Fuel Cell Frame Design

[SuperDave]

Hey folks!

We at HounDawg Racing are making huge progress building our next race car. Someday in the next four years, we hope to actually see some of you on the track!

While I finish up the roll cage and work on paint and body, I'm planning my fuel cell installation and I have some questions about design for the frame.

I see many examples where you folks have built nice frames that protect the underside of the cell--and there's no doubt that the more protection you have the better. But I don't see anywhere in the GCR or ITCS that mandates any kind of frame for the fuel cell other than the steel casing. You have to keep the bottom of the cell six inches off the pavememt--I assume your frame can hang down lower than that. So unless I'm missing something, as far as the rules go, I have the option of building a big strong frame nestled around the bottom, buying a kit like the RCI-7412A kit (looks like 1 inch by 1/8 inch steel strips that wrap 4 sides in two places), or (not that I'd want to do it) just letting the bare steel case hang down unprotected.

Apart from the rules, what are the design considerations for a safe fuel cell frame? First, I'd guess you want to cradle it firmly in place. Second, you'd want to protect it in case both your rear wheels fall off so the pavement doesn't dig into the cell. Third, the frame can provide some impact/crush protection.

Finally, have any of you running enduros with really big cells had any problems with ground clearance? Some of the 22 gallon cells I see can be pretty tall/deep. I saw an (old circle track) RCI cell, and if I installed it in my 240Z with the top flange sitting on top of my rear deck, it would hang down below the rockers. So if my rockers were 5-inches above the pavement, my cell would have to be raised 1 1/2-to-2 inches to meet the 6-inch minimum. That doesn't seem insurmountable--I guess you just build the frame and cover accordingly, but it seems like there'd be a better way.

Dave

[Ron Carter]

"Panchovillia" <sp> and "Ctompkins" have some great photos their installs. My vintage Z race car has a "Well Cell" in the spare tire well which is another option. See my gallery.

I am a little surprized that you need a 22 gallon cell. Most racecars have 8 to 12 gallon cells, unless you are looking to run enduro's exclusively.

[SuperDave]

I am a little surprized that you need a 22 gallon cell. Most racecars have 8 to 12 gallon cells, unless you are looking to run enduro's exclusively.

I don't know anyone who runs enduros exclusively. If you run an enduro only occassionally, what are you suggesting...take out your 12 gallon cell and put in your 22 gallon cell for the enduro? I'd think that if there's a CHANCE you will run an enduro, you install the 22 gallon cell in the first place. Then for your sprints you just fill it with 8-12 gallons of gas. That's why I'm looking at a 22 gallon fuel cell.

[Ron Carter]

Hey SD, You know, we just don't see enduros on the west coast. No one I know runs such a large tank. Most Vintage events out here are sprint races, so 8 gallons works fine.

It seems what ever you do, your penalized....22 gallon tank is heavier than an eight, and you are limited on where you can put the tank to balance out the weight in the car. An eight gallon tank would not make it for an enduro. So...what to do???

Are you building the car for enduros or sprints? most guys I know build purpose built cars. An enduro is built for longitivity and reliability, and not super high HP. Sprints are built a little more "high strung".

What are you building?

[SuperDave]

most guys I know...

What are you building?

Guess I ain't most guys.

I'm sure you're exactly right that the champions in the sprints have purpose-built sprint cars and the champions in the enduros have purpose-built enduro cars.

But you know what...here's a shocking revelation...it isn't always about being the champion!

I've been around the track enough to know that, given the amount of money I'm spending, I have no chance of winning any races. One of the Atlanta Region board members, who works at my place, told me there was a guy last year who spent $10,000 on one race weekend.

My initial aim is a Solo I hillclimb event--I do have a shot at winning there. But I want to be able to do other things without having to rebuild the car.

My goal is to field a car that is reasonably safe, doesn't oil down the track (or at least doesn't make the corner workers say "here HE comes again"), is reliable enough to finish, and isn't embarassingly slow. I am not an engineer and I am not a Nissan specialist. I am doing virtually all of the work myself. I may be a back-marker. But I'll be a back marker with enough money left in my pocket to buy you a beer after the race! And if I roll my precious Z up into a little ball, I'll be able to walk away with a smile on my face and a zero-balance on my credit card!

[Chino 240Z]

Quick enough to wizz off the guys spending big bucks, good looking enough to be proud of, but affordable enough to keep the hobby a fun thing to do!

Gosh, I would just die if Rons car was ever injured! Don't know if I could take a car like that on the track? I would worry too much about the marbles bouncing of his hood!

Thumbs up Super Dave.

Hey, Ron where & when is your next event?

[Ron Carter]

Dave! Whoa!!

We are off on the wrong foot. You can and will do what ever you want to do...All I am doing is expressing what I see here and having a calm discussion....This is supposed to be fun!! You asked for Ideas, I tried to give you a few...remember I dont have all the details of what you are trying to accomplish...I am trying to understand where your head is at...

From one back marker to another have fun!!

[SuperDave]

Dave! Whoa!!

We are off on the wrong foot.

Sorry, my fault. I'll try to calm down. Your suggestions are appreciated.

[Ron Carter]

Chino, I am having the same problem....I am a little too concerned about running my Z right off the bat...As a matter of fact I am buying a well sorted C Production Roadster to run for my rookie year.

I just can't bear the thought of balling up my Z....too much time, effort and $$$ into that project.

As for my Z, well it will be in Sports Car International Magazine in the next two weeks or so. Sport Compact Car in about April or May and at Motorsport's show in late April.

[Ron Carter]

NP SD,

Let's find a way to make you fast where you want to run and beat a few of those guys with way too much $$$.

I would suggest calling the guys at ATL directly. They were awesome when I called them and made me a great deal on my cell directly from the factory....Be sure to get a cell with a surge tank as they make a really big difference.

There is nothing better than passing a Porsche that has to be worth $100k+ in a rusty ol' Datsun.

[cremmenga]

Just looking through some old post here and was wondering if anyone had any links to pictures the fuel cell frame they used or have seen? thanks

[Ron Carter]

You can look in my gallery of the the ATL well cell that we used in my Z