NSFW Posted August 24, 2018 Author Share Posted August 24, 2018 And I'm working on an Arduino-based controller for my new exhaust AVCS cams, as noted in this long-neglected thread: http://www.romraider.com/forum/viewtopic.php?f=7&t=11237 Yesterday I wired an AVCS solenoid up to an Arduino, which is (hopefully) the last hardware challenge... the interesting work from this point forward should all be in the software area. That's progress - I'm a lot more comfortable working in software than in hardware, and this project (in addition to break-in mileage) is a prerequisite for tuning my new motor. The exhaust AVCS controller is working now. I had no idea what I was getting into, but thankfully I know some people who know hardware, and they taught me a thing or two. They also told me to buy an oscilliscope, which turned out to be enlightening, after I figured out how to use it. It's kind of hard to show the controller working, because the only moving parts are inside the engine... So here's a picture of the signals from the crank sensor that I added (the top trace, with the big square pulse), plus the factory cam sensors (the funny-shaped pulses in the other two traces). Somewhere along the way, my AFR sensor stopped talking to my computer, but once I get that figured out, I can start turning up the power again. It's been a long time coming. Link to comment Share on other sites More sharing options...
NSFW Posted April 21, 2019 Author Share Posted April 21, 2019 I've been running the car at wastegate boost ever since getting the new motor, and playing around with driveability tuning, MAF scaling, the AVCS controller, etc... but I finally started turning up the boost last week. It's a little awkward now. Back in the day I did most of my logging on a long straight one-way one-lane stretch of road that no longer exists. So now I'm using 3rd-gear pulls to tune the bottom half of the rev range, and 2nd-gear pulls to tune the top half. It's not ideal, but I think it will work well enough. I'm running it out to 8000 RPM now, which is about 65 mph in 2nd gear. Freeway on-ramps are fun. I'm not sure what that 8000 would do in 3rd, but I suspect around 100. My last couple of pulls were around 17.5psi, with the MAF measuring about 310 g/s. When I had the car on a dyno years ago, I was running 22psi and the MAF topped out at 337 g/s, and that was enough to make 377whp. My pseudoscientific arithmetic says that I should just touch 400whp by the time I'm done tuning the "new" (couple years old) setup. Link to comment Share on other sites More sharing options...
boxkita Posted April 21, 2019 Share Posted April 21, 2019 That's cool! So GB is coming this summer? Build my car Boxkita Track days Link to comment Share on other sites More sharing options...
NSFW Posted April 22, 2019 Author Share Posted April 22, 2019 That's cool! So GB is coming this summer? Thanks! I really bit off more than I can chew, but met some people at work who helped get me through it. Group buy for the AVCS Controller? No, no, I need another project like I need a hole in my head. But if you want to build your own, everything you need should be here: https://github.com/LegacyNsfw/AvcsController I just noticed that it's missing the schematic for the cam sensor interface, but I can fix that. It's two resistors and a diode if I remember right. I have it on paper,but I need to make a presentable version and add it to the GitHub project. I'm kinda kicking myself for not doing a proper diagram of the Arduino shield when I was done. The shield itself just has traces like a breadboard, and I soldered components and wires into it based on hand-drawn schematics, making up the layout as I went along. It would have been smart to document what I ended up with. (Especially now that I know it actually works.) If you want something almost turn-key, Pantera EFI (http://panteraefi.com/) makes a single-channel VVT controller for $200... it was meant for GM V8s (single cam) but I suspect you could run one per exhaust cam with minor changes to their software, and the guy who runs the company seems to be into custom jobs (air boats, stationary generators, race cars, etc). He doesn't have much of an online presence, and the VVT controller isn't on his web site, but he posted a little bit about it here: https://ls1tech.com/forums/advanced-engineering-tech/1908016-diy-vvt-controller.html Link to comment Share on other sites More sharing options...
boxkita Posted April 23, 2019 Share Posted April 23, 2019 Hmm... cause I need more stuff to work on. Thanks for links. Build my car Boxkita Track days Link to comment Share on other sites More sharing options...
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