Twin Turbo z06 Lean WOT. Fuel Pump? or Tune? log/tune attached

First off thank you to the community, you have been helping me on this same car for over 2 years, bolt ons first, then custom cam, and now I am full twin turbo.
The car is running fine, starts, cruises etc... all great, I can not get AFR corrected when hammering the throttle.
MODS:
Speed density
Twin turbo on3
Cam 228/248
85# snake eater injectors
stage 1 snow brothers methanol(powered by hobbs switch 1 PSI)
Boost a pump 18v (Powered by Hobbs switch 1 psi)(Stock z06 Pump)
bkr7e spark plugs .28 gap(tried tr6IX iridium gapped 40, same result, very lean on WOT)
everything else is a small add on and should not heavily affect the afr

I see my injector flow ratedropping and figured it was from the boost(it could be that my fuel pump cant keep up), and I dont have a boost referenced regulator to compensate, but I am only pushing 3 lbs of boost, and thought i would be ok for now. I basically raped the VE tables and same result. I dont mind going back to MAF if that will help, I can even tune MAF only, which is probably my next attempt, but I wanted to hear from the experts, what do you think, is it transient fueling, maxxed out VE tables, Weak Fuel Pump etc... thank you in advance.

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u need at least a 2 bar map sensor as the 1 bar wont go very far on boost as it looks to be maxed out so that will also not add fuel as it cant go any higher when SD, also u should fail the maf better as its dosnt look to be done right and ur still showing maf HZ in the log so if it sees HZ it wont fail properly

Thank you for the reply, I do have a 2 bar OS, when you patch the e38 to Speed density, it is then 2 bar(image attached, mine has already been patched), and moves max map to 175 as well as a max maf hz of 15400(with 3 psi of boost i only run 114 kpa). As for failing the maf, you can see in the images attached, i have failed it both ways, high and low, and maxed out dynamic airflow minimum rpm, so it never enables. our IAT and MAF are combined in one unit, hence even if you fail the MAF by having it read too high or too low, the MAF will continue to read, but the ecu will reference VE tables instead of MAF(i still record MAF g/s and hz for HP calculations). I do appreciate the help though, it made me go back through and double check my tune(I added the MAF monitor state, just to triple check it is failed). I have gone more aggressive with ve tuning and it is now making a difference, I will post again if i can get it running right, with the before and after tune. Please keep any suggestions coming, thank you.

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You have changed to the 2 bar OS system but as 07GTS mentioned, have you physically swapped out the stock map sensor for a 2 bar map sensor?

yea the map sensor is still setup as 1 bar, u can use hp calculation when SD also, u can see on the log map is pegged straight line (right where the 1 bar limits) its extremely strange to see a straight line when tuning a variable related to airflow and ur prob going leaner cos boost still climbs but ur map isnt showing it

make sure you have a 2bar or 3bar zr1 map sensor then set the relevant scaling.

your pretty much wasting your time with the stock pumps even with the boost a pump. safe your money and get yourself a fore innovation upgrade & return system.

i very much appreciate the help, i was really wondering why i pegged out at 114 kpa, i was able to tune around it with some heavy changes to the ve table, but i figured this was way too difficult for some reason. I will get a 2 bar map sensor, and then try fine tuning. Again very much appreciated.

yep just clarifying,

1. stock fuel pump- no good , don't rely on it or boost pump IMO
2. You need rising rate regulator, for every 1psi of boost you will lose 1psi of fuel pressure otherwise.
3. I'd also careful about anything that activates at 1psi, it might be too easy to reach 1psi and come on unintentionally

I agree, unfortunately im not ready to drop the fuel tanks in the c6 yet. I wish it was just a fuel pump replacement, but I will have to bypass the current fuel pressure regulator, design/purchase top hat and cannister for dual pumps, install/mount external FPR thats boost referenced, as well as wiring the second pump to a boost relay, and then running an entire return system, with new fuel rails. Soooo i thought id have some fun on the stock pump at 18v for a just a little while. but i agree my fueling issues will catch up to me very soon. thanks again for the help and advice.

Im in Australia so not too many corvettes here, but I helped a mate do the fore innovation dual pump system on his C6 Z06 in a day including wiring. Obv you need a 2 post hoist to do it, but it's not anything technically difficult.

Pain in the ass to do, absolutely but not hard.

Best to have the fuel system side sorted out first then trying fight the stock limitations straight up.

Hint, use the original evap line as the return & you don't need to run any new lines.

the original evap as the return line, that is beautiful my friend, I never thought of that, but it technically runs to the fuel tank, and the return line doesn't have to be huge, that is awesome advice. I took everyone's advice, got the 2 bar map and the car is finally on for tuning, thank you to everyone again.

Have you taken a look at your PE and BE

i have them stepping down as expected now, and the afr is almost perfect. for PE i have about 12.7 commanded between 60-95 kpa, and then BE from 95 and up around 11.6. thank you for the suggestion, I have attached a log including the wot pull and im always up for suggestions, please let me know if you have any other advice, like how to get rid of that lean spike when i first roll onto the gas, thank you.

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post your latest tune

i have many latest tunes, here is the current one im using, i backed BE down to 90 kpa and have it targeting .77 lambda, I live in denver, Baro is normally 87 so by 90 kpa im in boost. i also disabled closed loop for constant open loop in SD. Generally i tune closed loop SD but i burnt an O2 sensor wire, and I will be using this until my new O2 extensions get in. i have it set to purge during openloop which is abnormal for my tune, but needed while in constant open loop., Ive also richened PE after 4k rpms just to ensure I dont ever go lean in boost. I have also set my idle adaptive spark settings back to normal for stealth driving, you cant even hear my cam, normally i would have more aggressive idle adaptive spark for that lopey cam sound. So take it for what its worth, im testing a few different things, its not a final tune and will probably be greatly altered after i get my o2 extensions, but if you have any questions on it feel free to ask.

I am also finalizing the WOT tune, once its on and I have the log, I will post the tune and the VCM log so you can see what my car does power wise, airflow wise, afr, manifold pressure, coolant temp, manifold temp, etc... if all works out right, Ill be about 120-30 degrees manifold temp, 90-150 degrees intake air temp during WOT, 190ish coolant temp, 130ish map with 6lbs of boost, and approximately 700 hp at 6400 rpms moving 550 g/s of air. After this I will work the tune towards 12 lbs with my boost controller, but I have found that the c6z on 6lbs smokes everything but 1% of cars in denver, and I would like this to run more than a year.

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