1st Gen Camaro Fuel Cell mounted in trunk below package tray?

[GeoffP]

First I wasn't sure where to post this so I thought this section made the most sense for what I want answers on, thinking this is safety related as well as improved weight distribution (or at least I think it would be).

I'm curious why no one has ever made a fuel cell that mounted up on the "hump" of the truck directly behind the back seat. The only negatives I can think of are as follows but I think they could be solved with some creativity.

1. IMHO, the truck area would need to be sealed off from the passenger compartment since a collision would create a fuel/fumes safety issue if the cell is ruptured (thinking a cell with a safety bladder would help with this too but don't most have a bladder already?)
2. I think the high point of the hump might outweigh moving the fuel forward in the body - opinions on this?

On the positive side, it would allow for a quarter mounted fuel fill door or a hidden filler inside the trunk moving the filler away from the tail of the car.

If this makes sense, please post your opinions on why you think buying a cell that would fit in that location or having a custom cell built for it would be good or bad.

Thanks!

[astroracer]

I don't know what the rule books say if this is in a race/track style car. You would definetly have to use a steel can to seal the cell. The biggest reason I can see to NOT do it (in a race car) is CG. A full tank will change the CG of the car to the point that it may cause a dramatic handling change once the fuel starts to get low. Possibly to the point that it becomes ill mannered.
This is just conjecture on my part but I know the goal in a race oriented build is to keep the CG as low as possible and this cell placement goes against the grain. It wouldn't be that much of an issue on a street only car but I will wager you will be able to feel the difference between a full and empty tank, even on the street...
Mark

[Randy67]

The 04-06 GTOs had the tank in that position due to US safety crash regs, Aussie tanks were under the truck floor. But other than that, I haven't seen any cars (street or race) that have the tank that high so there probably is a concern with effects on handling/CG like Mark said. One thing, you will need a firewall behind the seat, most rules don't look at the steel container (with the bladder inside) as a firewall. Better safe than sorry.

On a side note, I have thought of trying to adapt the late-model tanks that are under the rear seat (Camaro, Mustang, 89-97 Tbird), just not sure how to run the exhaust.

[Randy67]

Sorry, double post. Computer/network issues.

[Twentyover]

The 04-06 GTOs had the tank in that position due to US safety crash regs, Aussie tanks were under the truck floor. But other than that, I haven't seen any cars (street or race) that have the tank that high so there probably is a concern with effects on handling/CG like Mark said. One thing, you will need a firewall behind the seat, most rules don't look at the steel container (with the bladder inside) as a firewall. Better safe than sorry.

On a side note, I have thought of trying to adapt the late-model tanks that are under the rear seat (Camaro, Mustang, 89-97 Tbird), just not sure how to run the exhaust.

If I remember correctly,the first generation Celica had the tank in this location. I think I remember one wall of the tank being the partition between the trunk and passenger compartment. On my brother-in-law's SCCA proddy race car, we used an ATL 'Well Cell', a round fuel cell that sat in the spare tire well.

In the grand scheme of things, the best condition would be a regularly shaped tank placed with the center of' 'mass' of the tank would be along the roll axis.

[GeoffP]

Thanks for all the input. I've had this idea rolling around in my head for awhile and wasn't even sure if it would be viable to try. I'm not racing other than American Street Car series events so there aren't any "firewall" rules. However if I were to even consider this I wouldn't do it without making sure it's safe. I've also considered the 3rd/4th gen style tank location but it prevents using pretty much any aftermarket suspension systems.

[GeoffP]

I find it VERY interesting that Detroit Speed is building a car right now using this very same idea for the fuel cell. I hope they will share how it works out!! There must be a little something to it after all...

http://www.detroitspeed.com/projects/mcgilton/mcgilton-cvyII-pg1.html

[XLexusTech]

its been done... i looked for the car earlier this week... it uses a pickuptruck fueltank behind the rear seat and in fromt of the axle.

[Hoosier]

I installed an 06 GTO fuel tank under the package tray and put the filler in the sail panel.

[GeoffP]

Hoosier - have you got any pics of the installation? I'd be curious how that worked out for you!

[GeoffP]

Looking at the GTO tank it appears to be a nice fit if it's not too tall to fit on the upper deck of the trunk. The biggest issue I see is figuring a way to get fuel into it without hacking the body up.

[rchaskin]

I find it VERY interesting that Detroit Speed is building a car right now using this very same idea for the fuel cell. I hope they will share how it works out!! There must be a little something to it after all...

http://www.detroitspeed.com/projects/mcgilton/mcgilton-cvyII-pg1.html

That is so funny.......
I looked at that same set of pictures and thought, man what a speaker box.......

[Dantigan]

I have decided to use the GTO tank out of my donor car in my '69 Firebird build. Doing some measurements it is about 2 inches taller than the package tray. My plan is to level out the area on the bottom and cut out the package tray. I will then weld in a support cage to hold the tank similiar to factory and reinstall the package tray just above the tank. I will put a full firewall on the front, probably using the GTO's wall. I will put an aircraft type filler on the sail panel. I will probably install the crash bar that goes behind the tank from the GTO as well for safety.

I know a lot of people will criticize the use of a tank mounted behind the rear seat. The way I see it the only downsize is the change in center of gravity. But the benefits are the added room for exhaust which needs to go over my watts link, leaving room for the exhaust to go through the tail panel through some custom cutouts. It will also help clean up the custom tail panel that is being built.

As I have driven the GTO on a track with the tank in that location it seems to be planted on the ground just fine. I don’t foresee a huge difference in my 'bird.

[GeoffP]

I hope you get some pictures though I am disappointed that the GTO tank doesn't fit under the package tray without modifications.