VE tuning help with 3 Bar SD and Turbo

I have read and studied several tutorials online showing how to tune the VE table to dial in AFR.

I had a 5.3L 862 heads and a LS9 cam running 7 to 8psi boost and had dialed in the AFR to give me .75 to .8 Lambda under full throttle. VE in the 315 KPa area was 190. 19degrees timing. Car runs 6.0's in 1/8th.

I changed the cam to a LJMS Stage 3 Turbo and BTR .660" springs and the tune changed to .9 Lambda under full throttle. What was weird was the boost shot up to 13 PSI but the car ran a 6.0 again.

Am I to take the .9 Lambda and divide it by .75 to get the percent increase to adjust my VE table? It seems to be way off considering I just changed the Cam, (+20%)

Thanks,
Greg

Use your wideband, that's why you have one.

All of those tutorials or video's should have at least said something about using the wideband to create an AFR or Lambda error against the commanded AFR or Lambda to show you exactly where you need to make yours changes. If they didn't mention that, they were terrible things to follow.

I have a guide on VE tuning. Not sure if that's the one you watched, but I definitely mention how to set this up, and how to use your error percent to make the changes. I don't recommend making guesses as to how much or little a certain part changed the VE. The initial 15% added at the beginning is only for safety purposes, in order to tune the table, not a set it and forget it kind of thing. Cams absolutely change the VE, and effective/boost compression, and a lot of other factors when it comes to airflow. VE table must be completely retuned when you swap a cam out, and the amount of total VE change depends on how much different that cam is over the previous one. It's literally the point in doing a cam swap is it not? To change the VE?

Also, how are you on the 315 row with 9 PSI? Even at the 13 you mentioned, you should still be under 2 bar, unless you're at like 10,000 feet or something. And even then hitting the 315 row would be something I'd like to see lol. It would be a lot more than 3 bar at that point (technically), at 10k. Maybe I am reading it wrong though, and you are just referencing it, but still, makes me wonder.

Forgot to include the link... lol. Added it to my sig as well like I have it over on tech. I don't check in over here as much as I should... Here's the link in case the sig doesn't work.

https://forum.hptuners.com/showthrea...430#post576430

What I was meaning to post was the VE table increases linearly to 190 @ 315. I'm familiar with VE tuning but was suspicious at the need for a 20% change. This is a drag car with no way to drive around all day populating cells. The car was tuned for a .75 to .8 lambda at 8psi and now I'm getting .9 lambda at 13psi. I'm guessing the lean condition is causing more boost?

Thanks for the link. I will post a follow-up after this weekends race.

Or it could be you are out of fuel injector or fuel pressure is dropping.

Follow up to this issue. I am running Bosch 0280158830 2200cc injectors. These injectors are heating up from engine heat and they change how much fuel is injected. I found that I was running on basically 6 cylinders. The injectors would get hot and stick closed, open, or be very restricted. Be aware these Bosch 2200cc may cause you problems like they did me.

maybe not authentic bosch injectors, I've heard there are fake copies of everything

Aren't those the LNG/LPG(?) injectors that are known to go weird when you try to put hot (relative to what they're designed for) liquid gasoline through them?