you can see around the 6:10 mark, the engine cuts off three times. in case you're wondering why my throttle drop as rpm climbs, that's my detune by closing the throttle.

Well a few people shimmed the ESS out a bit to address an occasional dropout issue, not sure how valid it is, but just remembered about it in another thread. You might try it :dunno:

also meant to give you this link the other day in the event you consider using a different pcm as this is the procedure list for programming all the relevant modules

https://www.rx8club.com/series-ii-te...r-list-239807/

i found this documentation about the can bus resistor settings on the Aim solo DL

https://www.aim-sportline.com/downlo...ce_100_eng.pdf

Let us know what you find, should be fairly easy to measure across the two wires

I had the same exact issue after doing an engine replacement. I ended up taken it to someone that I considering a wiring expert (as they do a lot of custom wire harnesses and ECU work). For me it turned out to be a bad ground and fusses that were too big. Hope you figure it out

so i had my nasa championship race this past weekend. got 4 NGK R7420-10 spark plugs the week prior and drove the car on the street a little and everything seems fine, no CEL blink for misfire. at the track, i went out in the first session without the aim plugged in. was getting CEL blink for misfire and still getting some engine cut off. so it's not because of the AIM plugging into the obd2 port i dont think. i then change the aim protocol from generic OBD2 to 09-11 rx8 protocol and plug it back in. i use the 09-11 protocol over the 04-08 because it gives me TPS and AFR data. also switched back to new OEM spark plugs. went out again and still getting CEL blink and random engine cut off.

Why did you change back to OE plugs?

i thought maybe the the misfire was from the NGK R7420-10 but turns out that wasnt the issue either. it was still getting misfire with the oem plugs.

You can run -11 plugs without it breaking up, eventually they just foul from being so cold

i also notice the plug gap on the NGK R7420-10 seems a lot smaller than the oem. wonder if i should regap them.

Gap: .028" (0.7mm)
Gap: .043" (1.1mm) - oem

Run the small gap

Thai, i haven't read the whole thread... but i assume you've logged AFR at the times it's acting up? I have an autometer fuel pressure gauge and all the fittings for RX8, never installed, if you think it would help with your troubleshooting.

i had one cutout at the hillclimb in the middle of 1st gear, once mid corner 2nd gear, and once the other day street driving with the A/C on. when i turned the A/C off, it pulled straight to redline. but i never get the blinking CEL.

i dont think the CEL blink is related to the engine cut off, but i could be wrong. if you look at my race vid, you can see the number below the coolant temp is the lambda value of the stock wideband sensor. it's showing .92 ish on the top end. probably too lean. wonder if engine is cutting out if there's knock? this is the first time i used CAN protocol for 09-11 rx8 on AiM solo DL, so i can log AFR and a few other things. cant log knock with AiM though.

Meh, it can get away with being a lot leaner than that. The eventual issue is side seal abuse.

good to know you can go more lean. when i disassemble the old engine, three of the of the side seals were cracked and one had chunks missing. most of the side seal spring were also broken. engine had 72k street miles when i bought the car and i did a hand full of track events on with. are there any better options for side seals other than oem?

No, but exhaust temp has a lot of influence on that so somewhere down around 0.89 lambda or less than 1650*F exhaust temp is where it needs to be

Over-revving past peak HP is also not good, but you have to choose whether you want to go there and live with the consequences

my rev limit is set at 9300 but i typically shift at 9k, the detune drops power a lot after 9k to lower the average HP calculations. sometimes i do ride it out to 9300 if there's part of a track where i dont want to short shift.

are cryo treated side seals any benificial?

Getting the end clearance right likely matters more imo.

Subscribed, experiencing same issue. Cleaned ground and battery terminal and the problem still remains.

May I ask what's your current tuning software? I saw your post that you are using VersaTune. I also use VersaTune, after I tuned the vehicle and it starts to cut off for a split second then resume.

When the car cuts off the battery light comes on even though the engine is still in gear, which means the altenator is still spinning.
Coolant and oil pressure light will come on as well, just light when the car just started, so I think it might be tuning related, will uninstall Versatune and return the car to stock tomorrow and see how it goes.

Should not be any weak point on the car since I have done almost all the reliability mods and the engine has passing compression.

Temporary conclusion: Could be one or more: Altenator, battery internal short, loose wire, Tuning software (ECU), Main relay.

yes i'm using VersaTuner software. i had thought the possibility of software related, but since i have a ported engine i cant go back to stock map to test that theory. it only seems to do it while on track, it has never done it on street. although i rarely ever drive on street, only once in awhile for testing. when mine happens, it seems to happen multiple times, lie a few seconds apart then it clears up. rpm signal drops completely, on the dash and on AiM logger, even though engine is still spinning. if you have bad alternator, your engine should still be running until the battery gets low on power.

I’ll uninstall it to see if the problem solves itself.

I forget, have you tried disconnecting the AiM?

BTW, by any chance, did you remember what were the lights that came on during engine cut off? If oil and coolant light were on then it is very likely to be the ECU, or versatuner related

yes, at my championship event last week. during the first practice session, i disconnected the aim, and was still getting the same engine cut off. i then tried different protocol with the aim.

i dont remember and never really pay attention because i'm more concern with not crashing on track. does yours happen on track or on street? also mine seems to happen under WOT.