Trunk mounted fuel cell install?

synolimit · 08-21-2014, 02:31 PM

Ok not to put down phunks in tank fuel starve fix, but I think I can save a few dollars by installing a trunk mounted fuel cell. I see a few benefits... 1. Save some coin. 2. Have a real fuel cell in case of a crash. 3. Move a heavy amount of weight to the very very back end even though it will get higher up for the center of gravity. My car has a 57/43 weight ratio so to move that behind the rear tires vs in front might help a few things. 4. Possibly doing an exhaust that vents out the rear quarter panels

How would I go about tackling this? Just confused about what to do with the OEM pump configuration and the floater in the drivers side tank. I doubt there's a fuel cell with two openings that will just take both units as a drop in.

Any ideas?

clintfocus · 08-21-2014, 03:25 PM

yes moving weight back will help even out the weight balance, but at the same time it polorizes the weight, so dynamically the car will handle worse in some aspects. think 911 porsche with weight in the back. I feel since the OE tank is lower and centrally located, it's actually a better location.

Seems like alot of work, and in the end you have a fuel cell in your trunk LOL

synolimit · 08-21-2014, 03:42 PM

I could always cut the trunk out and mount down low.

wstar · 08-21-2014, 03:55 PM

Even if you mount low, you don't want to intentionally put weight at the far rear end of the car. Yes, your weight distribution number for F/R would get fixed, but keep in mind that's just an approximate metric; the real goal is a well-balanced car, and a well-balanced car keeps as much weight as possible close to the CG. Hanging weight out at the end is making the car into a pendulum; it will tend to over-react.

What clint says is the truth: the stock location is pretty ideal all things considered. It's hard to place a fuel cell's weight better than that, especially given it saddles over the driveline hump to get even lower. (And really, I can't imagine a safe and correct switch to a fuel cell that would cost less than phunk's kit at the end of the day anyways by the time you factor in all the parts involved, especially if you want to fill from outside the car).

Also, while good fuel cells are designed to minimize fire risk when impacted, it's still not a great idea to stick them out on the edge of the car where they're most likely to be impacted in the first place. If I had a fuel cell, I'd at least want it to be inside the volume of the cage.

BGTV8 · 08-21-2014, 03:56 PM

You really want the weight of the fuel inside the wheelbase for best effect on handling ....

You could look at something like a JAZ fuel cell, but you are going to carve-up and destroy the rear of the car ............. if it is to be a dedicated track car it will be OK I guess, but selling it will only ever be a track car then.

If you want a cell fabricated, it will not be cheap - the cell/bag for my race car cost me over $3K for an FIA compliant cell and that was re-purposed.

Shamu · 08-21-2014, 04:02 PM

Or you could build a saddle sytle fuel cell to fit in stock location. I agree unless you are goling full on race car I'd go with current aftermarket fix for stock tank. Fuel cell is fairly expensive endevour. ..and if youre going to trouble of fuel cell might as well do return line type system with ability to regulate pressure etc. Mine ended up ultimately costing around $6K Not sure I would have gone there intially in my street car.

wstar · 08-21-2014, 04:04 PM

^ Yeah Shamu's car has a very optimal solution, especially given they walled off the fuel cell area from the driver compartment. But that's gonna take some serious fabrication and $$.

Shamu · 08-21-2014, 04:22 PM

Quote:

Originally Posted by wstar

^ Yeah Shamu's car has a very optimal solution, especially given they walled off the fuel cell area from the driver compartment. But that's gonna take some serious fabrication and $$.

yep not cheap.

synolimit · 08-21-2014, 04:53 PM

Quote:

Originally Posted by wstar

Even if you mount low, you don't want to intentionally put weight at the far rear end of the car. Yes, your weight distribution number for F/R would get fixed, but keep in mind that's just an approximate metric; the real goal is a well-balanced car, and a well-balanced car keeps as much weight as possible close to the CG. Hanging weight out at the end is making the car into a pendulum; it will tend to over-react.

What clint says is the truth: the stock location is pretty ideal all things considered. It's hard to place a fuel cell's weight better than that, especially given it saddles over the driveline hump to get even lower. (And really, I can't imagine a safe and correct switch to a fuel cell that would cost less than phunk's kit at the end of the day anyways by the time you factor in all the parts involved, especially if you want to fill from outside the car).

Also, while good fuel cells are designed to minimize fire risk when impacted, it's still not a great idea to stick them out on the edge of the car where they're most likely to be impacted in the first place. If I had a fuel cell, I'd at least want it to be inside the volume of the cage.

Is that not what our big heavy V6 is doing at front though? Depending on the cells width I can be mounted as far forward as possible with it leaning up against that rear reenforcement section. That's pretty much the rear axles. I would have a rear roll cage around it. I have to ask Doran racing I think because they fill up with the hatch open right at the back. I'd take that car in a second. At this point I'm more concerned about wiring although I take everyone thoughts into consideration.

Minute :19.
https://m.youtube.com/watch?v=Ra4C7AI1qIU

synolimit · 08-21-2014, 04:58 PM

I guess I don't see that cost. Buy a cell, buy hoses, hook up. My labors free so...I just need to see the layout I guess and what options I have for pickup and/or return.

Shamu · 08-21-2014, 06:12 PM

Quote:

Originally Posted by synolimit

I guess I don't see that cost. Buy a cell, buy hoses, hook up. My labors free so...I just need to see the layout I guess and what options I have for pickup and/or return.

Im not quoting any labor to put mine in - thats just all parts. To do a proper fuel cell with scavenging pumps, main pump, you want fuel gauge?, proper lines, safety features, fire wall, fuel intake system etc your looking at some coin. If youre not going to do it right why switch your stock tank? You'd be better off with the phunk fix. I also for short period of time cut my stock tank in half - that was cheap option as well. Doing a ghetto" fuel cell isnt going to serve you well in this car.

martin82 · 08-21-2014, 08:40 PM

someone already said it but you will basically need to build a box around the fuel cell so in case of fire it doesnt come in the cabin as fast... not worth it. Run the RRP from Phunk done!

Rangerz · 08-21-2014, 09:13 PM

Quote:

Originally Posted by martin82

someone already said it but you will basically need to build a box around the fuel cell so in case of fire it doesnt come in the cabin as fast... not worth it. Run the RRP from Phunk done!

works as advertised

wstar · 08-21-2014, 09:51 PM

Quote:

Originally Posted by synolimit

Is that not what our big heavy V6 is doing at front though?

Yes. If you can come up with a cheap mod for fitting the engine at the CG of this car, go for it

There are tons of considerations in designing a whole racecar, and I'm sure Doran's car is badass, but that still doesn't mean it's a good idea for you to stick a fuel cell all the way at the back of your car.

Rusty · 08-21-2014, 09:56 PM

Another thing too. With the fuel cell at the rear. As the fuel level goes down. It will change the balance of the car.

08-21-2014, 02:31 PM	#1 (permalink)
synolimit A True Z Fanatic Join Date: May 2013 Location: Columbus, OH Posts: 5,051 Drives: 2013 Silver 370z Rep Power: 3389	Trunk mounted fuel cell install? Ok not to put down phunks in tank fuel starve fix, but I think I can save a few dollars by installing a trunk mounted fuel cell. I see a few benefits... 1. Save some coin. 2. Have a real fuel cell in case of a crash. 3. Move a heavy amount of weight to the very very back end even though it will get higher up for the center of gravity. My car has a 57/43 weight ratio so to move that behind the rear tires vs in front might help a few things. 4. Possibly doing an exhaust that vents out the rear quarter panels How would I go about tackling this? Just confused about what to do with the OEM pump configuration and the floater in the drivers side tank. I doubt there's a fuel cell with two openings that will just take both units as a drop in. Any ideas? __________________ 13 370z-

08-21-2014, 03:25 PM	#2 (permalink)
clintfocus Track Member Join Date: Jan 2011 Location: los angeles Age: 39 Posts: 933 Drives: 370z, EK Civic, F150 Rep Power: 15	yes moving weight back will help even out the weight balance, but at the same time it polorizes the weight, so dynamically the car will handle worse in some aspects. think 911 porsche with weight in the back. I feel since the OE tank is lower and centrally located, it's actually a better location. Seems like alot of work, and in the end you have a fuel cell in your trunk LOL FL 4Motion, phunk and sig11 like this.

08-21-2014, 03:42 PM	#3 (permalink)
synolimit A True Z Fanatic Join Date: May 2013 Location: Columbus, OH Posts: 5,051 Drives: 2013 Silver 370z Rep Power: 3389	I could always cut the trunk out and mount down low. __________________ 13 370z-

08-21-2014, 03:55 PM	#4 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3594	Even if you mount low, you don't want to intentionally put weight at the far rear end of the car. Yes, your weight distribution number for F/R would get fixed, but keep in mind that's just an approximate metric; the real goal is a well-balanced car, and a well-balanced car keeps as much weight as possible close to the CG. Hanging weight out at the end is making the car into a pendulum; it will tend to over-react. What clint says is the truth: the stock location is pretty ideal all things considered. It's hard to place a fuel cell's weight better than that, especially given it saddles over the driveline hump to get even lower. (And really, I can't imagine a safe and correct switch to a fuel cell that would cost less than phunk's kit at the end of the day anyways by the time you factor in all the parts involved, especially if you want to fill from outside the car). Also, while good fuel cells are designed to minimize fire risk when impacted, it's still not a great idea to stick them out on the edge of the car where they're most likely to be impacted in the first place. If I had a fuel cell, I'd at least want it to be inside the volume of the cage. FL 4Motion, phunk, sig11 and 1 others like this. __________________ 7AT Track Car! Journal thread / Car setup details Last edited by wstar; 08-21-2014 at 03:58 PM.

08-21-2014, 03:56 PM	#5 (permalink)
BGTV8 A True Z Fanatic Join Date: Dec 2009 Location: 03350 Australia Posts: 1,514 Drives: 09 Nissan 370Z M6 Rep Power: 39973	You really want the weight of the fuel inside the wheelbase for best effect on handling .... You could look at something like a JAZ fuel cell, but you are going to carve-up and destroy the rear of the car ............. if it is to be a dedicated track car it will be OK I guess, but selling it will only ever be a track car then. If you want a cell fabricated, it will not be cheap - the cell/bag for my race car cost me over $3K for an FIA compliant cell and that was re-purposed. Rusty likes this.

08-21-2014, 04:02 PM	#6 (permalink)
Shamu A True Z Fanatic Join Date: Jan 2011 Location: Nor Cal Posts: 1,059 Drives: 370Z Racecar Rep Power: 19	Or you could build a saddle sytle fuel cell to fit in stock location. I agree unless you are goling full on race car I'd go with current aftermarket fix for stock tank. Fuel cell is fairly expensive endevour. ..and if youre going to trouble of fuel cell might as well do return line type system with ability to regulate pressure etc. Mine ended up ultimately costing around $6K Not sure I would have gone there intially in my street car. phunk, sig11, BGTV8 and 1 others like this. __________________ Grant Last edited by Shamu; 08-21-2014 at 04:06 PM.

08-21-2014, 04:04 PM	#7 (permalink)
wstar A True Z Fanatic Join Date: Mar 2009 Location: Houston, TX Posts: 4,024 Drives: too slow Rep Power: 3594	^ Yeah Shamu's car has a very optimal solution, especially given they walled off the fuel cell area from the driver compartment. But that's gonna take some serious fabrication and $$. __________________ 7AT Track Car! Journal thread / Car setup details

08-21-2014, 04:58 PM	#10 (permalink)
synolimit A True Z Fanatic Join Date: May 2013 Location: Columbus, OH Posts: 5,051 Drives: 2013 Silver 370z Rep Power: 3389	I guess I don't see that cost. Buy a cell, buy hoses, hook up. My labors free so...I just need to see the layout I guess and what options I have for pickup and/or return. __________________ 13 370z-

08-21-2014, 08:40 PM	#12 (permalink)
martin82 A True Z Fanatic Join Date: Nov 2011 Location: los angeles Posts: 2,636 Drives: 12 Nissan 370Z MB M6 Rep Power: 20	someone already said it but you will basically need to build a box around the fuel cell so in case of fire it doesnt come in the cabin as fast... not worth it. Run the RRP from Phunk done! Rusty and Rangerz like this.

08-21-2014, 09:56 PM	#15 (permalink)
Rusty Ronin Samurai - Assassin Join Date: Dec 2011 Location: Fayettenam,Pennsyltucky Age: 68 Posts: 35,217 Drives: 2011 Nismo GM 6M Rep Power: 2684438	Another thing too. With the fuel cell at the rear. As the fuel level goes down. It will change the balance of the car. phunk likes this. __________________ 浪人 - 殺し屋 "The Difficult Anytime, The Impossible By Appointment Only" http://www.the370z.com/members-370z-...o-journal.html

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