Fuel Cells

[Pop N Wood]

Alright, collecting opinions on exhaust and fuel cell layout.

 

For a V8 swap in an early 240 it looks like a dual exhaust with 2 full sized turbo mufflers will give me a quiet ride with good performance. Target HP range: probably 300 HP but don’t want to rule out an eventual build up to 400+ HP. To accomplish this I have just about decided I can live without a spare. The question now becomes what is the best way to accomplish this?

 

My problem is I do NOT want the fuel filler inside the car. I have enough trouble with spilled coffee.

 

From spending half my working hours perusing this site ( ) I have come up with several options that appeal to me:

 

1 Keep stock fuel tank, hammer down or remove the spare tire well and put both mufflers on the left rear corner.

 

2 Lose the spare tire well and stock tank, put a fuel cell in the middle and mufflers on the left and right corners.

 

3 Put both pipes straight down the middle with a small tank in the right rear corner. (Someone on this site has this combo.)

 

4 Sidepipes.

 

The car will be a summers only street machine that will hopefully see some club racing.

 

I really like the look of dual pipes anchoring each corner of the rear end! This would allow some flexibility adjusting the exit location to avoid possible exhaust fumes in the car. (Saw this topic in a very old HybridZ post.) Problem with this (I assume) is I cannot reuse the stock fill location since it would have to cross over a muffler. This leads to a custom made tank and/or fuel cell mounted in the center. But then what are the options for a fuel inlet? Has anyone tried building a flip down license plate with a fuel filler behind it? Could I find a fuel cell that would support this or do most fuel cells have the fill location TDC?

 

What would be involved in making a tank from scratch? Does anyone have any convenient links illustrating how to build a tank (with tips on baffles, internal coatings, flexible fill tubes, etc.)? Should I be worried about the Pinto syndrome? Or is it best to modify a junk yard tank from some other vehicle?

 

Finally, has anyone discovered or made an oversized muffler with dual 2 ½ inch inlets and a single outlet? Something like this might fit in the stock muffler location and allow me to keep the spare tire well in tact.

 

Opinions?

 

Alternate suggestions?

[Guest Anonymous]

The first tank I had on the car was from a junk yard pile of tanks. I Have dual exhaust like you describe. I found a tank that had the measurements I needed and the filler neck on the correct side. Bought a length of filler hose at the local napa store and made the connections with large radiator clamps. It worked great as far as filling from the stock location but it needed baffels or an internal pump. Had fuel starvation below about a half a tank in any kind of tight turn. If you could find a tank the right size, with the filler neck in the right position with an internal pump....

Good luck. Mark

[Guest Big Phil]

Jim,

I had placed my fuel filler behind my license plate on my 78 280z. I used the orginal gas tank and moved the inlet from the side to the top. It looked pretty trick but I had to change the filler location when I changed the taillights.

 

I just purchased a 15 gallon fuel cell from Summit and I am also planning on running dual exhausts. There is a gentleman in California that runs dual exhausts and his fuel cell is filled from the stock location. I'm going to copy his installation because it is clean and allows more than enough clearance for the exhaust.

 

fuel cell install

 

Phil

 

P.S. If anyone in Southern California wants my modified tank, just come and get it.

[BLKMGK]

FWIW, my filler is inside, yeah I don't like it either but for occasional fun car use it's not so bad. It's under a sheetmetal "house" so technically it's not IN the passenger compartment. Also, if I had to do it again I'd go with a BIGGER fuel cell and shift it to one side. A BIG single pipe oout the stock location looks nice IMO and involved no cutting of metal to accomplish. I run a total of three mufflers now and it's quiet enough at last with some resonance still there.

[VRJoe]

I'm having my fuel tank ('77 280Z) modified by the local radiator shop. They're removing the area from below the fill and return lines and almost over to where the mounting stap fits. I figure I'll loose about a gallon of fuel, but it'll allow the pipe to slide right on by This way everything hooks up as before. I have some pictures of the cut out, once it's all done I'll post pictures of the whole thing. I just stopped off today and we decided where the return line should be moved to.

 

-VRJoe

[Guest Anonymous]

Ive got a bit of a problem, ive got an aftermarket fuel cell, and an autometer gauge that doesnt seem to pick up correctly. What should i look for??

thanks,

franklin

Its hot down here!

[Guest 72240Z]

I'm using a 1986 Mazda rx7 fuel tank. It has baffles and an in tank pump for my LT1, the sending unit has allmost the same ohm range as the datsun sender, and the filler neck is on the right side. It's mounts in the center and will let me fit dual exhaust. It's not finished yet but will be soon.

[Guest kc6wfs]

72240Z,

 

How many gallons is that tank??

 

Thanks.

Dave

 

[jhaag]

Fuel Safe Racing Cells (http://www.fuelsafe.com/aboutfuel1.htm) apparently can custom make a fully functional fuel cell with external dimensions of stock gas taknk so it fits in the factory location. So says an article in the June, 2002 issue of Car Craft (page 84). The article doesn't state if it uses the stock fill location but read the column that is titled, "Custom Fuel Cells Made to Order." Other firms may do the same thing. Of course, when the word 'custom' is used, I'm sure the price goes up.

John

[Mike kZ]

I used the stock 240Z tank but added a sump to the bottom (327 EFI). I then centered the tank, after removing the spare tire well, and made new straps to hang the tank. I used a short piece of exhaust pipe to extend the fuel pipe to the tank in the new location so I could use the stock filler. Now I have dual exhaust on either side of the tank. There is room to put a muffler on the fuel pipe side but it would have hung to low for my liking. So I used a custom made Spintech muffler, dual inlet and outlet just ahead of my diff then ran pipe to either side of the tank, with resonator tips on the ends.

[Guest 72240Z]

I'm not sure how many gallons it holds, but I will measure it soon and let you know.

[Pop N Wood]

Thanks for all of the input guys, some ideas to chew on.

 

Having such an early 240 I don't see how it is possible to string together 3 mufflers and still have ground clearance. Guess it can (and is) be done. The JTR manual was kinda down on the need for dual exhaust. Maybe I will go single pipe with the a near stock motor transplant, then go fuel cell/duals if and when it goes high HP. From these posts I get the idea there is a little more room for the stock fill pipe than I imagined.

 

I like the idea of the custom muffler in front of the diff. Would like to see pictures if anyone has that available.

 

Also really like VRJoe's and Big Phil's approaches. Looking forward to any pictures!

[Guest gprix1]

Here's an idea I've kinda tossed around in that empty space between my ears. I've been thinking of leaving the stock fuel tank where it is, cutting the front and back of the spare tire-well open and having the mufflers actually inside the spare tire compartment and exiting straight out the back ala Mclaren style. Of course I would have to build a cover over it for inside the car to keep heat, noise, and exhaust out but what do y'all think?

[V8ZRACER260Z]

I have a 30 gallon alluminum fuel cell with the filler behind the tag. I welded in a box to keep the fumes out and made a straight panel covered in carpet across the rear. This allowed me to run 2 1/2" out either side. I notched the rear valance to match the original location.

[Guest gprix1]

V8ZRacer,

Do you have any pic's of your fuel cell setup? Also, I see you are going with a Corvette suspension in the future. I too am going that route and currently have an '84 IRS in my garage that's going in my 240Z soon.

[Guest 72240Z]

kc6wfs here is the info you wanted about the mazda fuel tank. Acording to mazda it holds 16.6 gallons of fuel and the fuel pump puts out 65 to 85 psi fuel pressure.

[Guest kc6wfs]

Thanks!!!!!

 

Dave

[pparaska]

Originally posted by Jim Powers:

From spending half my working hours perusing this site ( ) I have come up with several options that appeal to me:

's o.k. I won't tell a soul

 

 

1) Keep stock fuel tank, hammer down or remove the spare tire well and put both mufflers on the left rear corner.

Jim, this is what I did, in a way, but I cut out about 1/3 of the spare tire well (thinking I would put a mini spare in the remaining area - gave up on that with my big brakes needing a big wheel). Check out the pictures on my site (under exhaust mods) and/or come by my house to see it in person (I'm near rt 29 and rt 216). I'll send you an email.

 

I just didn't want to bother with a fuel cell. If I ever go to EFI, I'll build/buy a surge tank and hook it to the stock tank with a pump between them.