Pontiac G8 Gt with 6L80

[speedycop]

Just picked this car up, bought from an older fellow that really had no clue to what work was done to the car other than what he could sort of remember, "stage 1 cam and lifters (unknown), intake, lt headers, high flow cats (kooks). The car is pretty quick but hunts/surges while cruising or maintaining speed. Applying the brakes doesnt seem to have an affect. I did a few wot pulls with it and it seems to either limit its self by cutting fuel or like a traction control kill, im not sure. It feels like there is a little bit highter stall speed converter in it as well. Anybody willing to look at this tune and see what i need to adjust? I know its not a stock tune, i just named it so that i could find it later. Also, I know I'll need to attach a log, lap top was dying. I'll get one asap.

[TheMechanic]

Good grief. Where do I start. You got your PE set to start at 2,500 rpm 11.49 AFR.
Here is you MAF. Is this the area you are having the issue?

Screenshot 2025-02-14 180643.jpg

Dynamic air disabled.
Did you change the TB? The scalar is not stock. Not even close.
Oh and no changes to the trans even though RPM limit is set to 6,700. You could set it to 6,300 and it would be the same unless you do a trans mod/tune

[speedycop]

i havent touched anything, got the car home after work and took it down the street. Didnt feel right so with what battery i had left i pulled the file and made the post.

[speedycop]

actually I dont think i ever got higher than 5500 rpm. like i said, i just got the car home and made a couple short wot pulls. I could tell something was off so pulled the file with the battery i had left on the laptop. But cruising at 50-55 mph it was hunting/surging every 5-8 seconds almost like the tc was unlocking and locking but I rode the brake slightly while maintaining speed and it continued.

[TheMechanic]

So you are saying this is a stock tune? No mods?

[edcmat-l1]

That's a lot of PE for a normally aspirated engine. Might wanna back that down some.

Need a data log with some trans pids to see what's going on there. Doesn't look terrible overall.

[speedycop]

So you are saying this is a stock tune? No mods?

No, I named it stock out of habit when I saved it. Laptop was dying and it was the first time I had ever connected to the car. I dont know who tuned it, Im assuming someone local to Hampton VA. I just bought the car from an older man that apparently just gave a shop money until they told him to stop. He had no clue what cam is in the engine other than "stage 1" and LS7 lifters. Its got long tubes and full exhaust (high flow cats and an open intake. Poor guy didnt know what a stall converter is but it sure feels like its got one at least a litter looser than stock.

[speedycop]

That's a lot of PE for a normally aspirated engine. Might wanna back that down some.

Need a data log with some trans pids to see what's going on there. Doesn't look terrible overall.

I'll go log it as soon as I get home. What would you like to see in it?

[speedycop]

So you are saying this is a stock tune? No mods?

I made a few quick tweaks, not optimal but made it a little better. I did not change anything in the trans, seems to fall on its face between upshifts and on downshift