Does any one run their fuel cell in the rear trunk? The front of the car would not be losing weight as race goes on so it would be more consistant for keeping suspension settings.

okay, i thought about it, and i think it's a really bad idea.

the spare tire area of the front trunk (the standard location for racing fuel cells) is a LOT lower than the back trunk. it is A LOT cooler. it is a lot deeper - i.e. - much less slosh. slosh is unpleasant in transient cornering and it makes it really hard to keep the pickups covered.

for endurance racing, it means you get to fuel right next to the hot engine and exhaust -- and in-race refueling always involves some splashing.

there's going to be some cg change no matter what you do; i think i'd rather have the front go light (understeer - stabilising...) than the rear ...

but other than that ...

what he said!!!

In all my years of 914 voyuerizum I have only seen one race car that didn't have it in the front.

This guy had it in the passenger seat foot well.

Paul

all I can think of is "Pinto"

I know that others have made comments in the past about 50/50 weight distribution not being ideal in a race car......

but I'm still not convinced on that one...

on top of the above comments.
the rear is heavy on a 914, and the last thing I'd want is to add another 100lbs back there.....

I just mounted a cell last month, and choose the standard front location.... The local 914 guru-race shop made me up a custom aluminum housing for a standard fuel safe bladder.... We cut through the front bulkhead into the fuel tank area... Got the cell mounted 1/2 inch clear of the sway bar and down 1/2 inch from the floor bottom.. Came out excellent. After I get the 35mm's back from development I'll try to have a few scanned.

brant

I mounted a 15 gal Fuelsafe tank in the front of my 914/6 GT, raised above the floor since I have the big front cooler, & have raced it that way since 1992 with little apparent effect on weight bias;

the ideal setup is to take 2 old stock tanks, cut & join halves at the flanges and install a bladder into that setup in the stock location, keeping the weight between the axles as Porsche intended; I have a picture of one in a vintage VARA car and a pair of tanks to build one; whilst the 15 gal tank is now living in the REAR trunk of my MGB racer

old-time Stoddard mechanic & 914 racer told me to put the battery in the right front corner to offset both driver & rear weight

Larry,

I still think the stock location is a bit high up (CG)
With the bulkhead cut open, its actually not that much forward of the stock location and WAY lower....

the top of my tank is the same height as the bottom of the stock location.

brant

my car is 'way too valuable to cut up the bulkhead & do other such surgery....
http://www.pelicanparts.com/gallery/larryM

welcome larry.....

we missed you at the WCC last year, it would have been nice to see your car again...has Fred finally retired yet??

Given unlimited time & budget...or at least more of both than I have....the longs look like a gud place to me. Aluminum tanks with bladders...both sides.

Fuel tanks in the side pontoons was the standard back in the 60's and 70's for open wheel and sports prototypes. Those cars initially had aluminum tanks without bladders. Talk about fire traps. Later designers began moving the fuel tanks to more central locations for better weight distribution. But the main reason side tanks disappeared was that rules makers required tanks to be centrally located for safety reasons, i.e. away from direct inpact. Now all F1, Indy, sports prototypes, etc. locate the fuel cells in central locations to meet the rules and to limit weight distribution changes as fuel load varies.

Well, at least that what I think happened...

I mounted my fuel cell in the passenger footwell.

For me, it's what I needed to do, and, in theory, I like the weight further back than between the front wheels. I currently have a 56% rearward weight bias.

Larry,

Nice car.
I wouldn't want to cut that one up either..
but Ideally, I still think that the most competetive 914's are cut up and modified in ways that the factory never dreamed of...

so I'm sticking to my theories that lower weight is better.

brant

I agree that the lower the better.

Also I remember there was a FV not far from where I lived when I was a kid and the seat WAS the fuel cell. The top of the cell was molded and shaped and you sat or sorta laid on it.

Paul

visions of the Porsche 909 'Bergspyder' hillclimb car, where every gram was considered crucial.
beryllium (!) brakes! no fuel pump! the driver sat on the fuel bladder and his weight pressurised the fuel long enough for a hillclimb run...

so Paul - you ready to save a pound on a fuel-pump replacement technique ? you only -need- enough fuel for a couple of minutes to get through an AX course ...

Don't forget about that screwdriver in you back pocket driving that car!

And I thought the spare tire powered windshield washer was crazy.

Andrew

I thought you would not have the slosh with a foam filled cell. As for the gas by the hot engine..... Its there with the fuel lines and carbs and on a normal car your exhaust is close to the gas tank so that is a wash. I dont plan to be in an event that I would need to refill mid race.

you seem determined to do it, so go for it. it's your car, do what you want.

the foam helps with slosh, i'm sure, but MOSTLY it's there to prevent a place for vapor to accumulate. liquid fuel will burn but it won't explode; vapor will explode.

it's not quite a wash - those cars are pretty much stuck with it, i don't know why you'd go out of your way to store fuel in a hot location, but try it if you want. a front engine car has many feet between its hot engine and its hot transmission, but they are in front of and under a 914's back trunk.

just remember 140F. plus or minus a little, that's the boiling point of gasoline.

How about these ideas:
I was thinking of pressuring the cell with air and deleting the pump.

And I was going to use the roll bar tubes to carry the fuel to the engine, ala 917.

Or delete the cell all together and only run fuel in the tubes.

Or shallow the gas and and piss while driving into a tube to the carbs...

Do I need to keep going???

Brant; I'd be real interested in seeing pics of your fuel cell. I've been kicking around an idea for an L shaped cell that would sit partially in the stock location and part on the lower trunk floor. The bulk head would have to be cut. This would lower most of the fuel weight while not moving it forward too much. I don't know who I could ask about making such a cell and it might not work for some reason but I'd like to find out.

You know I don't think the location of your cell in the passenger foot well or in the front trunk is really going to lower your lap time by .0001 of a second.

Don't over engineer the thing. Put it in and go racing.

(OK, I know what your thinking, this comment coming from the dumbass that cut is car all to hell to make it go .0001 faster)

Paul

I'm on vacation until friday...
does anyone have a scanner...
I've got some mounted fuel cell 35mm pictures that I could mail, but no digital abiilities.....

brant