kjewer1

iTrader: (4)

It takes up to 3-4 minutes to drain the tank, depending on what pump you have, how much fuel you are draining (should be less than 5 gallons so it fits in one jug), and whether or not you run the car while you run the pump (voltage affects flow rate).

Swapping out the fuel is more cost effective (I only buy one gallon per trip to the track), better for high boost since you know it's not diluted (aside from the ~1 gallon the pump can't pick up), and easier on your O2 sensors since you're not running it in the tank for long after you're done racing (depends on how low you run the tank before refilling). It's the only way to go IMO, especially if you race regularly.

I have considered for a long time running a seperate fuel cell that can be valved in for hte race fuel, since I run at the track one to two times per week, and swapping fuel gets real old. I also hate having to carry the race fuel and a second jug in the trunk all the time, the car reaks of gasoline. The problem is that it is a bit expensive, it puts you out of certain classes (like Nopi PS for example), makes tech at a strict track that much more painful, and you have that added weight to carry around even on the street. After 3 years I still haven't decided if it's worth it or not.

thekuai

iTrader: (8)

i think a fuel cell system saves you about 30 lbs over stock....and i was thinking of doing a 5gal race 5 gal pump tank....so i don't think the weight will be penalizing me...the thing is I dont just race at the track if you catch my drift and it will be kinda awkward when a certain "match" is agreed upon...."ok guy lets do it.....o wait a few minutes i gotta drain my tank and fill it with RACE GAS....."

and after reading trinababe's fuel cell thread It would only cost me about $1000 for all the parts

fre

iTrader: (4)

I don't race that often and swapping fuel only takes 5 minutes max as said before. It's not worth the *** pain of installing a race fuel cell in my opinion. My friend runs a 9 second talon and he still uses the stock fuel tank. Of course he rarely puts pump gas in it anyway.

On the other hand, if you have the money to burn then go for it.

94AWDcoupe

iTrader: (125)

You should try the fuel return line method . Then remove the fuel plugs and see how much more comes out. I bet its over two gallons left in the tank.

fre

iTrader: (4)

The thing that wouldn't make sense to me is if you have a 14 gallon tank then only 12 gallons is useable? Meaning the fuel pump can't pick up the bottom 2 gallons? That just doesn't make any sense. You would think the engineers would design it a little better than that. I could be wrong and if I am oh well.

kjewer1

iTrader: (4)

I pumped out the tank at a gas station once, then filled it up. I can't recall the exact numbers, but I came up with something less than 1 gallon that the pump can't reach.

fre

iTrader: (4)

This makes more sense.

Nad1370

iTrader: (1)

Actually, the engineers did thought about that very well.
Evo has an AWD drivetrain. In order for it to have a bigger gas tank, they had to use a " saddle bag " type of tank. One on each side of the driveshaft. If not, we'll only have a 7 gallon tank .
If the fuel pump side tank gets lower, it siphons off the other tank. Fuel pump is surrounded by a bowl type basin. This basin prevent the fuel from getting plastered to the wall during hard cornering. This basin also acts like a dam so even if you stall out of gas, the left over fuel on the other side of the tank + fuel outside the basin = 1-1.5 gallons.

fre

iTrader: (4)

Well the person that posted the test results is probably accurate since he actually did a test based on 14 gallons and is not just speculating. So I will go with his results

tony gibson

iTrader: (1)

I too use the method Fre talks about (I got the idea from him, my fellow military Tarmacblack owner ) and it works great for me as well...A piece of vaccum hose about 4-6 feet that fits over the fuel return hard pipe right by the fuel rail should do the tric...better than crawling under the car IMO

94AWDcoupe

iTrader: (125)

Its more like a 16.5 gallon tank with 14 usable. Fuel pickups are not very close to bottom of tank. I have used the fuel pump method on various cars when I had to remove tank for service. Always amazed/pissed at how much fuel is left in tank.

This is why I always warn people about running race gas in their car when they never drain the tank properly. You never have a consistant mix. Especially when you ad some race gas a couple of times a week. You never know how much race gas is left in that last 2 gallons thats left in the tank. Octane unkown is a dangerous thing.

wspy

You guys are forgetting how the fuel system works. There was mention of the saddle type tank, now, how the fuel gets from the left to the right side is by a siphoning method. The fuel returning from the engine is routed to the right side of the tank through a siphoning apparatus. The action of the fuel moving through this piece draws fuel from the left side of the tank. So, if you disconnect the return line at the regulator,as suggested previously, you are in essence turning off the the siphoning action from the left side of the tank so that any fuel that was left in it will stay there and you will only be draining the right side of the tank, the side that the pump is in! Thus the illusive 1-3 gallons that we all are talking about.
You can drain the tank ( RHS ) pretty well with the "car idling and return line" method, but if you use this method you must remember that whatever fuel was left in the LHS will now be mixed with your race gas once you reconnect the return line.
Hope this helps

fre

iTrader: (4)

After reviewing the manual I understand the concept, but I would have to confirm that the tank is 16.5 gallons and only 14 is useable. Again, that doesn't make any sense.

kjewer1

iTrader: (4)

Am I the only one thinking that my pump feed/return is on the LEFT side of the tank? Either way, the return is on that side, but the fuel passing through it back into the tank siphons fuel from the passenger side tank into the drivers side.

At any rate, if you are getting to the track and expecting to drain your tank into a 5 gallon jug (I usually get 2-3 gallons), none of the above discussion applies. There is no fuel in the other side to pull over...