STR MX-5, Part II

When we’d last left off,, the car was starting to take shape. With the suspension done, and the start of the power build, it was time to move on to the remainder of the updates.
This started with a Saturday of fun. First, removing the “noise tube”, which appears to exist only to add weight and make shock adjustment in the front a hassle. Took about ten minutes and $25 in parts. Easy.
Next, I moved on to the JDL auto design header. Very well-made, easy install (simply remove the passenger side motor mount, remove all the header nuts and the O2 sensor, and reinstall). Fitment was great, and looks pretty neat too.
The next bit, I feel less great about. The Goodwin Racing midpipe was pretty expensive for what it is, so I expected the same kind of quality I was getting from the HKS exhaust and the JDL header. I was wrong. The welds look like they were done by a drunk sweat shop worker, and the fitment is VERY poor. Lots of prying and moving stuff around to get it to fit without contacting the floorboard. If I had it to do over again, I’d pursue a different option. As it stands, its done, and there was quite the fun removing the old O2 sensor from the OEM midpipe.
Finally, I took care of the differential bushing inserts. Dropped the subframe a bit, disconnecting the diff mounting bolts from it first. Slipped in, reinstalled. Easy. Should be a little peace of mind not worrying about breaking one, along with an axle, as has happened to other STR competitors.
In and amongst all the other work, I got some 245/40/17 BFG Rival S 1.5s mounted on 949Racing 6ULs.
So, the car existed in this trim for about a week, until finally taking the car up to Karcepts for some fender rolling, tack welding the slip joint on the midpipe, and corner balancing the car.
I left there, headed to an alignment shop, where I basically just took Brian Karwan’s word for where I wanted to start, and got that done.
All that’s left is the tune, which I’ve got sitting in my inbox now, just awaiting some free time to get it onto the car, which is still being driven every day. All that’s left now is to get a mic setup working, flash the tune, and probably find a way to better attach the side skirts. Karcepts also makes a small endlink, used to replace the OEM headlight alignment rod in the rear of the car, which is neat, as it fixes headlight alignment with the lowered geometry.

And so the cat explodes. Thus time to revamp the entire system.

Well, the NB had been stalled for a pretty long time. After a good bit of DDing it, it started to get really down on power. It mostly happened when warm, and got much worse at higher RPM, so I assumed it was the pre-cat that had failed, given the already-present CEL for catalytic efficiency.

I don’t think I quite grasped the level of damage in my original estimate. Here’s what I saw when I unbolted the midpipe.

Awesome. Luckily, I’d already wanted to convert the car to Federal emissions. So swapped in a Federal 99-00 header, and started her back up. The problem still existed. After thinking for a bit about it, it became clear why. When this cat had failed, it had shot its dust and pieces everywhere behind it, clogging the secondary cat too.
Alright, at this point, I didn’t want to buy another stock exhaust. With the TT plans in mind, I knew a 2.5 exhaust was in my future, but also wanted something cheap. I went online, and discovered this $300 special. I had pretty low expectations, but after a few weeks, it arrived. The car drives great again, although, I have to imagine I’ll want a different rear section, solely for visuals…
Now that it’s a working car again, time to move on with some track prep, as the season is beginning shortly.

The STR Build Begins

After weeks of amassing parts, the STR build finally got started this past weekend.

It began with just an HKS Legamax Sports muffler. Easy install, as there aren’t many hard parts, just the two gasket bolts, and *four* hangers (only 3 are reused).

In its current iteration, its quite quiet, but I imagine it’ll get quite a bit louder once the header and midpipe are installed.

Next, the Karcepts rear sway bar. With plans to get the shocks on, I set the endlinks to the recommended length for the ride height I *would* be running here in an hour or so, and bolted it up. Very easy install. Some tight clearances, but none seem to be an issue at all. Great part.

Now, the hard stuff begins. Installing the offset upper control arm bushings up front was quite the undertaking, requiring disassembly of most of the front end of the car, and we were cutting out the front sway bar anyways to ease assembly.

Most of the difficulty was in the removal of the existing metal flange material, but the bushings went in easily, some clearancing done to the control arm to ensure no bind, and torqued down.

While the bushing install was going on, I bolted in the MCS dampers. This is probably the easiest shock install I’ve ever done. The hardest part was just one small hose clamp for the intake sound generator (I think this can be removed?), and the rear trunk linings. Also bolted the control arms back up at this point.

Finally, finished the install (which had been in progress all along) of the Karcepts front sway bar. The initial removal required a cutting disk, and some time, but install was just as easy as the rear.

The last step simply involved mounting up some Continental DWS 225/45/17 tires for all-season use, on some TRM 17×8 wheels. This’ll look a LOT better than the stock wheels for daily use.

All that’s really left now are some easier tasks; rear diff bushing inserts, the header and midpipe install, along with fender rolling and tuning. Hoping to knock this out in the next couple weeks or so.



2017 Mazda MX-5: A Return To STR

I suppose this began back during Spring Nationals, where my girlfriend decided it was a good idea to fly and drive, and codrive one of our friend’s ND MX5 in C Street. After running her HS Civic all year, she pretty quickly came back after a couple runs, and told me she was buying an ND. Great.

Now, I didn’t really know how this would affect me much, I didn’t have much interest in running a CS car, wasn’t a particular fan of the ND in that trim (or in general….), and I’d planned on keeping my C5 Z06 for the foreseeable future. Well, things change. I got offered much more for my Corvette than I’d expected when just posting a feeler for it, so it was removing itself as an option for 2018. I had a few options. First, was to go and buy a C6 Z06, the car I should have bought to begin with. I decided it was pretty foolish to go and keep spending money on ANOTHER new autocross car. So then, I was waffling between my BMW, and the ND in CS. I didn’t want to devote another season to chasing down BMW issues, at the expense of driver improvement and a desire to only lose based on *my* performance as a driver. I didn’t want to run the ND in CS, although that was looking like the option. I didn’t really want to go through the ordeal of ST prepping a car either. But, here we are…

During my 18 hour haul back from Lincoln, I decided I’d simply deal with the extra work and time to get this car prepped for STR, as they seem like a tremendous amount of fun to drive (although I’m keeping my expectations tempered in a post-Corvette world), and Brian Karwan at Karcepts, the shop who’s been building and doing most of the development work for parts and setup on these cars, is both a good friend, and local to me, having supported a lot of work on my last STR build. So, I decided to reach out to him about parts selection…

She went and finally picked up her 2017 MX5 Club in October. I’ve already got the Karcepts-Spec MCS suspension in my possession, supported by some Hyperco springs and helpers, and Karcepts spherical mounts. The remainder of the STR parts are on the way, and I’m looking to wrap up the car by the end of January, at least in a baseline trim.

2000 Mazda Miata – ES? NASA Time Trials? Spec Miata? Track Toy?


So, my girlfriend wanted a beater, I wanted something I could hit the track in (at purchase time, there wasn’t really any plan for it), and something we could take to small, local autocross lots without really worrying about safety concerns or tire cost.

Of course, this swiftly scope creeps for me, as with everything else I seem to do. I, of course encourage the purchase of a Miata, and ideally wanted something we could turn into a competitive autocross car.

We browse craigslist, and found a killer deal on a 72000 mile 2000 Miata. Great. Pretty quickly we went out, negotiated the deal, and picked it up.

So, we quickly realized there were a number of things that needed addressed with this particular car. First, it had a recurring check engine light. Failing cat. Okay, great, it’s a California car with two cats, we’ll pick up a stock header and swap that on, along with the requisite midpipe, O2, and ECU changes (total cost was rather small for this, I still haven’t gotten around to most of it).

Second, the early NBs had a really terrible center console. With nowhere to put even a drink that would keep it standing up, the first order of business was to swap on an NB2 center console. These are typically well over $100, but lucked into finding one a friend had, who was building an Exocet, so that swap happened pretty much immediately, and the car is substantially better for it.

That, along with my typical 1980s Alpine head unit install for bluetooth audio, made this a pretty decent daily driver.

Now that we’d gotten this thing in good daily driver shape, a few things happened. First, I’d ended up selling my C5 Z06 somewhat unexpectedly. So we needed a new plan for next year. Ally decided she was going to pick up a new ND MX-5, so that made this car no longer a daily driver, and resulted in her having 3 cars. I was down to one (STX 128i). I both wanted a beater, and figured this was definitely down the road of scope creep far enough, so I decided it best to just buy her out of it and continue building it out with my own money.

In the prior month or two, we’d already tracked down an OEM Torsen diff (found crazy cheap on eBay, still waiting to get around to installing this), along with some Koni shocks. They went on the car, along with some RE Suspension bump stops, a Flyin’ Miata 1in front sway bar, and the Racing Beat reinforcement blocks, as well as some Improved Racing adjustable endlinks.

I’d also picked up some very cheap OEM 15x6s, and takeoff Bridgestones from some local autocross friends as something to play around on. This stuff went on, and the car became a hell of a lot better to drive around.

Somewhere along the way of all of this, I’d swapped Hawk HP+ pads onto the rear, along with *TWO* valve cover gaskets (don’t buy an Amazon replacement for $9), replaced the shifter boots and bushings, done an oil change, and replaced the plug wires after one disintegrated upon removal to do plugs.

Of course, the next step was to actually get this out to an event…due to some parts availability issues for the BMW, we decided to bring this out. It wasn’t particularly fun or fast, given the stock alignment and open diff, and quite old tires, but was used to do a good test (results to be posted separately), and shake the car down.

With that, we decided we probably didn’t want to spend a whole lot of time competitively autocrossing this thing, especially with the ND arriving soon to be used for the 2018 season.

And that brings me to today. I’ve picked up a Hard Dog roll bar to put in, the ES suspension and wheels/tires are going away to eventually be replaced by a Whitener Racing setup, used some Hawk contingency to pick up some Street/Race front pads for track duty, and now am looking forward to getting back out on track, for the first time since 2011.

The winter plans include taking care of that, getting rid of this CEL by finally swapping the Federal setup on, along with getting the Torsen in and an alignment done. Hopefully, it’ll be ready to go come the end of winter, and I’ll also have acquired a hard top by then.