Andy R

Could someone provide me some feedback on pro's/con's of fuel cell sizes for competing in SCCA/NASA type road track events.

I am looking at a ATL 10 Gallon sports cell and wondering if there were any down sides to the smaller capacity. The setup is going to include an internal/external (not sure yet) surge tank with a surge pump and main pump.

Andy R

anyone?

Bakeoff

Obviously, if you're doing longer wheel to wheel events, you could benefit from a larger fuel cell. But in all honesty, what's the weight savings on a smaller one? Maybe a couple pounds? If you're running into issues with the physical size, just try to get as close to the stock size as you can. But you shouldn't need more than that in most applications.
As long as you have the foam anti-sloshing deally thing (technical terms) in there, the larger cells shouldn't give you any issues that a smaller cell wouldn't.

Andy R

I like the size of the ATL 10 gallon (24" long x 12.5" wide x 10.13" deep). As soon as you jump to 12 or 15 the width is up near 18". I'm trying to fit this near the stock location of a 2g Honda CRX. Max width I can have based on location between roll cage is about 18", but going with the 12.5 wide cell would allow me to lower it another 3-4" (thus lowering CG). I know they will make any custom bladder/container, but its out of my price range.

I'm not too worried about fuel starvation due to sloshing since these units are specifically designed for road racing applications with fuel traps and my use of a surge tank.

Thanks

kb58

Actually, they aren't. The trap-door surge tank is an extra $200 or so.

Also, the foam does little to prevent slosh. It's main purpose is preventing fuel atomization in the event of a crash.

I have the 10-gal unit in my Mini, at anything below half-full, I can hear the pumps sucking air during cornering. It's not a problem if you have an accumulator, but it' something to be aware of.

Andy R

Thanks for the responce, nice to know someone else has one out there. Did you choose yours based on space or capacity? Wtih the setup I have (b16a, turbo ~300hp) I will probably be consuming between 25-40% more fuel than your H22. On track days, do you only fill to calculated capacity based on experience of how much a track and X # of laps uses (+ margin) or do you fill full? Appox how much fuel does a single event consume?

BTW, I love your car thinking about doing a front engine f20c (S2000) into a Austin Healy Sprite type vehicle.

kb58

Thanks. I bought it because I wanted the safety, but also because of the shape. I have mine where a "normal" transmission would be, just ahead of the shifter.

I fill it before the event and (so far) have yet to empty it, though like I said, I refill it once I hear the pumps start knocking. It doesn't weight that much full so I always fill it completely in the morning. For a trackday, filling it 2-3 times during the day is easy. It's day-to-day street driving that stopping at the gas station every couple days gets to be a drag. No, for the track I'd use as small a cell as you can, along with an accumulator.

[edit] I should add that Fuel Safe has an in-tank accumulator with trap-doors AND a pump. Very sweet, but expensive. However, it's an all-in-one solution that I recommend.

About your car project, that would be a blast, as long as you can wedge the F20C in there. You'll want to redesign the suspension though, and I know just the book for you (hint, hint, see sig.)

Andy R

It seams Fuel Safe and ATL seam to be very similar in their product line. ATL also has available what they call the "Black Box" in-tank surge tank kit that comes with pump and filter.

I'd be interested in seeing some pictures of your tank mounted if you wouldn't mind.

Thanks

rex_boy

I don't know is if its a b16 turbo you might burn a lot of fuel. Isn't the CRX SI a 12 gallon tank and I barely had enough to finish nationals (40min) race with a tad over 3/4 full with b18. Next year I will run a full tank not just to have enough but because of fuel starvation.

Andy R

Thanks Paul, i'll take that into consideration. I'm going to work on the cage some more tonight and i'll try to get some better measurements to see if I can fit a larger tank in there. Personally, 12-15 gallons sounds nice, but just haven't found the right dimensions to make it work.

Part of the issue with the crx is the parking brake cables running through the area where I have cut out the sheet metal above the stock tank location and am mounting the fuel cell. With the 12" wide cell, I can avoid the cables and mount the cell a bit lower. Using the wider 12/15 gallon cells pushing the tank into this spot and require raising the cell about 3". I imagine I could probably work a solution with modifying the path the p-brake cables run. Another option is to move the cell to the spare tire area and use a larger 12/15g. I guess i'll have to do some visualizing tonight.

Bakeoff

you may want to look into using 2G teg ebrake cables, assuming you have rear discs. Otherwise 88-91 sedan cables might to the trick... There's an option that will work. Just gotta find it.