Sputters on the the right sweepers

[pdawg]

Went autoxing last weekend. It was great. We raced the road course at Nashville Super Speedway. As per normal I got a late start and decided that half a tank of gas would be plenty. So by the time I got there I was sitting somewhere between A quarter and half a tank of gas. Every run on the right hand sweeper the car sputtered like it was running out of gas. Is this because all the gas was moving away from the pickup point in the tank? There were three spots on the course that it did this every run. Other than that it is running great.
Here is a video. Listen after the first right hand sweeper. Sorry about the language.
http://www.youtube.com/watch?v=BUaLwmwiLdU

[TGX4776]

I was expecting some glorious cursing. Oh well. Sorry I can't help you with your problem

[pdawg]

I was expecting some glorious cursing. Oh well. Sorry I can't help you with your problem
This was my third run, the sixth and seventh are much worse.

[ScaryFatKidGT]

Walbro 255, New fuel filter and a foam filed fuel tank? lol

[scoobydorift]

Check your intake hoses post MAF, make sure the clamps are all tight and there are no leaks. I had this problem on my EJ20G engine, was just a loose hose clamp. Every time you turn right, the engine shifts to the left and pulls on the intake tubing a bit, sometimes enough to create a leak post MAF and you get hesitation issues.

[ouch1011]

Given that you were running low-ish on gas, I'd say that was your problem. My old Probe had the same problem at 1/4 tank or less. I've never pulled a Subaru gas tank but some tanks have baffles around the fuel pump to help avoid this problem, while others don't and pretty much allow the gas to go wherever it wants to.

That's why a lot of race fuel cells are filled with foam, keeps the gas from sloshing around, which can not only cause this problem, but the weight transfer of sloshing fuel can even unbalance certain very lightweight race cars.