Hello, just recently finished up my homebrew turbo kit on my 2002vvt. .64 ar sr20 knockoff turbo, cast mani, 2.5" dp and rx8 yellows (because the 1000cc i had flowed like ****) Anyway I've been tuning it and all is going well, except for a small "blip" or hesitation under high load. If i dont go full throttle it goes all the way to redline fine, but Full throttle causes a weird stumble, sometimes a pop. Afrs are within a good range generally. New bkr7e gapped to .21" stock coils. It does it in the 3-4500 range, and iirc it did it before being boosted, but I never really really figured it out. Ill attach a log and tune. Id also like some pointers on my spark table and afr table.

keep in mind its on e85 and stock internals.
you can see in the log how the rpm curve is decent until its not lmao, also worth noting the tach jumps back a smidge for a split second when it does this. Old plugs didnt look lean or anything.

 

Just curious, are you tuning using lambda or AFR? The stoich ratio is setup incorrectly for e85 in the tune, but I'm not sure that would cause an issue necessarily since you aren't running flex fuel. I'm confusing myself trying to think through if that would work or not, but I think it would be OK.

The spark table looks reasonable to me. I think it tapers a bit aggressively towards redline but that's just compared to other maps I see on here/online.

Have you tried running a bit more dwell? I ran 3.5 ms on my NB1 and I see you're running 2.6

 

I think so, otherwise it would have some real signs of leaning out under boost at 12 afr rather than whatever afr e85 needs right? Its technically on flexfuel, i just have the one ve tuned for e85 specifically rn but still using flex enrichment, i havent gone back to gasoline since its been turboed so i doubt it would work very good.

and i havent messed with dwell at all, ive heard it can fry coils, and dont know what it means to raise and lower it, so havent touched.

Explain dwell like im 5

also should be noted the coils are somewhat new, and the rx8 yellows i pulled myself from a wrecked rx8

 

Dwell has to do with how long the coils charge before sending the spark to the plug. If you need more of an explanation than that just google it.

Larger dwell = stronger spark but yes, there is such thing as too much.

 

You said "old plugs" I'd throw a new set of BKR7E's in there. They're great plugs, but they don't last long and this is the type of issue you start to see as they're going out.

 

yeah i put a new set of bkr7e in yesterday and gapped them down to .21” problem still persists. Looked into dwell and grasp the concept, going to try higher dwell times and see if it helps.

 

I had a very similar issue on my SpeedyEFI. Turns out the fix for me was adjusting the trigger filter settings. If your trigger filter is set to "off", try "weak" and see what happens. My setup worked best on "medium". It was super odd because I never got any lost sync's to indicate an issue with the CKP or CMP sensors. I tried all the things you're trying with no avail. Worth a shot!