This is a 2005 GTO with a TVS 2300 231/248 cam with -5 overlap, 418 cu in. 11# boost, 2 bar sd, 4l80, E40, Fast 65# injectors, boost referenced return fuel system.
It stumbles off idle every time even when the car is moving, if I am off the gas.
Stumbles at frame 1781,2010,2525,2527,3231, 5268 and a few more in between.
I have attached the tune and the latest log.
Thanks for any ideas.
Last edited by Lakegoat; 04-24-2015 at 05:38 PM.
Don't have a way to view your log or tune at the moment, but just had a few questions. Is this a lean stumble as seen on the wideband? Did you adjust injection timing for your cam and added blower? If not add approximately 22 degrees to your boundary injection timing then restart VE tuning...
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
It is a lean stumble shown on the wideband and felt in the seat of the pants
I upped the primary VE table in the 400 to 1200 rpm range quite a bit, the stumble went away, but now at idle in park I have -20 STFT's. I have been logging the STFT histogram and modifying the VE table. I think the stumble is coming back the more that I work.
The boundary is 520, so I should add 22 to that?
Thanks
OK, went back to the tune that is attached and added 22 degrees to the boundary. It did the same thing as me increasing the ve table. STFT's in idle went to -20 but I think this way is going to be easier to finish the ve table. Also looks like instant mileage is higher.
Any other tips----keep them coming.
Thanks
Just make sure to give it atleast 15 minutes after flashing to get over it's rich after flash condition before tuning VE and I think you'll be OK. The SD operating system conversions seem to be worse for this than the typical MAF setups, so watch out for it.
2010 Vette Stock Bottom LS3 - LS2 APS Twin Turbo Kit, Trick Flow Heads and Custom Cam - 12psi - 714rwhp and 820rwtq / 100hp Nitrous Shot starting at 3000 rpms - 948rwhp and 1044rwtq still on 93
2011 Vette Cam Only Internal Mod in stock LS3 -- YSI @ 18psi - 811rwhp on 93 / 926rwhp on E60 & 1008rwhp with a 50 shot of nitrous all through a 6L80
~Greg Huggins~
Remote Tuning Available at gh[email protected]
Mobile Tuning Available for North Georgia and WNC
Thank you so much for the info.
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