Noob Help with LS2 GTO w/Cam Bucking

[MrCln509]

Hello, I'm new to the HPTuners world and while I have started to read through the mountains of posts, however I am getting really frustrated with the bucking and surging in my goat. It starts easily cold or warm and idles pretty well, although it seems to idle at about 1100 rpm when warm. The most aggravating issue is the bucking I get which is worse when it is cold. It is most pronounced between 1000-2200 rpm although I can feel it lessen as the rpms climb. The bucking is especially bad between 1000-1500 RPMs. If I push the clutch it will immediately stop bucking and the engine drops into a very stable idle. At heavy throttle/wot it smooths out. Have attached my tune file and a log. Any pointers at were to start would be appreciated!

I have 2006 M6 GTO. I have the following mods:

Vararam Intake
LS2 Ported Intake Plenum
JBA Shorty Headers and catted mids
Magnaflow 2.5" Catback
Underdrive Pulley
FTI (Ed Curtis) Streetsweeper Cam - Specs below


Intake Exhaust
Valve Adjustment: .000” .000”
Lobe Lift: .361” .353”
Gross Valve Lift 1.70 Ratio: .614” .600”

Duration @ .050” Tappet Lift: 228* 234*

Lobe Separation: 112*

Recommended Intake Centerline: 109*

Specs at 109 Degree Intake Centerline:
Valve Timing at Open Close
.050” Tappet Lift: Intake: 5* BTDC 43* ABDC
Exhaust: 52* BBDC 2* ATDC

[DSteck]

Wow. That cam should not be that bad.

I'll try to tweak your file a bit tomorrow. Off the cuff, you can...

1. Retard spark timing to lower engine torque, forcing the engine into a higher manifold vacuum to combat reversion.
2. Run extra fuel in the bucking area.
3. Delay injection timing and hope you get lucky enough to blast the plug with a rich pocket. Good luck on that one. Lol.

[MrCln509]

Hey thanks a lot for taking a look. I am very interested to start learning more about how to tune these engines. If there is any additional logs or information you need, don't hesitate to ask!

[MrCln509]

Also, just as a note, I seem to be able to smell fuel when it is warming up, it lessens greatly after it is up to operating temp.

[DSteck]

You're probably smelling hydrocarbons as a result of the advanced injection timin during cooler ECTs. Basically fuel is being sprayed when both valves are open.