Lots of pics from others' threads, but here is my tunnel with Thermo Tec adhesive fiberglass/reflective matting. I put it on the OEM heat shield that bolts on near the cat, too.

Attachment 177358

Helped a lot for 1hr+ track stints, but I still got my headers ceramic coated for my new engine.

​ I made a really cool shield, sandwiched two layers of heat wrap between two pieces of mirror polished stainless. Looks great, but haven't installed. No excuse besides racing dirtbikes, golf, hiking with the dog, camping, and a few autocross events.
No real idea on how to mount it yet, either.

https://cimg6.ibsrv.net/gimg/www.mia...aa18525634.jpg

https://cimg3.ibsrv.net/gimg/www.mia...42ba5f7136.jpg

You can hold it in your hand while blasting it with a propane torch.

I did it and melted a cat in a few thousands miles. I shield it now to keep heat out of car, but let air flow around it on the bottom.

New problem with tune. Well, old problem, finally bugs me enough.

I have tuned all of the boost area on the fuel map. I have tuned it in incremental boost pressues. It's pretty dialed in, and I can keep the o2 within -.4 to +0 of the AFR table, at all boost levals, all rpm.

With the map like this, if I'm cruising at 4k and go WOT, I trigger the afr safety. Why?
Afr safety is .3 of afr in this trouble area.
Lots of fuel added with AE.
Can only fix it by running the 3.5~4.5 k. Rpm fuel cells REALLY rich. Like a whole point more rich than I want.

You haz ideas?

Can you post log with PW when problem occurs?

I will try to do that tonight.

If the higher cells use lower AFR, then MS will show AFR differential (error) the moment the MAP increases, but before the enriched exhaust reaches the O2 sensor.

Picture: running 60 kPa target AFR of 15.0. A cylinder fires. Punch it and kPa goes to 100, and target is 13.0. Next injection is adequate and engine fires. However, the exhaust gas that is now passing by the O2 sensor was from the previous, 60kPa cycles. AFR safety is triggered because differential is 2.0.

You should likely notice that the actual, measured AFR never goes high, there is only a time delay during which only the differential goes high. If you dump a bunch of fuel, I suspect you will see a dip in AFR, after the rise in AFR differential (if AFR safety doesn't cut first).

Hence, use a time delay so you don't get an AFR triggered spark or fuel cut, only a momentary warning.

EDIT: In other words, the problem can be that: the AFR does not go high, but the AFR TARGET moves low. Proof can be had by temporarily setting AFR at 60 and 100kPa to 13 and punching. If there is a lack of AE, then AFR will increase and you will still have the AFR ERROR. If it is what I suggest, AFR will remain at 13.0, and the issue is target movement, a false issue.

This makes complete sense, and is exactly what I think is going on. Thanks for the insight. I'll log tomorrow and report back.

As i was getting the afr situation figured out, anew problem developed! sputtering at 4k. sounds like a spark cut, But I didn't change any of that. Tested the spark output, from 600 rpm to 10k all coils fire great. check this log, see anything?

Attachment 177549

Looks like misfire in boost. What plugs and what gap? What ignition coils?

Same plugs I've always had. Miata turbo a proved ngk copper @.025. Not sure on number. Need to check.
Coils are 585's. I have put somewhere around 4,000 miles on this set up. Zero issue like this til today. Plugs look great, coils test great.

No change to the tune. Also not boost sensitive, just rpm.

Check the connection at the cas? My friend's car would do this, turned out to be a bad crimp in the repaired harness (PO was an idiot....).

UPDATE on misfire :

Replaced the 585's With a new set, replaced the cam angle sensor. Still misses at 4k under boost. Continues to misfire until I let off and fall below 4k. Going to check plug wires now. Not really sure what to check for besides resistance.

Logs do not show any lost signals.

Next time you are driving and logging, hit the space bar when you get a miss, then post the log. So that was we know where exactly in the log to look for the miss.

In the log I posted up there^^ it's right at about 4200 rpm. When the rpm suddenly gets all erratic. You can see the tps stays at 100, but the rpm rises and falls by a couple 100 but continues to climb slowly.

I'll get another one though.

MISFIRE SOLVED !

It was a plug wire boot. one of the boots on the coil end, must have had a microscopic hole. I had the hood up, in the dark (don't ask), and noticed a giant spark every time the engine had a misfire..
replaced the boot with a new one, problem solved.


Now i need more help. closed loop idle. I still cant get it to do anything other than stall. The engine doesn't respond to ANY changes in the closed loop settings. I am clearly fucking something up. If you open the tune, I am back on open loop, because it works. so if you apply closed loop, does anything look screwey?

HALP ME?

Attachment 177614

Glad to see it was something simple for the missfire!

For closed loop idle, that is my current brick wall. No idea how to work the darn thing... You can get a reaaaaly nice idle playing with open loop if you take the time. I sit at 1100rpm with everything off, 800ish with everything on, and 1500 when the AC is on. No stalls or anything. Idles rock steady.

Check this shit bitches...fun stuff. The inside of a modern 250cc motorcycle engine. Five titanium valves, two cams, one cylinder, 37hp.

https://cimg4.ibsrv.net/gimg/www.mia...ca2828f6b3.png

https://cimg6.ibsrv.net/gimg/www.mia...73c0f5d84c.png

More important then motorcycles, hows that closed loop idle going?

Crummy. It worked pretty good the first time I fired it up. Then I drove it and it constantly stalled. I tried raising the low number on the idle valve, but that just made it idle a little higher initially, then the idle would just droop until it died.
Tried a cold start this morning. It just fired up, ran for about 3 seconds, then died. Tried that a few times, then just turned open loop back on. Smooth, 14.5 but at 900 rpm, as always.

Just not sure what I should be changing to manipulate the closed loop.