hah! The fiery devil's breath of the master accountant and the master schedulers (Are you going to be in budget and done on time?) make repair a distant third place consideration on most projects, although I generally sneak as much as I can in.

[twotone_ra64]

As a technician, I beg, with mercy and pleadings, that anything you engineers go on to create, ends up with “repairable” as one of the top goals.

Swan, I am ALL for that. In general though, what I've seen with the culture on Earth is that if the thing is broken, you just buy a whole new thing. Long gone is the concept of "oh, the thing is broken, let's fix it!" and now most things like phones, appliances, cars, computers, etc. aren't made to be serviced at all, only replaced. This is the reason I own older cars, and older model phones, and build my own computers.

When it comes to designing new hardware or building something for work, I always try to make it as simple as possible so that it's inherently serviceable. No fancy designs, just beautiful simplicity.

Hah! The fiery devil's breath of the master accountant and the master schedulers (Are you going to be in budget and done on time?) make repair a distant third place consideration on most projects, although I generally sneak as much as I can in.

And that's a major problem too, corporate really doesn't help when it comes to trying to design for serviceability.

[swan song]

That’s where good companies are made. The bean counters can save money, which is a good thing, but they shouldn’t have free reign. Their ideas for conservation should be weighed by a committee that includes engineers and techs, as well as the higher ups.

I fix a lot of Bosch appliances. They are a pretty good company. You can tell where the bean counter was allowed, and the engineer was able to make good decisions as well.

[Sigma Projects]

And like Derek said, it's usually easier to make a product meet its goals if designing repairable features in it are not a priority. Like glue instead of fasteners, usually stronger, can provide water/dust sealing, but non serviceable usually.

I fix a lot of Bosch appliances. They are a pretty good company. You can tell where the bean counter was allowed, and the engineer was able to make good decisions as well.

I wish my mom's Bosch washer machine didn't suck 

[swan song]

Pm me.

[twotone_ra64]

Before I left for school, the clutch hydraulics on my Miata were failing. One pedal pump couldn't hold the pressure and the clutch would slowly re-engage. I should have known, the clutch fluid would turn black VERY quickly, so a seal was going out in either the master or slave cylinders. I replaced the rubber flex line with a stainless steel braided line, thinking that was the issue. Yesterday I received new Exedy cylinders and replaced both (I believe OEM, after 221k miles?!) parts. I think the slave cylinder was part of the issue.

[twotone_ra64]

I'm thankful that I fixed the clutch issue so that my stepdad could drive the car around while I was away. But now that I'm home, a few more issues have come up. The first of which...



It's been nearly 5 years since I've painted this wing, but nature decided to undo my hard work. Granted, this was the first thing I ever painted entirely by myself, so I'm sure some noob mistake caused it to peel up. Now that the clear coat has peeled away, it looks so much worse. I could remove it for now, but then I'd just have holes in the trunk. You can also see some clear bubbling up on the trunk. I might have to get that redone as well.

Another issue is with water leaking into the cabin and trunk area. A worn rain rail, cheapy aftermarket window seals, and a botched rear window seal job are all the cause. It's time for a new top, too, so I'll have to save up a bit for a new Robbins top with new seals and a rain rail.

[twotone_ra64]

Wow, it's been a while since I updated this, and have I got some updates for you all!

Here's how she's looking as of last night. Notice the addition of the JDM Roadster front turn signals with the corner running light.



I don't think I'll need a new top at this point, as I have now identified the leak to be mostly from the rear window seal. I've patched it up with window rubber seal goop and that's now holding up.

The car needed smog, and failed due to increased NOx from the ignition timing sitting around 20 degrees BTDC?



I have no idea how that occurred, and how my car didn't ping. The only visual cue was the high idle (~1000 rpm). I purchased a quality digital timing light, adjusted the cam angle sensor to bring the timing back to 12 degrees BTDC, and then she passed no problem.

What I did end up upgrading and fixing are in the suspension, brakes, and drivetrain categories. I'll make a post for each category.

[twotone_ra64]

Suspension - the previous setup was KYB AGX with Flyin' Miata springs. The "poor man's racing suspension" setup from the early 2000s. While this setup worked fine, and the ride height was nice, I wanted an upgrade in both the shocks and tophat design for daily use. NB Miata tophats isolate NVH and hard bumps much better than the NA design, but cannot be used with NA shocks and springs.

I picked up a set of barely used Koni SPORT shocks with Flyin' Miata springs, both for NB, for dirt cheap. I had to buy tophat bushings and new bumpstops from Flyin' Miata separately, though. What was really funny is that, it was cheaper to buy a set of blown stock NB strut assemblies to part out the tophats from them, rather than buying tophats separately from Treasure Coast Miata or eBay.



I have a buddy with a stock, 160k mile, red 1990 A-package car and he was looking for an upgrade since his stock shocks were blown. My shocks and tophats were fairly fresh, so he bought them off of me, and we spent a Saturday swapping suspension!





And his car:



The best part was, after we had finished up and we ran to the bank so my buddy could get some cash, there was another red Miata there! Of course we took a pic of the trio.



The new suspension feels amazing, and the new setup dampens road force so much better than before. The shocks feel pretty similar, but the rebound is slightly better. My only complaint is that I gained an inch in ride height, as I was hoping the NB setup wouldn't change too much. The spring rates are no different between the FM NA and NB springs. I thought maybe the springs needed to settle. I called Flyin' Miata about it, and they actually recommended cutting a "dead coil" off the springs since they are progressive and there are a few coils that bind when the suspension is compressed, which would drop the ride height down 1". Not sure if I want to go that route, or wait and do a Ground Control coilover sleeve conversion in the future.

[Sigma Projects]

seeing all three lined up made me think of this


She's looking good.

[twotone_ra64]

Thanks man!

[twotone_ra64]

Brakes - there was nothing wrong with my original setup, and they worked just fine - however, my front rotors were in need of replacement. Trouble is, my front brake setup was another old mod from the early 2000s. It was the budget "big brake" upgrade from the Miata Performance Club of America that fizzled out in 2007. It was simply a set of brackets to adapt the stock brake calipers to custom 11" rotors, also provided with the kit. I had a spare set of new rotors, which I installed back in high school, but were killed after 4-5 years of hard driving, and became warped.

So how could I possibly upgrade this? Well, 01-02 "Hard S" Miatas, and all 03-05 Miatas came with 11" rotors and bigger calipers all around, and I found myself a set off of a 180k mile parts car from Facebook.



They were a bit dirty, since the parts car had apparently been previously used for rallycross, but nothing some brushes and Brakleen couldn't solve. Those calipers, coupled with new Centric rotors, Wagner pads, caliper boots and pad clips was the recipe I needed to make a bolt-on brake upgrade.

There is one concern surrounding these big Sport brakes - some 15" wheels don't fit over them. I was under the impression these brakes were bigger than my current setup up front, which also just barely cleared. My coworker had a few sets of TRM C1 15x7 +25 wheels for sale, and he let me borrow one to test fit.



The TRMs cleared with plenty of space...



...and so did my Rotas!



So it was just a matter of putting on all the rest! The rear brake dust shields needed cutting/bending in order to fit the larger rotors, but it was just a bolt-on ordeal. Even for the handbrake cables and function.



The new brakes feel great! I still need to find a straight strip to bed the pads, but I can tell the brake balance has certainly changed. Pedal feel is only slightly different - the 03-05 uses a 1" MC and different booster compared to my 1991's 7/8" MC and booster.

[twotone_ra64]

Drivetrain - while my diff was doing okay, aside from some harmonic grinding sounds in higher gears and lower RPMs, recently I felt some increased vibrations through the shifter that would occur over 30mph. And a strange extra whine coming from the rear end at highway speeds. I thought my diff was on its way out.

In preparation for an imminent diff explosion, I bought a beefer 7" Torsen LSD from a 1994 R-package Miata, with 137k miles on it. To swap a bigger '94-'05 diff into a '90-'93 car with a 6" diff, you also need a new, shorter driveshaft and axles (either stub shaft + half shaft style for the '94-'95, or '96-'05 full one-piece CV half shaft style). I went with the full one-piece CV style, brand new from Vatozone, which required pulling the stub shafts out of the '94 diff. The driveshaft is also a brand new unit from Flyin' Miata with serviceable u-joints! Wow Mazda, couldn't come up with that to begin with...?



For supercharger-proofing, a set of KMiata diff reinforcement plates went in. These little guys brace a weakpoint where Mazda designed a stress riser via two notches in the aluminum diff housing, where cracking can occur in high-power applications.



Finally, for longevity, new OEM axle seals, axle c-clips, and diff breather vent were purchased from Atkins Rotary.



And there's the pile, ready to go in! Peep the bottle of Redline 75w90 gear oil. Mia only gets the good stuff.



Thanks to the lack of rust under my car, popping the old diff out was really easy. Removing the midpipe, driveshaft, axles, and PPF bolts could not have been more straightforward.





I played with the original, 224k mile CV axles and driveshaft to feel if there was anything worn. And sure enough...



...that u-joint was shot. There was at least 1/4" of play in it. There's my vibration.

New diff slotted in with no difficulty. Like it was meant to be there!



I was able to button up, put all the axles in, slot in the driveshaft (with new, larger bolts for the d-shaft flange to diff!), fill up the diff, and check for operation and leaks. All good! Then, as I was putting my midpipe back on, disaster struck. The cheap Clampco v-band that came with my Goodwin Racing exhaust stripped as I was tightening it on... which left my exhaust look, and my car ended up sounding straight piped. I had to order a new Vibrant v-band with a replaceable fastener, thank goodness, and that solved the problem. Another thing to note is that the Vibrant clamp has two jam nuts - one for torquing, and the other which is slotted and is a lock nut. The Clampco only came with the slotted lock nut.



I just solved that issue last night, and finally got the car running. Nice to be no longer noise-violation loud!

[Sigma Projects]

Wow, lots of goodies.

[twotone_ra64]

So many goodies. Something in the rear brakes is dragging a little bit, and I'm not sure what. That, plus the final drive ratio change from 4.3 to 4.1 made the car feel reaaaaaally slow yesterday on a trip to Monterey.