Show me your small fuel cell!

[OneWayOut]

I am considering replacing my leaking 5 gallon fuel bladder with something smaller. Something off the shelf would be ideal, or I suppose I could have someone custom-make a smaller bladder and cover. A dipstick, sender, or sight tube for fuel level would also be a nice addition, as I currently have none of the above.

The general consensus seems to be that 1-3 gallons is plenty for a full day of autocross. A number of people seem to use drag racing or go-kart fuel cells with no separate bladder and no foam, and that would certainly cut down on the costs as well.

Any other ideas? What do you use?

[rickb99]

.....The general consensus seems to be that 1-3 gallons is plenty for a full day of autocross......

Really? What kind of car are you running? A 2.0 Liter FC will consume about 4.5 gallons in 40 minutes of practice/racing. Are your combined runs for the day in autocross less then 40 minutes?

I can see you needing only about 1.0 to 2.5 gallons per run. So with that small a 'cell' I'd plan in refilling during the day.

[OneWayOut]

Are your combined runs for the day in autocross less then 40 minutes?

At Nationals, we pay $175 for six runs. The slowest CM run was just over 60 seconds. So yes, less than 40 minutes.

[Lynn]

A typical autocross run is 40 to 60 seconds. Usually, three to six runs per driver. It is possible that two drivers would be in open and two women in Ladies.

[CM/FFdriver]

I am considering replacing my leaking 5 gallon fuel bladder with something smaller. Something off the shelf would be ideal, or I suppose I could have someone custom-make a smaller bladder and cover. A dipstick, sender, or sight tube for fuel level would also be a nice addition, as I currently have none of the above.

The general consensus seems to be that 1-3 gallons is plenty for a full day of autocross. A number of people seem to use drag racing or go-kart fuel cells with no separate bladder and no foam, and that would certainly cut down on the costs as well.

Any other ideas? What do you use?

I have a 3.5 gal fuel cell with foam, in 6, 71.xxx sec laps I could burn almost 3 gals of that so cutting close but I have never run out of gas. It all comes out to how much room you have to fit your car. One just like this but I wouldn't buy it from summit, just me.

http://www.ebay.com/itm/Two-2-RCI-Ra...BUdmwi&vxp=mtr

Ben

[2fast2stop]

Homemade, still have to finis fill neck, pickup and vent, very low CG.............


Attachment 63762

[OneWayOut]

...6, 71.xxx sec laps I could burn almost 3 gals

Say a course is a mile long, and you average 60mph, that's what, 2 miles a gallon? Considerably less than rickb99's FC. I'm thinking my car is closer to 10 mpg. I suppose it depends on how much you idle on grid, and if you are running fans. But that's another thread in itself...

Anyway, I did a quick mockup of a rectangle fuel cell cover tonight. 14.5"x7.25"x7.25" gives me plenty of room for at least a two gallon bladder. That's about the maximum I can get in a square.

...very low CG

You know, I didn't consider that. Maybe I should have my mockup go wider and shorter.

[DanW]

You will probably burn 2 to 3 gallons for an autocross event with two drivers in a CM.

Fuel pickup is important because the fuel is really sloshing around during an auto-x. Consider a Holley hydramat and baffle your tank with a simple eggcrate grid in the bottom and to keep the mat on the bottom.

https://www.summitracing.com/parts/h...rCUBoCxQ_w_wcB

[chrisw52]

Really? What kind of car are you running? A 2.0 Liter FC will consume about 4.5 gallons in 40 minutes of practice/racing. Are your combined runs for the day in autocross less then 40 minutes?

I can see you needing only about 1.0 to 2.5 gallons per run. So with that small a 'cell' I'd plan in refilling during the day.

the average distance traveled in an autocross for the entire event is sorta like the same distance as a warmup and one hot lap of laguna Seca... shut the engine off and your done for the day.

[ahowe]

I burn fuel at a rate of 10 runs per gallon plus about a quarter gallon or so for warm-up and puttering around the event site. I routinely put 2.5 gallons in my car at regional events where we are going to drive it extensively and pump out somewhere between a half gallon and a gallon at the end of the day.

Andy

[Don Elzinga]

I couldn't find a commercial fuel cell that would fit under the central bracing of the '84 Reynard. When the original fuel cell started to leak I used a 1 gal kart tank for a while, but that required refueling in grid. So I built a 2 gallon aluminum tank. It uses the original filler neck, has a rear sump with baffle (so no need to use a fancy floating pickup), and fits behind the plane of the seat back, so it was easy to make a simple flat firewall when they changed the mod car rules a few years back.

Don

[OneWayOut]

I ended up going with RCI's one gallon cell. It has a built in check value on the vent line fitting, and the fuel cap is directly on the cell (so no filler neck to require a check valve). No leaks, and both the foam and fuel pickup look good.

https://www.summitracing.com/parts/rci-2010a/overview/

It's tight, but it fits under the stock Van Diemen fiberglass seat shell. The fuel line runs through the original firewall hole, and the vent line goes through the filler hole.

[Rick Kirchner]

Solo doesn't require a bladder?

My first thought was you can make the bladder smaller but not cheaper, so all you do is reduce the re-sale value of the car if it had to have the cell replaced to run road courses again.

[OneWayOut]

Solo doesn't require a bladder?

It does not.

Club Racing GCR specific items and/or equipment not required in Modified Category are as follows:
a. Fuel cells.

For road racing, I'm going to have a replica of the original made (but with the proper dimensions and built to the current SCCA rule book). But that's next year's budget...

[bassracer]

I'm going to recommend going larger than 1 gallon. I think 3 is about perfect to handle all scenarios.

You will have to fill up for the morning warm up, and then fill up again.
Cold days have more idling
Long courses
Easiest way to "make weight" depending on site scale variation.

If you're committed to the 1 gal I hope it works out for you. If not, Fuel Safe's service for my custom cell (gave them a drawing) exceeded my expectations.

[B17overhead]

Interesting thread. I'm working on someone else's car and their 5 gal fuel cell bladder leaks like a sieve. Mfg.(Red Devil) says his own cost for a new one to fit that chassis is $1500 now.

I like Ben's alum can choice best. Nice and tall to minimize starvation under high peak g's. The height does make it a challenge to still locate behind the driver, however. This is one of those ultra laydown cars. Will probably consider putting the tank outboard of main cockpit. Makes it safer from standpoint of spillage into driver's compartment during fills. The clear tubing sight gauge is a great idea to add to it. I've grown to hate using a dipstick since it is so time consuming compared to a quick glance.

Ben, what is the situation on the 2 outlets? Would one T them together? What's inside that Two RCI tank for pickups?

OneWayOut, What is the mfg. of the tall circular one in your original posting?

Thanks!