Have hit the limit on bodges with this board.. I've found a lot of issues that I need to resolve and there's enough of them that a respin of the board is in order to help clean things up and make it a bit easier to keep working.
Went through and added in my open-drain input circuit, protection zeners to the gates, extra pads to the gate drivers, status LEDs for power and gate output, along with some other quality-of-life fixes like diagnostic pin headers. Tested out fill zones for the FETs too.
Spent some time trying to get the fan controller installed into the Miata. Ran into a couple issues with wiring it in, fixed those up and got the power all working correctly. ECU sends it a PWM signal and the fans go crazy, scope it and there's a load of noise on the wires. Turns out that's driving the gate drivers crazy and they're switching the MOSFETs way too fast. So need to fix it up with some filtering, hopefully can get it going this weekeend.
Found my old Casio F105-W while organizing everything. The resin strap was disintegrating and I happened to find an interesting looking Apple Watch band that I wanted to use on the Casio! Unfortunately, it's not an apple watch. Turns out after a bit of cutting, trimming, and installation, the 38-42mm Apple Watch band fits perfectly on the Casio, and even matches well!
So, decided to totally redo my office as it's become a huge mess and is really annoying to get anything done in. Spent a ton of time re-sorting every box I have, throwing out lots of stuff, properly sorting things into smaller boxes, and amazingly, I ended up with more boxes, but also more room. It's crazy how much empty space was taken up by big boxes that were only partially filled, which led me to completely revamp everything. Way more efficient and easier to work in now.
Still waiting on the new fan controller boards, they're taking awhile to get in. Had the Miata at a couple local car shows and it's been running great, despite some overheating apparent in the clutch line causing the reservoir to overflow. I need to get some insulation on it or reroute the line entirely. Other than that, it's been a blast on 15 psi and is quite a lot of fun!
The fan controller was not as successful, unfortunately. It seems I have much to learn about comparators and op-amps, so I've spent some time researching and learning about how this stuff works, and spent time redoing a lot of what I've previously laid out. Found some big errors in my layout and some ways to fix things too, so hopefully will have a better-working board after all this.
Got the boards I designed in! First electronics projects where I've actually designed circuit boards! Super exciting, as eventually I've got some bigger projects I'd like to get into, such as building my own ECU for the car! This little test is for a motorcycle blinker conversion, to allow using a single LED in place of a dual-filament bulb. It works well!
With the -4AN line installed, there is *much* less oil in the turbo. Just a tiny little bit, as opposed to the Exxon Valdez level of oil spill that was previously pouring back out of the filter due to the recirc valve not being able to keep up (I've got a new one of those on the way as well). Hopefully this is where I can leave it, but even that small amount of oil has me slightly concerned, so I may just go all out and try to run a bigger oil drain, but we'll see.
Driving it more now, the current issue I've been having is problems with over-oiling the turbo. Currently running -6AN line, but I think that's providing a little too much oil to the turbo. It was leakign large amounts of oil into the intake and getting it through into the intercooler and even further. I've changed it back to a -4AN line in an attempt to lower the amount of oil going into it so it doesn't overwhelm my drain line. Weighed it with my new corner scales too, a scant 2351 lbs!
More work on the exhaust, getting the midpipe welded up, which has been a pain! Now that it's complete, I've gotten the system bolted up beneath the car, set up the muffler in the right spot as well and got it tacked up. All I need to do now is get the final pipe to the tip welded up and then comes bending and welding on hangers, which will be fun to try and position correctly.
Car starts and runs! Freaking epic. It's very loud though! Took it on a few little drives around the area to test for leaks and such, built 3 PSI of boost so the wastegate is operating normally! Now on to the exhaust system. Building it out of 3" stainless, which is an interesting thing to weld. Got most of it mocked up and tacked up, waiting on a bit more pipe to finish it all.
Welded up an intake pipe to attach my air filter to, and got the oil line hooked up and locked down. Turbo is installed, downpipe connected, and water lines are going in tomorrow. Still have to plumb in the bypass valve, wire up the boost solenoid and O2 sensor, and reinstall the radiator, connect everything back up and refill it. Needs brackets made for the top of the rad too.