Build thread

[speedjunkie]

I replaced the wideband sensor this week and got some more logs. I didn't see anything dropping out, but I did notice in the logs that it looked like fuel pressure was dropping while TPS was held at 99%, and then the ECU was going into protection mode to save the engine.

Joe said that he was seeing a cyclic pattern in the triggers that looks like noise from an outside source and suggested moving the CAS wiring further away from the alternator, and I finally did that last night. I also wrapped the wires with foil tape and grounded that tape to the chassis and engine.

I took the car out tonight and got a few more logs. The first few pulls were really good with just a few slight hesitations, but they were so minor they were almost imperceptible. But the problem came back after the first few pulls.

I jacked the car up the other night and looked at the gauge on the fuel filter and it looked good. Then I watched a video saying to idle the car when you check the gauge, and that makes way more sense since it's a pressure differential gauge lol. So I'm going to put the car up again and run it this time, but I'll probably end up swapping the filter anyway just in case. I'm also going to check the pick up on the fuel pump, and if the problem still isn't fixed, I'll send the pump off to get tested, or just buy a new one. I've been considering going brushless and PWM, but I'm not sure I'm interested in that amount of work during the only months I can drive the car.

[speedjunkie]

I checked the fuel filter gauge while idling and it still looked good, but I swapped it anyway. i bought a new fuel pump to swap in as well that I should get by the end of the week, and I changed the oil.

When I was under the car I also noticed part of the diffuser missing, one of the vertical sides in the middle. Not sure what I hit, but it did some damage.

[speedjunkie]

I swapped the fuel filter and pump and it made no difference. I talked to Chris Ludwig and he told me that they had issues like this a few times and asked if I had another ECU to swap in to test. He said to recreate a map from scratch because the current one could be corrupted, and he said that has helped in the past. He did say that the logs of the pulls where I had no issues did look good, so that gives me hope. I also need to set up the knock sensor limits.

The pump I got was a bit different, stamped differently. I was concerned that it might be fake, even though I got it from Summit. But I'm guessing they just changed it since the last ones.

[speedjunkie]

I haven't done anything else to try to fix my current issue lol. I'm going to upload an old map and see if that works.

In the mean time, I picked up an RX-8 4.44 diff from Jeff, so I'm now looking for an extra FD diff or case that I can swap it into. If it's lower mileage than my current diff or in good shape still, I'll save that one and swap it into my current case. I'm also considering swapping 1st and 5th gears so 1st isn't absolutely useless like it almost is with 4.10 gears, and so I can keep a good RPM on the freeway in 5th, but I also like the idea of increased acceleration in 5th so I don't have to drop a gear to pass someone.

The guy in England that has been working on my CAD file for the display has been coming up with more ideas and now it's going to be in two pieces, the center will be separate, that way if I ever have to change the center part I won't have to print the entire thing again.

[speedjunkie]

Pretty excited about this update. The file is just about finished.

It's been a bit confusing because there are some optical illusions between the headlight and cruise buttons and the holes for the warning lights. And my scan wasn't great so he had to recreate the Audi portion from scratch, and then deciding how far it should protrude from the surface, if at all. But I think this version looks great. It will be two separate pieces so if the display changes, I can get the center portion changed and printed by itself without having to print the entire piece again. He's going to add holes for threaded inserts too.

So now that this piece is so close to ready, I guess I need to get moving on writing the image for the Pi and designing the gauges. Although EFIAnalytics is supposedly writing the image, so hopefully they get that finished soon and I can design the gauges. Although I've also thought about seeing if ChatGPT can design the gauges the way I want lol.

Messenger_creation_3ABECE85-A318-472E-9A9E-6EC88D648321 by Eric Jausel, on Flickr

Messenger_creation_FFEED26E-AB09-457A-B724-1F796FFDA69D by Eric Jausel, on Flickr

[speedjunkie]

The file is finished and emailed to me. He included a test print to make sure the center surround will be the right size for the display, so I'm trying to get that printed now so I can move on with this project and hopefully finish before winter lol.

I got into ChatGPT and had it write some code to create gauges, but I'm not sure whether it will work. I don't know how to add gauges to TunerStudio yet.

[speedjunkie]

I uploaded the files into Craftcloud last night and ordered them from Loop 3D Additive Manufacturing in the UK, printed with SLS PA12 Nylon so it's stronger and heat resistant. I should be getting it the 2nd week of July, so turnaround isn't too bad.

And I ordered some heatserts from McMaster Carr last night for pressing into the dash pieces, so it'll use machine screws instead of the ones the stock pieces normally use that eventually break. Then I can make a mount for the display to the dash pieces.

I'm really considering seeing if someone can design the gauges for me, and hopefully the image is written soon for TS on the Pi5, those are the last two things I need to do.

[speedjunkie]

I got the dash a few weeks ago and have been modifying it a bit so it fits a little better, but it did fit pretty well right out of the box. I've heated up and reshaped part of it, and sanded here and there, ground off a bit so it doesn't stick out as far. It's about as good as I can get it, and I've noticed that there are some things missing from it that the stock piece has. The stock piece has a couple pieces that snap in behind the neighboring piece to hold it in place, and those would really help me out because that's the part that doesn't fit as well, and it would fit perfectly now if they were there. It also doesn't have a mount for the display on that bottom corner, so I have to figure out something there. I need to sand it some more, then use filler if needed and paint it. I started making the screen mount last night, I need to make the four brackets to mount it to the hood still. I pressed the heat inserts into it but only for the center piece and the headlight and cruise switches. I will say this thing is SUPER strong.

I designed the gauges, a few times actually lol. I've come up with several different designs and I'm pretty close to finished on them. But I still need to figure out the image for it.

I'm still having the boost issues, and I've been having issues with it hunting for idle while warming up and dropping too low at idle and dying and not wanting to start again, although that doesn't happen often. It's weird though, because it sounds like it has no compression at all, and then a few minutes later it'll fire right up.

I haven't done anything with the diff yet, I'm still looking for a case for it, or another good 4.10 diff in case I don't like it.
20250716_163506 by Eric Jausel, on Flickr
20250728_215913 by Eric Jausel, on Flickr

[speedjunkie]

I wasn't making any progress on getting the OS image written for the Pi, so I sent it to OneGauge so Mike could get it running, that way once I get it back from him I can install everything and be done with this project. I've been working on a few things in the mean time. He should be sending it back late this week. He said he was having issues formatting the SSD, so I'll flash it from the SD card once I get it back. I had some issues with it as well before I sent everything to him, but it was only because the SSD hadn't been formatted yet so it wasn't visible by the computer. I had bought a second SSD and flashed that one with the image I had set up to see how fast it boots, but didn't get it flashed until after I'd already sent the Pi to him. Even if it was faster than what Mike has, I would still have to figure out how to add all the other controls like turning the UPS off, soft shutdown of the Pi, etc.

I made the mount for the screen and got it pretty well finished tonight. I made the top two brackets too tall so now I have to space them out some because they were pushing the top of the center piece outward and creating a gap. I made the first three brackets and was still trying to get the hood to fit like stock, but once I made the fourth bracket for where there were no mounting provisions, it actually pulled the bottom of the hood inward and it fit much better, but inward a bit too much. I ended up shimming it out a little with a thick washer and now the hood fits really well.

I sanded off the lines but I still need to finish sanding the whole thing and paint it, then it'll be ready for install.

I redesigned the gauges a bit more, creating an image for the background and adding a little drawing of the top of an FD to add tire pressures next to it like on some OEM gauge displays. I'll post pics once it's finished.

Chris Ludwig remoted in a few weeks ago to look into my boost issue and changed the tune a bit. I still have the problem, but it doesn't seem to be dying when it returns to idle, or at least it hasn't yet. I'm still going to buy another ECU to try out to see if it fixes my issue with a new tune, and possibly a new harness if I have to.

I finally figured out for sure which warning lights are ground and 12v, and unfortunately I don't have enough ground paths so I won't be able to use either the seatbelt light or the rear defrost light. I figure I'll ditch the seatbelt light because I can more easily tell when I'm wearing a seatbelt lol. Plus I'm not even sure if the wiring is good for the light to come on. One interesting note, when I downloaded the pics for the warning lights, most of them ended up being identical to the stock warning lights, which wasn't my original intention but was a nice surprise.

[speedjunkie]

I've had some issues with the display that we're still working through, but I keep hitting huge potholes. A couple of them have been fixed, I think, but then other issues will pop up, or current problems will change a bit. I had replaced the Arduino board in the hub and it fixed an issue with some warning lights, but I may have fried the new board again.

Ugh, and so it goes. But this is the design I settled on, at least for now lol.
20250916_184155 by Eric Jausel, on Flickr