We run a 1994 Honda Accord in Champcar. The factory tank is a 17 gallon tank, that is an odd shape, with the pump in the rear drivers side of the tank with a Walbro 255. We can typically get 12 gallons out of a stint before the car starts to "burp"/"hiccup" whatever you may call it. We've installed baffles, we've tried hydramats (get wadded no matter how strong the magnets are), we've tried and still use Walbro in tank MP-12/13 in-tank multi-point pickups. The MP-1x help "scavenge" the fuel that sloshes around at the end of a stint, but we are still only getting about 12 gallons before we hit that wall.
Obviously a fuel cell is an option; however, that does have its own issues and complexities.
We are focused on keeping the stock tank in for a few reasons.
Looking for ideas to help utilize those 5 gallons that could help us extend to the two hour stint limit.
What about an external surge tank?
After trying all that, an external surge tank would be your next best bet if the rules allow it.
Have you tried stuffing the tank full of fuel cell foam??
Tom1200 said:
Have you tried stuffing the tank full of fuel cell foam??
Forgot to mention that we will be testing that this Saturday at Sebring so more to follow. If memory serves me correctly, we can run a surge tank with less than half gallon capacity without being docked points. Guess that'll be next in our "R&D" thanks for the suggestions!
Swirl pot. Look at what Nascar is doing.
We had this problem with the Lemons Civic. I built a surge tank out of a really large remote mounted marine fuel filter that I mounted to the fire wall. When lemons asked about the filter we explained about the "crap" in the tank and the need for a large fuel filter.
The tank pump filled the filter and returned to the tank. I modified the filter mount to have a fuel pickup in the bottom of the filter canister and ran a Ford external fuel pump mounted under the intake. It was all sprayed flat black and sprinkled with dirt while the paint was wet so the extra pump was never seen.
It worked very well for years.
bentwrench said:
Swirl pot. Look at what Nascar is doing.
Isn't that just another name for a surge tank?
z31maniac said:
bentwrench said:
Swirl pot. Look at what Nascar is doing.
Isn't that just another name for a surge tank?
Yes but I'm assuming the intended implication is to do an in-tank swirl pot so as to not raise any undue attention from prying eyes. It's also a little safer than an external surge tank.
Surge tank is Chump legal. I can't imagine anybody would be upset with that for endurance racing, as longbas it's plumbed and mounted in a workman like fashion.
Toyman! said:
We had this problem with the Lemons Civic. I built a surge tank out of a really large remote mounted marine fuel filter that I mounted to the fire wall. When lemons asked about the filter we explained about the "crap" in the tank and the need for a large fuel filter.
The tank pump filled the filter and returned to the tank. I modified the filter mount to have a fuel pickup in the bottom of the filter canister and ran a Ford external fuel pump mounted under the intake. It was all sprayed flat black and sprinkled with dirt while the paint was wet so the extra pump was never seen.
It worked very well for years.
Brilliant!
I use a surge tank laid out similar to yours in my EFI swapped RX-7, it works great. The fuel return from the engine also fed it. I calculated that the tank pump could run dry for about 45 seconds before the surge tank ran dry, at WOT. Who uses WOT for 45 seconds? But many rules sets would consider it to be a second fuel tank and thus illegal.
On that note, late 80s Volkswagens had external fuel pumps mounted in a fairly large canister, IIRC about two liters in volume. Find one on eBay and use that as an external fuel pump, fed by the existing internal pump.
Excellent ideas. Gonna have to map out some of these to see what's most cost effective and feasible. I'm hoping at a minimum the fuel foam blocks help out a smidge this weekend.
Toyman! That's a wildly brilliant solution. Notes taken.
I saw people suggest the whiffle balls inside the tank to help with fuel slosh. Make sure they are the "American Made" whiffle balls so the fuel doesnt melt them. Supposedly its an old circle track trick.
http://www.turbo-mopar.com/forums/showthread.php?81141-Fuel-tank-baffling
kevinatfms said:
I saw people suggest the whiffle balls inside the tank to help with fuel slosh. Make sure they are the "American Made" whiffle balls so the fuel doesnt melt them. Supposedly its an old circle track trick.
http://www.turbo-mopar.com/forums/showthread.php?81141-Fuel-tank-baffling
I saw an OG caravan doing a massive burnout as someones signature block and got distracted on that forum.
Following to see how the fuel cell foam in stock tank works for you. We've found that once we're down to 1/4 tank, we start sputtering in hard corners.
P5Racer said:
Following to see how the fuel cell foam in stock tank works for you. We've found that once we're down to 1/4 tank, we start sputtering in hard corners.
I'm honestly not going to hold my breath and I've built our race plan out of our past experiences. I suppose if it nets us anything over 5 minutes a stint, it would be a success for a 14 our race. We typically have 6-7 stops, if we could cut one out that's a couple laps extra on track.
In reply to DirtyBird222 :
I figure anything helps short term. We're currently doing 45 minute races, but we're planning on some 8 hour ones next year, so I'm looking at all possible solutions.
Fuel cell foam isn't gonna do anything.
You can build and install a surge tank in about 1 hour.
Just do this, but without the needle valve and stuff. Just tee in your fuel return line to the surge AND back to the tank.
http://madscientistmatt.blogspot.com/2005/12/surge-overkill.html?m=1
Well, that was a quick exit. Y'all have another motor?
Was it just an oil line? Y'all were back on track in well under two hours.
racerfink said:
Was it just an oil line? Y'all were back on track in well under two hours.
Sorry I wasn't following this during race day.
1) Fuel cell foam did nothing....I take that back. It made it so the fuel gauge didn't work and 90 minutes/12 gallons was still our hard indication that it was time to pit.
2) The engine we just had rebuilt and thrown into the car a few weeks ago had coolant entering the combustion chamber during the test day. I drove back to Orlando, grabbed two spare motors, hauled ass back. We tried throwing a new head on the bottom end that was refreshed and same thing. At 11PM we started to do a whole swap. At 430, everything was back together. At 5:50, I finally had the tune sorted for the engine that went in (for some reason the baseline we use for F20Bs was flooding the combustion chamber with fuel). The spectacular smoke show we put on was an oil line that separated itself from the cooler slightly. Worried that it would happen again we just bypassed the cooler, cleaned up the engine bay since the header wrap had caught fire during that calamity, and sent it. That thing ran all day without a hitch after that. We ended up going from dead last on track to 16th overall, 3rd in class, with a semi-realistic shot at a class win.
3) Already ordered a surge tank as the next step in sorting this issue out. We're taking a few months off from racing to do family vacations, the start of football season/kids sports, and see if we can get one of our refreshed engines to actually work. The one that finished this race has well over 200 racing hours on it.
A weird suggestion or two.
The factory tank is a 17 gallon tank, that is an odd shape, with the pump in the rear drivers side of the tank with a Walbro 255
Put a small spacer (1/2 inch?) between the drivers side of the tank and the rear floor to make that side of the tank lower than the passengers side.
Vent the highest point of the tank back to the top of the filler neck to get air out of the tank.
YMMV, might not work at all. Don't blame me. Enjoy racing.
Noddaz said:
A weird suggestion or two.
The factory tank is a 17 gallon tank, that is an odd shape, with the pump in the rear drivers side of the tank with a Walbro 255
Put a small spacer (1/2 inch?) between the drivers side of the tank and the rear floor to make that side of the tank lower than the passengers side.
Vent the highest point of the tank back to the top of the filler neck to get air out of the tank.
YMMV, might not work at all. Don't blame me. Enjoy racing.
Great idea! I'll have to ask my pops if he's done that already since most of this has been his project.
We still had a blast this weekend all things considered.
DirtyBird222 said:
3) Already ordered a surge tank as the next step in sorting this issue out. We're taking a few months off from racing to do family vacations, the start of football season/kids sports, and see if we can get one of our refreshed engines to actually work. The one that finished this race has well over 200 racing hours on it.
What surge tank did you end up ordering? Since the foam doesn't work, I need to shop for one as well.
P5Racer said:
DirtyBird222 said:
3) Already ordered a surge tank as the next step in sorting this issue out. We're taking a few months off from racing to do family vacations, the start of football season/kids sports, and see if we can get one of our refreshed engines to actually work. The one that finished this race has well over 200 racing hours on it.
What surge tank did you end up ordering? Since the foam doesn't work, I need to shop for one as well.
This one was recommended to us from a friend. Couldn't find many half gallon ones out their either. FiTech Fuel Injection 50004 FiTech Force Fuel Systems | Summit Racing
I considered this one too FST, Fuel Surge Tank, Single Pump (radiumauto.com)
