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2021
I was focused on getting the car to the track, but it had other plans.
The 95-97 cars had the ECU behind the passenger seat and that wasn't going to cut it. So, I jumped on CAD, made a quick model, and sent it over to @Scaxx to cut on his CNC plasma table. Now the ECU will stay high and dry in the event of a rainy race.
Next I repurposed a Capaccino washer bottle for an over flow. It's worked OK so far, but an improvement is needed down the road.
Determined to avoid a "trash can" bumper, I went about adding an undertray and air dam to work with the Racing Beat rep bumper. Some 1/2" birch, lawn edging, and HPDE strip later I had an air damn that doesn't look like a knockoff from Rubbermaid's outdoor line. I also installed a set of Spiked Performance fender vents.
Early on the build I had bought a Wilwood 11.00"Dynalite kit. A used TSE 11.75" x .81" Superlite kit came up for sale for what I could sell the Wilwood kit for. They didn't fit the 15x9 TRM wheels though, so I was on the hunt for new wheels.
The biggest kick to the nuts came mid way through the year. Originally I had planned on running a stock BP4W I had laying around. It was of unknown history, but I could tell the head had been rebuilt. I replaced the valve springs and was just going to send it. After initially getting it running, it was found to be a little smoky. After a compression and leak down test, it was determined it was too unhealthy to move forward. Rather than chance another motor of unknown history, I decided to build one of my own with a lot of help from a friend. He sold me a slightly used set if FM Wiseco pistons. I also put in a set of Eagle rods into a machine shop honed block and topped it off with my old Spec Miata machined head.
I got creative with the oil line routing, but I ended up ditching the bracket to the manifold brace later on.
Now here's a build thread I want to get on board with. Real nice looking work so far. I was under the impression that it wasn't easy for the turbo/K-swap NA/NB guys to be competitive in GLTC. Interested to hear your feedback on that.
Unless there are big changes to the rules, NA/B's are out classed in every way. When I started down this path in 2020 it was more likely to see a NA/B up front. If I could start over, I'd go with a more modern chassis that could easily fit bigger diameter wheels. If I was sticking to Japanese cars, it'd probably go with a FT86, RX8, or maybe an IS300 if I wanted to still be a little "different". I also don't have the time to invest to improve my skills to the point of the top driver out here. They are on another level.
I wrapped up the motor build over the winter. I top off the block with the East Street SM head I ran on the NA motor and got everything read for break in on the dyno and some tuning. Thats when I started chasing other issues.
The first dyno trip started out well but then was cut short when the car refused to restart after a lunch break. At first we though it was a low battery voltage issue we had been dealing with. I had replaced the battery just before the dyno day, but the new battery was always a little weak. I found the closest FLAPS had one in stock, so I ran over to get it replaced under warranty. No help. After some diagnostics, we found that the injectors were no longer firing. My tuner is feared the injector driver in the ECU had fried itself (common failure on the AEM Series 1). I took it home to diagnose further. After talking to a trusted friend about the failure, he recommended reloading a map from prior to the failure. I did and the car fired right up. Another issue that popped up during the dyno session was a small oil leak. Initially, I thought it was the tee used to feed the turbo and pressure gauge sender (remote mounted). So I took some time to dig through the hydraulic adapter supplier catalogs from work to come up with a better solution for the tee. While removing the intake manifold to replace the tee, I found that the big banjo bolt on the VVT feed hardline was the source of the leak.
Everything fixed and I headed to the dyno again. We got further into the mapping. There was still a small oil leak, but nothing too concerning. We also ran into an issue where we couldn't get the boost under control. Even with the BW low boost canister, the boost was creeping up and keeping us from making the power target we were looking for. The SPM organic clutch was also starting to slip as he added boost down low trying to bring the torque in earlier. It had served me well for years, so I wasn't too upset.
I brought the car home and started off by trying to diagnose the oil leak. I cut off a section of bellhousing so I could start the car without a transmission hanging off the back. I found the dipstick o-ring had given up and there was some seepage around the rear main seal and carrier.
The last item I did in 2022 was installing larger hood vents on a hood with the worst paint adhesion ever.
Sick, love what you did with the front end, I too have an aversion for trash can bumpers. Also nice to know that's a knock-off RB bumper.. I was looking at those recently. How's it fit?
Sick, love what you did with the front end, I too have an aversion for trash can bumpers. Also nice to know that's a knock-off RB bumper.. I was looking at those recently. How's it fit?
The fit was Ok. Took a little tweaking to get it to fit up well enough. It's a little worse now that I've messed around with it to try to shroud the front tire.
After the dyno, the first thing to do was get the boost control in order. I ordered a Turbo Smart GenV wastegate canister so I could play with spring rates and changed to MAC valve for the boost control solenoid.
While checking everything over after the dyno, I found oil in the hot side charge piping. After a bit of research I learned that the -10 hose I was using was fine, but the fittings necked down to below the minimum ID suggested by Borg Warner for this turbo. So bumped everythign up to -12. Luckily, I had thought ahead and had a big enough bung welded to the oil pan.
New SuperMiata sprung organic clutch installed along with new rear main seal and dip-stick o-ring.
I was never happy with the Stage 8 locking hardware on the EFR application. Only being able to use the locking tabs on 3 of the 4 studs annoyed me. So, I searched for a different option. I found some titanium flange nuts with cross drill holes for safety wire. The only down side was that the flange was too large to fit in the relief cuts on the turbo flange. I don't have a lathe, but I do have a drill and some files. After a litle work, I was able to get the nuts to fit down into the reliefs and safety wire everything up.
Gridlife races are run rain or shine (and the rules state we need forward facing lights for that reason), so I decided to utilize the RB rep bumper for light and brake ducts. I bought some cheap foglights from Amazon (after I bough really expensive ones that were not going to fit). Then drew up some brackets in CAD and hit "pay" at Send-cut-send. Some left over IC tube and welding later, I had brake ducts and lights. I paired that with Foxhole Fabrication ducts and now brake temps shouldn't be an issue.
Third time was a charm at the dyno (mostly). We finally got the car tuned for GLTC. The name of the game is flat power in GLTC, so we worked to product as flat a power band as we could using tapering boost and cam timing. It's not going to break the internet, but it should be a reliable setup.
I did find that the increased drain size didn't completely eliminate the oil in the charge piping. I opted to add a Turbo Smart oil pressure reducer to the turbo feed to its not seeing the 72psi of oil pressure (cold) from the Boundary Oil pump. Since then, the charge piping has been dry.
Finally in December of 2023 I was able to get the car out to a rainy track day at Atlanta Motorsports Park. I only signed up for a single day (the following day moved to Road Atlanta, which I love, but wasn't willing to chance an issue in testing). All and all it went well. I got 4 of 5 sessions done. The billet (not Miatahubs) I'd purchased 2nd hand started to lose their preload after 4 sessions, so I called it quits. As I was loading it on the trailer, someone pointed out some oily rainbow coming from under my car. So, it was a good time to call it a day. Turns out reusing the aluminum adapters in the sandwich plate has been reused too many times lead to a bad sealing surface. I've since replaced them with Setrab hose ends that thread directing into the sandwich plate.
After fixing the oil leaks, I signed up for a two-day event at Barber Motorsports Park. Sadely it didn't go well. Oil leaks plagued me again. At first, I thought it was just the dip stick o-ring failing again, but I replaced it at the track, and it was still leaking oil. I was also seeing oil down the lower spin of the transmission. Rather than oil down the track, I packed up and went home early. This this only pic I got from the event and its previews the pain I signed myself up for.
As soon as I got home, I pulled the motor to give it a full inspection. I pressurized the crank case with about 10psi of air and found that the dip-stick was indeed a large source of oil and some air was leaking around the rear main carrier. I found some Viton o-rings for the dip-stick, replaced the rear main seal, pulled the pan to replace both half-moon seals, and resealed the seal carrier to the block. I repressurized the block and it appeared to be sealed. While the motor was out, I made a down pipe brace and a turbo brace. The turbo brace was a copy of what Emilio shared from one of their build threads. The down pipe bracket is a cobbled bracket and an axle tube clamp from a F-body. I also copied 5X Racing's crank trigger support bracket.
Gridlife South Festival @ Carolina Motorsport Park
I finished the Miami Teal wrap just a few days before the first race weekend and took it over to a local Dynojet to get some WHP numbers for classing.
I'll fill in the race weekend the best I can. It was a blur at the time and now its 8 months in the past. I had never been to CMP before this event. I booked a test day on the Thursday before the official weekend. Sadly, storms and rain were the story of that day. I didn't arrive until mid-day. The track was drying, but by the time I got out for my first session it was pouring rain again. With my limited seat time in the car, I decided to call it a day after one session on the track because I was not learning anything other than corner numbers in the rain.
Day 1 - Practice, Qualifying, and Race 1: My goal for the weekend was just to stay out of the way and bring the car home in one piece. Everything went ok for the most part. There was a knocking sound that I couldn't find the source of and smoke coming out of the car on the right handers. It wasn't until @Wingman703 informed me that my air dam was flapping up and down at the end of long straights that I discovered the source of the knocking. Apparently just cables weren't enough to support the undertray, but it wasn't something I was going to tackle at the track.
The smoking got so bad that I pulled off early of Race 1. After the car cooled off, I crawled under the car thinking that the motor was leaking again. The motor and transmission were dry, so I started looking around. Finally, another competitor who was behind me a few laps told me the smoke was coming from driver's side. Ends up the diff axle seal had failed. I keep spares, so I borrowed a garage spot from a fellow turbo Miata racer (he runs time attack) and had it swapped it out in less than an hour.
Day 2 - Race 2, Race 3, Race 4: After the oil leak was fixed and I could put it in the back of my head, I was able to start working on really breaking off the rust. I tried to make pace, but the car was a bitch to drive. Very likely due to the height weight (nearly 2700lbs) for the power I was running, soft spring rates, and tires that had been on shelf for 2-3 years. At the end of the weekend, the car went back on the trailer under its own power. Coolant and oil temps never got out of hand, if not too cool sometimes. I got to hang out with my best friend (who took some amazing photos that I need to resize to upload) and meet some new ones.
When I got home and did my post-race check list, I did find one failure. The ball joint on the Turbosmart wastegate started to pull itself apart. This would become a persistent issue that I had to create a solution with after 2 failures. Luckily one of the longer rods from the kit would work in a pinch. I tested it before the next race weekend.
What frequency are you running on your boost controller? I had this issue with a customers car, I took a video during a dyno pull, it was shaking violently. Changed frequency around until it was much smoother but still tunable. Also used ~10 1/16” drill bits to drill the socket for safety wire.
What frequency are you running on your boost controller? I had this issue with a customers car, I took a video during a dyno pull, it was shaking violently. Changed frequency around until it was much smoother but still tunable. Also used ~10 1/16” drill bits to drill the socket for safety wire.
A friend and I came to the same conclusion that it was fluttering with the smallest spring in the can. I'd have to go back and look at the frequency. IIRC I had to choose the closest one in the AEM to what the MAC valve states, but I might be confusing that with the IACV setting.
After the ball joint Turbosmart sent as a replacement failed the next race weekend is less than 1hr of track time, I designed my own "nuclear" option. A metal/metal rod end, custom clevis, all safety wired together.
While I had good intentions of updating this thread with my experiences at Mid Ohio, Autobahn, and Pitt Race from 2024. Life and preppareing for 2025 got in the way. My first race weekend was at Road Atlanta with Grid Life's sharing the track with Formula D. It didn't go well.
In practice, I had no power able halfway through. Pull in the paddock and find the wastegate rod failed again. The rod end broke at the threads just after the locknut at the canister. I'm theorizing my low boost demands is causing too much fluttering. Besides the broken threads, I found the ball was already loosening in the socket. My winter changes made the car much easier to drive and even with low boost I was able to start learning the car again.
For qualifying, I cobbled together a fixed rod, so I'd have boost. Two laps in the car starting to misfire. I pulled into the pits and my crew pushed on some connectors and wiring and it came to life again. I went out and completed a few more laps. To make sure my binding rod wasn't putting me over the power, I hoped on GL's heartbreaker dyno. 213-215whp peak. Right where I wanted to be with some tuning anyway.
Race 1. Go out, start the race, make a few moves and start to settle in and the misfire comes back. I pull off the track sounding like a Subaru. After swapping coils and inspecting the harness, I found the ground and signal wire to my #1 coil had pulled out of the connector. Easy fix....if I had brought my electrical repair box. Luckily my wife has not left with the kids to come watch the following day, so I call her and ask her to pack the box. After a late-night trip to a friend's house to get the box so I can fix the harness the first thing in the morning we're good to go.
Race 2. I fix the harness, just in time for the rains to come. I've only got a new set of Kumho V730's (not a good rain tire) and a set of shaved Falken 660s (a worse rain tire). The track doesn't appear to be collecting water, so I decide to go out and see how it feels. The spray was crazy until the field spreadout, but the track had enough grip for "non-rain tires". I ended up finishing 23th and turned the 21st fastest lap. My best results so far.
Race 3. Rain was similar. I move up a few spots at the start. Running the car on wastegate pressure on (no electronic control) allowed me to really pull out of the corners with limited wheel spin. The rain started to pick up and I was losing grip. After a few cars got by me, I decided to back off and just ride out the last few laps. Then disaster struck. Going into turn 6, I carried too much speed into the braking zone. I might have even had a little lock up, but ultimately, I was carrying too much speed for conditions. I probably should have been braking further right (off the race line), but in previous laps crossing the race line while on the brakes felt worse. Once I was on the soaked grass, I had no control. The grass is downhill from the track, so I was getting "pulled" to the wall.
My helmet hit the padding on the halo bar hard enough to give me a temporary headache and my next was sore for a few hours. Overall I'm good physically now. I attest that to buying good safety equipment and backing into the wall instead of head on.
After the car came to a rest, I thought. "that wasn't too bad, maybe some body work". I went to pull away and the closest corner worker gave me the "its fucked man, don't move" signal. Getting out and seeing the damage, I knew the car was done. After getting home and looking over it, I have confirmed that initial feeling (regardless of what other have said seeing pictures on the internet).
So look go for a part out listing soon. While I could find a clean NA/B shell and swap everything over, I can't do another 4 year build. Plus GLTC "rewards" cars that can use bigger diameter wheels & tires. I'm going to be looking for something turnkey (or nearly) that gets me back out there quickly.
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