Zneed4speed

Anyone installed one?
Tips?
Pics?
The Kokeln cell is too expensive.

RedlineMan

Hey RL;

The Kokeln cell is insane even though it does fit the space. You could have Fuel Safe or ATL make a custom for half that.

I will be doing it sometime in the next year or so, and fairly cheaply at that (WELL under a grand WITH a drybreak system!), but it is not a project for the faint of heart. This is a place where Porsche really outdid themsleves in terms of packaging efficiency.

To use a generic cell configuration you have to have a heavily modified car (no floor) unless you don't care about center of gravity, or having a very small cell.

Alan C.

There are a few of us who will be installing new cells this year. Chris White, Jeff Lamb and myself. May be some economy of scale in here.

Zneed4speed

>>To use a generic cell configuration you have to have a heavily modified car (no floor) unless you don't care about center of gravity, or having a very small cell.<<

Hey John,

I expect to cut the floor. I'd like a 15 gallon cell and use the original filler. Hell, I'd like to have a guage too.:-).
I would also want to build some sort of aluminum "cover" to protect things a bit.

RedlineMan

Hey;

My rear floor is gone from the end of the passenger floor pan back to the rear body panel and is sheeted in aluminum now. If anyone had reason for a firesuit at a DE, it would be me!!

I also have a tube frame surrounding the perimeter already. I have not decided on the size or stats for my cell yet. It will either be 16 or 22 gal, either 8.5 or 10" height, and have a sending unit. Check out JAZ Products. Not fancy cells with soft bladders and such, but 1/3 the price of ATL or Fuel Safe. 22gl for under $300!

It is a tricky balancing act between CG, F-to-R weight bias, and cell size. I cannot afford the expense of a custom cell in front of the trans, so I'm going conventional. It will end up slightly behind and above the current tank, but it should be reasonable. I'd love to have it under the floor height, but you just can't swing it unless you go REALLY small. I know a guy who has a flat floor, but only a 10gl cell. I am too lazy for that. I run all day on a tank at the track, and that's my benchmark!

www.redlinerennsport.com

Zneed4speed

Yeah I need bigger than a 10 gallon. Do you think there's room for two 8 gallon cells below the floor?
One on each side of tranny? I'm trying to picture the cross member the tranny hangs on wihtout the floor and the room...
I looked at your site but didn't see any pics of your cut out floor. Got any?

Bill L Seifert

I talked to some company, and they suggested the Donut style, but it was only 12 gals. Would some of you working on one please post pictures?

Bill Seifert

1983 944 Race Car

RedlineMan

Hey All;

I'm about ready to contract one of the companies to build customs for us. Seems to me we could have one made that would fit the stock location with no floor mods for under a grand. I wonder if there is enough interest?

I can see it now...

"Redline Rennsport 944 Fuel Cell. All the Safety for a Sane Price!!

I have not taken pictures of my car yet. It is just a cut out floor for now so I didn't think it would be that interesting. Maybe I'll do that this afternoon. The Rabbit Ice Racer project is leaving and I'll have my lift back!

Z - I looked closely at two cells, but it just seemed like a lot of work and expense what with all the cross tubing for fill/vent, wiring for senders, and such. I used to carry tires and stuff in the car so I wanted the floor flat, but since I don't use the car to haul stuff anymore I figure the flat floor is not that necessary anyway.

Alan C.

If you have the stock tank in front of you it is basically an 'L' shape with the short leg hanging down on the pass. side. That doesn't seem like a hard design. There are some cut corners and a ledge designed in but you could eliminate those and end up with a tank with all straight cuts. That might cost a gallon or two. However, on the cost side it might be worth it.

Keep me informed John.

Thanks

Geo

I'd definitely be interested.

The current direct fit are just way too expensive to justify and I won't hang one in the rear due to safety and balance issues.

One thing I thought about was twin cells mounted where the rear seats are and just combine the lines under the car. this would reduce the polar moment of intertia and also lower the mass of the fuel.

SeaCay

Chalk up another interested person.

Keep the list informed of your progress.

Zneed4speed

I got a look at one of the K$$keln cells late Friday night. The cell was uninstalled locked in the rear hatch of a car in progress. It was dark and we were lifting the cover over the car but the thing looked nice(welds, aluminum finish).
It sort of looked like saddlebags, which makes me wonder about getting fuel out of both compartments.
I can get a closer look next week.

RedlineMan

Gents;

Here's some initial pics of my rear compartment in my 84. They are essentially the same in all years as far as I know, with the exception of tank material. This shows my rear floor which is sheeted in .063 T6-6061 alloy. Front & rear shots.





This is the open shot.



You will note that I have a tube frame (rear only at this time) built inside the existing body shell. It employs saddle tubes running down the side frame rails and everything else built on top of that. My floor deck height is 1.75" higher as a result.

The rear square tube x-member you see - which is removeable - was added to give the tank something to be trapped against in the absence of the floor, and utilizes much of the OE hardware for the straps. The right strap has been modified to match the left for length. The front x-member is also fabricated (1.75" tube), as are the .125" steel plate upper shock mounts. The OE fuel lines were maintained until final configuration is settled upon. There has also been some vent system spaghetti removed.

The only thing you can't see is the OE front x-member. It runs side-to-side roughly in line with the filler neck. The shallow front of the tank (about 4-5" in height) sits on top of it, and in the early cars it is also where the trans hanger mounts are bolted underneath. The later cars use a separate removeable trans x-member, but I believe the fixed sheetmetal x-member remains.

The two inch tape you see is marked with the centerline of the space available, which is also the centerline of the trans. The 3/4" tape marks the width of the trans housing. The tail of the trans (Turbo pumper) is just visible under the rear of the tank. The hoses go to the remote mounted cooler.

I will at some point be pulling the tank and making various mock ups of tank shapes from cardboard to explore the space and positioning options. Suffice to say that the OE setup is a marvel of space utilization and efficiency. Unfortunately, this makes it VERY difficult to come up with a really efficient solution in terms of polar moment.

I am currently ruminating on modifying the OE x-member to retain the exisiting trans mounts, but to facilitate the installation of two small tanks on either side of the trans, and under the exisiting floor height. This will require lots of plumbing, but approximate as close as possible the OE weight distribution.

More to come!

Geo

Nice work John.

What do you think the feasibility is of cutting out the rear seats and having two cells fill that space? I know the shape would have to be customized to have sufficient space around the gearbox, but with two lines out of each cell combining underneath the chassis I think it ought to work but I just don't have the time to pursue that right now. You already have a bulkhead above the seats and that's all that would really be needed.

What capacity are you shooting for?

RedlineMan

Geo;

As you can see, mine is gutted in that area already. If I recall, there isn't much except brake and fuel lines that need to be reconfigured there. Of course the ever-present torque tube and shift rod are unfortunately prominent.

I know that there is at least one car with a custom cell that sits in this area. I guess it might be possible for one or two cells to sit there. The real problem is that no one makes a standard tall/narrow cell. You would have to buy an expensive ATL or Fuel Safe horizontal cell and then convert it to vertical. That would add a not inconsiderable expense (maybe $2-300) to an already expensive part ($650 for the cheapest model!).

I have not settled on size yet. I do indeed love the fact that my Old Beast can go all day on a tank full. One less thing to have to do in a busy day at the track. If I use a single it will either be 16 or 22. If I go double, it will be between 8s and 10s most likely. Whatever fits whichever config I settle on!