Fuel Cells - If you knew then, what you know now

[tneker]

With the recent changes to the rules regarding bulkhead requirements, I imagine more than a few folks would have installed their fuel cell a bit differently.  We are at the very beginning stages of a build so we have a clean slate.

 

From scouring the forums from previous posts, it would seam like there are two schools of thought.  One would be that the cell can be dropped in the trunk where the spare tire usually is, surrounded by a steel tube frame.  I will call that option A.  The other viewpoint being that you should not put it there in the event of hard rear impact, but instead push forward (and upward) between the rear towers.  I will call that option B.

 

A somewhat unscientific listing of the pro's and con's of each approach:

 

Option A - Completely within the trunk, deep within the spare tire well.

• Easy to accommodate the bulkhead rule - Pro
• Weight down low (CG) - Pro
• Weight farther back as compared to stock tank - Pro or Con?
• If you are willing to pop the trunk lid for refueling, probably pretty easy to still use clear tubing for inlet to aid fueling without spilling - Pro
• Cell location more susceptible to impacts that could cause deformation / damage to the fuel cell - Con

 

Option B - Between the rear towers, up higher for differential clearance, pulled to back side of seat tray.

• Accommodating  the bulkhead rule would likely require fab for tunnel for fuel filler inlet - Con
• Weight would be higher (CG) - Con
• Weight would be farther forward closer to stock tank location - Pro or Con?
• Cell location may be less susceptible to impacts that could cause deformation / damage to the tank. - Pro

 

My fairly short list of pro's and con's would seem to suggest that if you trust a FIA cell can withstand any type of impact likely to be seen in Champcar you may be best to go with Option A.

 

Ready, set, debate.............  Extra points for pictures (I'm a visual learner)

 

Edited September 12, 2019 by tneker

[cagedruss]

I've installed  30 cells over the years. 27 of them hanging in the trunk floor. 1 of them in the back seat floor of a Volvo 240 and 1 in the passenger side floor board. Number 31 will be mine and well be installed in the passenger side floor board also with a sheet metal enclosure. 

 

Many have of the cars have been shunted in the rear with no issue for the cell. Get it as close to the diff as possible.

 

Only pic on my phone is from a Grand Am car I built a few years back. 

[cagedruss]

The discriminator valve was added at the customer shop with proper tubing and vent. 

[hotchkis23]

Good topic to discuss, I think @red0 can share pics of his impact at Road America and how well his cell held up with the entire rear of the car pushed forward.  Ours are in the "Option A" area as you state.  We have had two hard impacts to the rear/side that could have compromised the cell and did not.

[DRVOLKS]

Fuel cell install is just the beginning. Fuel pumps, pickups that work, surge tank that work , Fuel lines and layout,  fuel filler location , Vent line location and fuel spill. It takes a lot of planing and reading on the site to get it close.  

www.DRVOLKS.com 

[Black Magic]

12 hours ago, tneker said:

With the recent changes to the rules regarding bulkhead requirements, I imagine more than a few folks would have installed their fuel cell a bit differently.  We are at the very beginning stages of a build so we have a clean slate.

 

From scouring the forums from previous posts, it would seam like there are two schools of thought.  One would be that the cell can be dropped in the trunk where the spare tire usually is, surrounded by a steel tube frame.  I will call that option A.  The other viewpoint being that you should not put it there in the event of hard rear impact, but instead push forward (and upward) between the rear towers.  I will call that option B.

 

A somewhat unscientific listing of the pro's and con's of each approach:

 

Option A - Completely within the trunk, deep within the spare tire well.

• Easy to accommodate the bulkhead rule - Pro
• Weight down low - Pro
• Weight farther back as compared to stock tank - Pro or Con?
• If you are willing to pop the trunk lid for refueling, probably pretty easy to still use clear tubing for inlet to aid fueling without spilling - Pro
• Cell location more susceptible to impacts that could cause deformation / damage to the fuel cell - Con

 

Option B - Between the rear towers, up higher for differential clearance, pulled to back side of seat tray.

• Accommodating  the bulkhead rule would like require fab for tunnel for fuel filler inlet - Con
• Weight would be higher - Con
• Weight would be farther forward closer to stock tank location - Pro or Con?
• Cell location may be less susceptible to impacts that could cause deformation / damage to the tank. - Pro

 

My fairly short list of pro's and con's would seem to suggest that if you trust a FIA cell can withstand any type of impact likely to be seen in Champcar you may be best to go with Option A.

 

Ready, set, debate.............  Extra points for pictures (I'm a visual learner)

 

 

I would try to put it in the stock neon tank position (under rear seat). If exhaust to cell clearance is an issue make a new "tunnel) on right hand side of floor and route exhaust further offset to one side. 

 

The spare tire well with a jaz fuel cell is easy to fab, but can limit your rear suspension options. 

 

If you really think you need it for safety, sure do a cell. A well engineered plastic neon tank should give you close to cell pump out (what it delivers, not holds) capacity with alot less $ and headache.

 

Of the handful of neon teams i have helped the, 2 with cells both had multiple races with fuel delivery issues. Besides poor vent placement (yes you need a float valve and or separator box (evap can has this function), i have yet to see a stock neon tank have problems. 

Edited September 12, 2019 by Black Magic

[Davef_dci]

I'm contemplating a build and curious about this issue as well. Beyond the Neon to Tneker's question - in general - are Fuel Cells "safe" if they are installed in the spare tire well area or are they too prone to fires in the event of a rear end collision.  It seems like the spare tire well is the easiest place to put the fuel cell but it's also right at the back of the car.  Is it meaningfully safer to locate the fuel cell further forward in the car?  Any history here or are the fuel cells robust enough to survive a meaningful impact at the speeds we run.   

[EngEtan]

I'm building a car as well and have debating locations for a cell as well. I like the idea of having a fuel cell in front of the rear axle to reduce the polar moment of inertia, and obviously the lower in the car the better, but you also need to consider the overall balance of your car. Will moving that weight forward (or in your case, aft) upset the balance of the car? My car has the factory plastic tank located behind the rear axle, so this is something I'll have to figure out if and when I decide to go to a fuel cell. In your case, I'd probably locate it in front of the rear axle, similar to where your stock on is located.

[DRVOLKS]

I have installed a few cells over the years . on our Audi TT we installed it behind the driver close to the stock location in the center of the car. the location is very important more centered the better. If you move up to scaling the car it will help you to dial the car in faster and  spread the weight out.

Here is the first cell install 

[mender]

Anyone who watches NASCAR knows where they put their cells ... Option A.

 

I went for option C for my Fiero: passenger's side of the car behind and tied into my NASCAR door bars. At the time, I conferred with my regional tech director to make sure that it would pass tech, which of course it did - then. The fuel filler hose and the vent hose are open to the driver's compartment, and I had no problem with that given the location of those hoses and some tests that I did with used ones. You can see the layout here:

 

Adding a piece of tin around the hoses does very little to protect them, since anything rigorous enough to breach the hoses would do the same to the metal enclosure.

[Andrew D Johnson]

On 9/11/2019 at 8:27 PM, hotchkis23 said:

Good topic to discuss, I think @red0 can share pics of his impact at Road America and how well his cell held up with the entire rear of the car pushed forward.  Ours are in the "Option A" area as you state.  We have had two hard impacts to the rear/side that could have compromised the cell and did not.

 

 

 

[tneker]

11 hours ago, red0 said:

 

 

 

If I am remember a previous post correctly, @red0 weren't you a proponent of not putting the cell in the trunk based on what your car looked like after this incident?

[Andrew D Johnson]

19 hours ago, tneker said:

If I am remember a previous post correctly, @red0 weren't you a proponent of not putting the cell in the trunk based on what your car looked like after this incident?

 

When possible, like in most FWD applications.

[hcsi99]

 

 

 

First off, that is not a pizza oven or a wood burning stove in there.  I had already removed the back seat and package self structure before the "everything must be enclosed in metal" rule came out.  We had hopped to install it where the back seat was, but it was to tight to get the cell in with the cage already installed so we mounted it above the rear axle in a steel frame bolted to the frame of the car with grade 8 hardware and wrapped fuel cell cage with sheet metal.  Enclosing the cell was not a big dealer, but enclosing the fill tube, vent tube, and fuel filler pocket overflow tube took some work and wasn't complete until the Thursday before Gingerman after a few failed attempts with different ideas.  We ended up using 5 inch semi exhaust tubing for the filler tube cover and had no trouble passing tech. 

Our fuel cell is roughly 8 inches higher inside the vehicle than the factory tank that was under the car, behind the rear seat bottom, but in front of the rear axle. This didn't seem to causing any crazy handling issue at any fuel level.  The weight distribution is 51% front, 49% rear, with driver and a half tank of fuel.  

 

The bad:

We had only ever filled our car without the fuel filler covered so peaking in the back window and watching for the fuel to come up the filler was the way we new to stop.  Our fuel cell vent runs up along side the filler neck and then back down and out  of the bottom of the car.  It was never a problem filling the car, and we never had any issues with fuel coming out during or after filling once we hit the track.  After enclosing the filler with metal we could no longer see when the cell was full and quickly learned on Friday when we filled the car for the race on Saturday that this was a problem.  I started filling the car and heard the sound of liquid hitting the ground, but it wasn't coming out of the filler neck, it was coming from the vent.  It appears that once the tank is full that it fills the vent line first then the filler tube.  This results in roughly a half of a gallon of fuel spilling out of the vent.   This is when I learned the difference between a roll over vent valve and a discriminating vent valve.  We made some modifications to our vent and relocated the hose to a safer location to easily catch the over flow during refueling and lived with our situation but it was not ideal to have a half a gallon of fuel leak out even if it was into a container under the car.  

 

The everything must be enclosed in metal rule:

What brought this on?  Did something happen that caused this rule to be added?  Like many others have said, this seems to make servicing and inspecting fuel lines, filler lines that much tougher.  If you can't service or inspect the lines easily and the line fails fuel is still going to leak somewhere, maybe not inside the vehicle, but somewhere.  How long is that fuel going to leak before its noticed?  If its not inside the car, it's outside the car and probably near something hot.  As stated above, our likely hood of spilling fuel went up 100% during fueling now that we can't see that the tank is full.  Added a port hole with the approved fire resistant lexan isn't going to let enough light in for us to see that the cell is full either.  My other concern is that 5 inch metal tube and what happens when that side of the car takes a hit in a car to car collision or a roll over?  I can't help but think that steel tube is going puncture the top of the tank and cause a larger leak than if it was just the filler neck popping off witch is going to happen anyway with or without the steel tube.   I'm all about a safe race car, but to me it seem that this rule could potentially be more dangerous than the way it was before.  If anything, maybe remove the filler neck needing to be enclosed and add a mandatory fuel filler discriminator valve for cells inside the drivers compartment?  

 

What's next for us:

We plan on adding some type of quick connect overflow solution to the rear of our vehicle and rerouting our vent line so that overflow is minimal and contained in the overflow container.   

 

I did a lot of research on fuel cells and installation before finishing our car and felt that there seems to be a lack of information for our particular series on how to do things the correct way, safely.   I would encourage tech or someone much more knowledgeable than myself to add some diagrams for proper fuel cell venting to the rules page.  Maybe a document on how to prevent overflow and spillage including accurate descriptions of parts required to make your fuel cell safe(er) could be added to the web page like the how to pass tech sheet was.  

[mender]

Kind of reminds me of when small towns start putting up new stop signs and speed limits based on "concerned citizen committees" rather than recommendations from traffic engineers.

[snowman]

2 hours ago, hcsi99 said:

 

The everything must be enclosed in metal rule:

What brought this on?  Did something happen that caused this rule to be added? 

 

We likely brought this on.  Our filler hose burst and allowed fuel to spill. My brother was badly burned and very lucky to survive.  With a better barrier, I believe the fire would have been contained, at least long enough to get him out of the car with minor to no injuries.  

 

2 hours ago, mender said:

Kind of reminds me of when small towns start putting up new stop signs and speed limits based on "concerned citizen committees" rather than recommendations from traffic engineers.

 

Mender, I have a lot of respect for you and think you have great insight into most issues.  In my opinion though, this wasn't a "concerned citizen committee" making stuff up to coddle a generation (my words on the coddling comment, not yours).  It was a real life issue/accident that played out on track at a ChampCar event.  So I'm happy to be the source of inconvenience to every team in ChampCar if it reduces the risk of another family going through the hell we did over the last year.  I'd give my left arm to give him 10, even 5 more seconds to get out.

 

Drivers, fuel and fire are the three most dangerous things in our sport.  In my opinion, its best to keep the three separate whenever possible.

Edited September 17, 2019 by snowman
spelling/text

[Gkuhn41]

2 hours ago, hcsi99 said:

We plan on adding some type of quick connect overflow solution to the rear of our vehicle and rerouting our vent line so that overflow is minimal and contained in the overflow container

 

This is what we have on ours, we have 2- 3/4"vents 1 with a  dry break quick connect for overflow, one with a discriminator to vent. Radium makes a 3/4" in cell discriminator that is pictured, i would not install that we had problems with it still spitting out fuel while filling. They also have a external discriminator that works flawlessly it will burp about 2-3 ounces out on us once it is full. But seals after.

 

If you are not diligent with the hunsaker you WILL overflow out the filler so on our last jug we just slow down  a tic and it isnt a problem. Once the cell is full, it will overflow out the 3/4" overflow and into a fuel can we have on the ground. Once done you disconnect the overflow close the cap and move on.

 

One Caution i would have is, DO NOT fill the cell full until just before the race. If it is full and the discriminator is closed it WILL pressurize the tank. We have monitored this very closely and have had no problems with fuel pressurization at a pit stop but if it sits for 30 minutes PACKED full it can pressurize.

[mcoppola]

@snowman I'm truly sorry for what your brother and your family had to go through. I remember the story, and commenting on it once before. Many of us (me included at times) have voiced concerns about whether the 'cover everything rule' is indeed safer.

Thank You for chiming in here and bringing up an example where boxing everything in would have been beneficial to the drivers' safety. It's unfortunate that anybody had to endure that situation in order to drive this rule change. Is the rule - or each teams' execution of their fuel system installation perfect - before or after the new rule? Probably not, but just like I stated in the Flagtronics box thread - I truly believe that Tech, BoD, and ChampCar management are studying cars and situations, trying to learn from them, and making rules that will hopefully keep us all safer.

I hope that Travis is recovering and your family can somehow, some day put this unfortunate event behind you. In the meantime, it was great watching the post race interviews and video from Thompson - seeing you get back into the drivers seat and enjoy some success with @Ronh911's team there made me really happy to see just how much you enjoyed it.

[cagedruss]

Never mind

Edited September 17, 2019 by cagedruss

[hcsi99]

1 hour ago, snowman said:

We likely brought this on.  Our filler hose burst and allowed fuel to spill. My brother was badly burned and very lucky to survive.  With a better barrier, I believe the fire would have been contained, at least long enough to get him out of the car with minor to no injuries.  Drivers, fuel and fire are the most dangerous things in the sport.  In my opinion, its best to keep the three separate whenever possible.

I do recall hearing about a driver being badly burned and I'm so sorry for what your family has gone through.  I'm curious to know more about what happened in the interest of knowing what I can do to help myself and my team be safer.  I always thought it was ironic that someone had to be seriously hurt or killed in Motorsports before rules got changed, but I guess you can't always predict what could happen until it does.  @Snowman if you prefer to not discuss the event on the forum publicly or not at all, I completely understand.  

[Gkuhn41]

20 minutes ago, cagedruss said:

Only way the discriminatory valve is closed its because the cell is over full or the valve is to close to the cell.

 

Correct, given our install the valve is too close to the cell, and that is why i gave a warning if they are going to follow our install.

 

Jay and I discussed this subject. The correct thing is to run our overflow how we have it (or similar), and have the discriminator away from the tank and above the overflow. (and we may try and do this with what we have move it away from the tank some and fabricate a mount.) Problem with that is most the decent discriminators are 1" or larger and the rules state max 3/4" vent. So this limits the selection of discriminators. We chose the one we have because of how clean the install was going to be.

[snowman]

31 minutes ago, mcoppola said:

@snowman I'm truly sorry for what your brother and your family had to go through. I remember the story, and commenting on it once before. Many of us (me included at times) have voiced concerns about whether the 'cover everything rule' is indeed safer.

Thank You for chiming in here and bringing up an example where boxing everything in would have been beneficial to the drivers' safety. It's unfortunate that anybody had to endure that situation in order to drive this rule change. Is the rule - or each teams' execution of their fuel system installation perfect - before or after the new rule? Probably not, but just like I stated in the Flagtronics box thread - I truly believe that Tech, BoD, and ChampCar management are studying cars and situations, trying to learn from them, and making rules that will hopefully keep us all safer.

I hope that Travis is recovering and your family can somehow, some day put this unfortunate event behind you. In the meantime, it was great watching the post race interviews and video from Thompson - seeing you get back into the drivers seat and enjoy some success with @Ronh911's team there made me really happy to see just how much you enjoyed it.

 

Thanks for the well wishes @mcoppola.  It was a tough road, but he's doing really well now.  He was actually supposed to race our vintage sportsman over the weekend, but the power steering box failed on one of his practice runs and they didn't have a spare (pic from the weekend below).  We're working on a build now for Thompson 2020.  Being at the track that week, and seeing the smooth operators of Visceral Racing Group, really rejuvenated him.  He's been applying the pressure on me to build another car about every day hahaha. 

 

I'm 100% with you on "cover everything" rules.  And I've questioned them too, Flagtronics included.  Money and time are major barriers to entry in motorsports, so I totally understand when people take issue with anything that eats into one or both.  ChampCar, BoD, Tech....they're in a tough spot.  While I don't always agree, I do think they're operating with the best intentions.  Sometimes its difficult to save people from themselves, and you piss a lot of people off.  

 

@hcsi99 happy to talk.  I'll send you a message.

 

 

[mender]

1 hour ago, snowman said:

 

We likely brought this on.  Our filler hose burst and allowed fuel to spill. My brother was badly burned and very lucky to survive.  With a better barrier, I believe the fire would have been contained, at least long enough to get him out of the car with minor to no injuries.  

 

 

Mender, I have a lot of respect for you and think you have great insight into most issues.  In my opinion though, this wasn't a "concerned citizen committee" making stuff up to coddle a generation (my words on the coddling comment, not yours).  It was a real life issue/accident that played out on track at a ChampCar event.  So I'm happy to be the source of inconvenience to every team in ChampCar if it reduces the risk of another family going through the hell we did over the last year.  I'd give my left arm to give him 10, even 5 more seconds to get out.

 

Drivers, fuel and fire are the three most dangerous things in our sport.  In my opinion, its best to keep the three separate whenever possible.

My apologies.

 

I've been dealing with some of those committees in our town lately so made the parallel. I wasn't trying to be insensitive and I'm glad your brother is doing well. If you're willing, I'd like to hear more details on the failure mode.

 

I feel that hiding a problem and making a potential issue harder to tech is the wrong way to do things. I've seen too many rule changes in other series that were instant reactions to a situation and implemented with good intentions but not always with the expected result. 

[snowman]

We're all good @mender.  I truly understand where you're coming from.  That's part of why I said  it was my opinion it would have helped, as I'm certainly not an expert.  There are multiple ways to solve every problem.  Good intentions don't always yield proper results.  One of the benefits to having such an involved member base, is that the issues can be discussed and reviewed when needed.  Personal experience just happens to make me a strong proponent of this one.  

[DRVOLKS]

We to have had some trouble with the enclosed filler and the vent tube leaking after filling . we relocated the the filler on the drivers side up high in the C piller on the TT so it had a good downword slope. and run a metal 1/2 vent tube out of the cell encloser  up higher then the filler and back down out the bottom of the car under the filler. we use a long big od jug hose. when filling with the hose in all the way in the filler last can when it spits back drop the jug and pull it out. with luck it may spit on one turn . When we run Lemons we use the certified safe clear reinforced filler hose at $35 ft and stop filling when we see the fuel start to come up using the clear hose we never have it leak on to the car unsafe, and never leaks on the track .