Ya, this is an odd one, but this is the best forum for it.
Quick run down... I have an originally carb car. Can't find a clean Si tank anywhere and had to get my car mobile again, so I had mine dipped and coated then came up with this design.
I will try to describe it as best I can. Will also draw up a pic later if I need to help get it across better.

The fuel pump is rail mount so the fuel pickup in the tank is a simple pipe down + sock. My thought is to add a return line along side the pickup with bulkhead fittings and build a mini-cage that attaches to those two pipes (that lifts out with the drop in unit) and so dumps the return next to/near the pickup inside the cage helping fill the baffle during hard turns and accel.
My limit at this point is how to do the cage. Completely enclosed sides? Small fill holes? Really, I'm not sure what is the best. The car is going for lap days/road racing so this is rather critical.

 

Ive actually seen people use extremely non dense foam with pretty good success. I cant remember what it's original purpose was that it was used for but i'll try to get in touch with the guy. Or I would assume they make foam specifically for this reason, works quite well

 

Like what comes in a fuel cell? I've heard of it, but I'd rather not reduce my tank capacity too much. The car will have to be driven around highway to tracks around the state.

 

I doesnt really reduce your capacity very much. Like I said it's not very dense at all. But it's just a suggestion

 

Well, I'll do some digging. I'm a bit pessimistic about how much it could work with a completely baffleless tank.

Edit, seems lots of it are sold as blocks. Maybe I can do the return like I was going to and carve a piece into a cylinder to encircle them rather than build some exotic metal piece.

 

They guy i've talked to runs it on circle dirt track so i'm sure it would work very well (His are baffleless as well.

 

Gawd, I wish I had taken some pictures of the 89 Civic tank I baffled back in 2005. It would make it so much easier to explain this. Basically I cut open the top of the tank, and made the OEM baffle in the bottom of the tank that surrounded the fuel pump (this was only about 1" high on the sides) extend right to the top of the tank (about 3/4" from the top). At the bottom of the baffle, on both sides I made 2 trap doors that were about 1" high by 2" wide that were placed vertical, and attached to the inside of the baffle area using some small hardware store hinges so that they would swing open at the bottom towards the inside of the baffled area.

When the car was cornering, the trap door on the outside of the corner (baffle) would close from the G force and the fuel pushing against it, and the other one would open. This would permit the baffled area to get filled by any fuel left in the tank that came close to the trap door area, but prevent the fuel that was pushing against the other side of the baffle from exiting, since the "door was closed" (pun intended!).

The fuel pump and the fuel return were both contained inside the baffle area, so fuel excess returning from the fuel pressure regulator would help to keep this full. I know you said your fuel pump is rail mounted, but that shouldn't make any difference here. You just need to mount your pick up sock and return in the same area.

 

ok, those blocks will work and it will give me a cheap proof of concept. Getting some good shape ideas as well.
Thanks for reminding me of the foam. But that means no work for you welder peoples .

 

be careful what kind of foam you get. gas can break it down after some time.

 

well, I dunno how to go about that. There are multiple brands on summit, but no clue of quality.