Before going to last Wednesday's autocross, I drove the car around my local area for about 150 miles. Didn't have any issues. At last Wednesday's event, found 2 issues with the fuel tank - the brand new cap O-ring split and started leaking - that was the minor issue. The other major issue was the vent was leaking during and after each run. I made changes to the vent line with the new tank and that didn't work causing a siphon effect. To fix this, I made a vent can similar to what you can buy (I would have bought one but there was no time for shipping and installation before Saturday morning).
Here is what I fabricated and had a local welding shop tig weld together. It's a 3" round piece of stainless exhaust pipe, 4 inches tall. One fitting is welded flush to the floor of the can and the tube goes up into the can about 1/4" from the top.
It's installed on the highest part of the truck floor above the rear end:
The vent line from the tank goes to the fitting flush to the floor of the can and the other one goes to vent - It's a 3/8 tube that runs between the tank and trunk floor to the vent that's behind the rear plate just above the fuel cap. I used this vent:
https://www.summitracing.com/parts/tnk-vvr
This setup worked great and didn't leak a drop all weekend.
Here is an image posted on the DriveAutoX FB page - headed to the finish line on Sunday:
