Ls1 surging

Hey guys, just after some insight. I am building a drift car that has a ls1. I took it for a drive just before and while driving straight I have full power then it surges. I also tried to do a drifting donut and the whole time it was continually surging and hopping around. Now it has plenty of fuel and it happens if I go left or right. It has a 300kw tune already loaded. Any help would be great. Thanks in advance

We're going to probably need more information to be able to help. My suggestion would be to make a log file of the issue happening and post that here. What is the ECU?

I will try on the weekend to get a data log for you. It's a factory vy ECU with the 300kw mafless tune

Hey Andre, I finally got some live data. I recorded it on my snapon scanner. I will put the link up this afternoon if you wish to download the program to read the data. I noticed it only revs to 4000rpm when the limiter is 6500rpm. As on which way to go now I am completely lost.

unfortunately i cant select the file as its a .scm file due to snapon scanner. I have screen shoted the RPM, on the left is the list of what i can see. let me know what you want to see and ill do screen shots.

The ecu cuts out at 4000rpm. I went back to my car today to see what it did while in neutral. I have a 6500rpm rev limit and it went all the way to 6300rpm. So neutral shows it revs fine but under load is my issue. Thanks in advance guys.