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A neurotic over-engineer does a K24Z swap

Old Apr 10, 2026 | 12:12 AM
  #501  
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I redid the shelf I had put at the front of the trailer for the last event - now I have two shelves to hold crap. I also moved the clothes hanging rod to a better location. I’m liking the upgrades.

I packed the wiper arms, hopefully this helps keep serious rain away. I also washed the car (rare) and scrubbed the windshield before applying a couple new coats of RainX. I ran out of energy before I got the inside coated with FogX.
Old Apr 10, 2026 | 11:10 AM
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Originally Posted by Z_WAAAAAZ
You oughtta just go full Datsun with the mirrors at this point haha.
I distinctly enjoy the largeness of the Miata mirrors, so all the retro "bullet" style ones are out. Even having moved the mirror a couple of feet, I'm going to count the number of people who notice it this weekend. It's kinda subtle. Kinda.


Originally Posted by Z_WAAAAAZ
Have fun sliding around this weekend! Still can't wait to come up north and rip an event with you guys over summer.
DO EET! We'll have fun. I woke up to audible rain this morning and a pretty decently strong band came through here over the last hour. I may be using my Dirtfish skills more than I expected. Which reminds me, I should get some plastic sheet to cover the seat between sessions... and other Home Depot racing things...
Old Apr 10, 2026 | 11:20 AM
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If you ever need to wire the windshield wiper motor in a hurry:

Tie Blue/Red to 12v to get high speed, pulls 3-3.5A without arms
Tie Blue/White to 12v to get low speed, pulls 2.5-3A without arms

****, I forgot to do some measurements/tests, I take this with a grain of salt until I edit it. I want this diagram/info somewhere I can find it easily this weekend.



Old Apr 10, 2026 | 09:21 PM
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Originally Posted by thebeerbaron
DO EET! We'll have fun. I woke up to audible rain this morning and a pretty decently strong band came through here over the last hour. I may be using my Dirtfish skills more than I expected. Which reminds me, I should get some plastic sheet to cover the seat between sessions... and other Home Depot racing things...
I ran the test day today. It was dry when I got there at 7:30, but about 8:30 the heavens opened. Dumped a ton of rain for 15 minutes then slowed down, but kept raining until about 11. Did a couple sessions in the wet.

Dried out after lunch, did a couple more sessions, then decided I was done for the day. Just as I came in, the heavens opened again. About 45 minutes after that the lightning started and they shut everything down for corner worker safety reasons.

Current forecast suggests it'll probably be dry Saturday morning (for our qualifying), but rain all afternoon (during the race), and then more thunderstorms on Sunday. I brought the rains, but they're used and it remains to be seen if they've got 3 races left in them.

--Ian
Old Apr 12, 2026 | 10:41 AM
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I felt like @codrus needed more cowbell, so I added some to his tow vehicle while he was racing yesterday. Let’s see if he notices. (I will tell him before the end of the day so that he doesn’t drive 3 hours home with it) Cow bell is from DirtFish, because I blame him for instigating my investment in that course. It’s paid huge dividends this weekend. None of my sessions had actual rain coming down (yet), but the track has been slippery and variable. It’s been a lot of fun feeling the car slide a bit and learn this whole “slip angle” thing. FUN!
Old Apr 12, 2026 | 12:18 PM
  #506  
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Originally Posted by thebeerbaron

I felt like @codrus needed more cowbell, so I added some to his tow vehicle while he was racing yesterday. Let’s see if he notices. (I will tell him before the end of the day so that he doesn’t drive 3 hours home with it) Cow bell is from DirtFish, because I blame him for instigating my investment in that course. It’s paid huge dividends this weekend. None of my sessions had actual rain coming down (yet), but the track has been slippery and variable. It’s been a lot of fun feeling the car slide a bit and learn this whole “slip angle” thing. FUN!
That is a great prank. I am so going to do that to some people at my next race.
Old Apr 12, 2026 | 12:37 PM
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Originally Posted by rb92673
That is a great prank. I am so going to do that to some people at my next race.
Sadly, he did not notice it on his drive to/from the hotel. But it was fun anyhow.
Old Apr 12, 2026 | 10:57 PM
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Originally Posted by thebeerbaron
Sadly, he did not notice it on his drive to/from the hotel. But it was fun anyhow.
I did not. I was super tired when going to the track, but reasonably refreshed in the morning. Guess the powerstroke drowned it out.

--Ian
Old Apr 13, 2026 | 05:44 PM
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There will be updates, but spread across a couple different threads, I think:

1) The engine still won't rev out to redline, except while standing still in the paddock. I will re-re-re-re-visit the logs and share logs+map in the Haltech forum.
2) The dash worked well, mostly. I need to get the gear display correct because right now it's all screwy and it definitely would have been useful a few times. I did at least two laps entirely in 6th, thinking I was in 4th and wondering why the engine felt like a dog. I also want to re-tune the ranges for the temps I actually see, rather than the ones I predicted. I need to go dive into logs for that data. Also, the oil pressure one was too busy.
3) The trans temp gauge was very useful. I had a little trouble going into 5th on Saturday at the end of a hot session and I was able to quickly note that it was about 200F. Yet on Sunday, it did reach almost 200F and was fine. So there's something there, but I'm not sure what yet.

Somehow, our group lucked out and only one session had active rain. The rest of the time the track was pretty variable - damp and cool and slippery, almost dry but slippery, and hot and dry. I did a LOT of playing around with slip angle and sliding the car. Dirtfish REALLY helped out with feeling confident enough doing this. I also had one moment where by the time I said "oh ****!" I had already corrected and was moving on. That felt amazing.

For y'all's enjoyment though, here's me taking a Spec Miata line at the exit of T1. Rally skills applied at the track!

Old Apr 13, 2026 | 06:48 PM
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Love how it's completely visible where mistakes have been made on that corner exit haha. Nice save! I wanna see the whole lap.

Regarding trans temp, I think I remember Emilio saying the 6 speeds generally don't start having shifting issues unti 260 or 280*F? I can't remember what thread it was in, but the info is on here. I was tracking trans temp data with the 6 speed in my NA for a bit, but I had a cooler and never saw it peak over 190* on track, so no real datapoints from back then.
Old Apr 13, 2026 | 09:41 PM
  #511  
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Dammit, I think I found the culprit by comparing my current map to the one from a year ago.

Cam Control -> Intake - Long Term Trim

One year ago (before windage tray self-destruction, before bad crank sensor):




Today:


Yeah, I bet that has something to do with it...

That was so easy to find with a fresh brain and the comfort of home.
Old Apr 14, 2026 | 12:36 AM
  #512  
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Originally Posted by Z_WAAAAAZ
Love how it's completely visible where mistakes have been made on that corner exit haha. Nice save! I wanna see the whole lap.

Regarding trans temp, I think I remember Emilio saying the 6 speeds generally don't start having shifting issues unti 260 or 280*F? I can't remember what thread it was in, but the info is on here. I was tracking trans temp data with the 6 speed in my NA for a bit, but I had a cooler and never saw it peak over 190* on track, so no real datapoints from back then.
I never tracked temperatures in mine, but I'm pretty sure I could have prevented my 6-speed failure with a cooler (input shaft bearing). that was 340+ at the wheels, though.

--Ian
Old Apr 14, 2026 | 01:03 AM
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I went ahead and bought some pictures by Got Blue Milk. I like that they're of a wet/dramatically-lit weekend. I really enjoy this one.


Old Apr 14, 2026 | 12:00 PM
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Way out there thought from pre-coffee morning brain - if I had excess time and money, how funny would it be to make this a mullet car? Make the nose look like a Honda and leave the rear as a Mazda....
Old Apr 14, 2026 | 05:20 PM
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Originally Posted by thebeerbaron
I went ahead and bought some pictures by Got Blue Milk. I like that they're of a wet/dramatically-lit weekend. I really enjoy this one.
Spec-tacular license plate. Never noticed that before.
Old Apr 17, 2026 | 05:12 PM
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I went ahead and cleared the LTT on the intake cam control and double-checked the base timing. I was off by a degree on base timing, so I fixed that and then took it for a quick blast "in Mexico". I was able to hit the limiter in 1st and 2nd.

Hoping that has actually resolved the issue.

I asked Claude.ai for some help this week and thought I'd share the semi-useful results:

Haltech asks for "MPH per 1000rpm" to calculate gearing. Attached is an HTML file that will do that calculation for you based on your tire size, gear ratios, and rear end.

For my odd combination of 6-speed + 4.1 on 225/45/15, that results in:

1st: 4.43
2nd: 7.35
3rd: 10.13
4th: 13.26
5th: 16.67
6th: 19.77

The Fluidampr for the K20/K24 has four timing marks on it, but no documentation to tell you what those marks mean. I tried to chat with their support folks, but got no response. So I had Claude create a little template that I could hold up to the damper and identify the markings. This assumes that the first big mark is TDC, of course. I'll save you the trouble and tell you that per my measurements, the marks are TDC, 6, 8, and 10 BTDC. Yay.

I could have looked up or derived these formulas myself, but that would have required much overthinking and triple-checking of math. I did catch Claude having different results in the printed table it provided vs the javascript widget, but overall I felt the results were trustworthy. And it showed its math, so I could double-check if necessary. It's good enough for my sanity and saved me from having to wait for Fluidampr to respond to my support request.

All hail our sometimes-erroneous AI overlords.
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