re: casc fuel cell rules...

[ADAM]

hi guys,
i am installing a fuel cell,
i built a fuel can out of the specified material, and have sealed the fuel can with a lid as well, so that the fuel cell is totally sealed inside the fuel can....and has no contact with the drivers compartment

my question is....mounting to the car...i have used 4 metal brackets with a total of 24 rivits to hold it onto the car and fuel can....

is this good enough for casc?

do you guys have any pictures or suggestions of the correct way to fasten the fuel can to the car?

i have a few people telling me the rivits are not strong enough, though i don't think thats the case since they have a very high sheer force before they are ripped free...

help...

thanks

[ADAM]

here is a pic of what exists right now...



http://www.turbo240sx.ca/fuelcan7.jpg

[rmicroys]

What sort of bladder are you running in there?

[ADAM]

http://www.turbo240sx.ca/fuelcan9.jpg

[rmicroys]

Why would you not have actually gotten a more square cell and actually made a box, cut the floor out among other ideas? Just curious about the choice of that cell, because it really raises your cg and puts your fuel much further back in the chassis.

I'm putting a cell in as well, but I have removed the spare tire well entirely, am building a angle and box steel frame, then encasing the bladder in a Al box. Good luck finding a good method to hold your box. I'd use grade 5 bolts and not rivets. Certainly not blind pop rivets. You could use structural rivets, but that is a lot of work.

[ADAM]

i am using this cell for the very reason its not under the car...i can build a diffuser with the correct angles using this type of fuel cell...which will GREATLY offset the slight raise in C of G, due to the downforce it will create..

i guess i will just weld the brackets down then....then that will make everyone happy..

[rmicroys]

Well... I find that hard to believe that you can't build the diffuser under the fuel cell back there. The angle on the diffuser shouldn't be more than about 4 degrees to keep the drag coeff down. Also, the fuel cell requires AT LEAST 6" of ground clearance, but diffusers lose effectiveness after getting more (and especially if they start with more) than 4" of clearance. I also assume then you are going to flat bottom the car and how is it?

[MightyMouse]

You are going to have a lot of problems getting that through tech. You are using shelf brakets to support it:eek:

To be honest, you would be MUCH better off running the stock tank compared to this.

[ADAM]

Originally posted by rmicroys
Well... I find that hard to believe that you can't build the diffuser under the fuel cell back there. The angle on the diffuser shouldn't be more than about 4 degrees to keep the drag coeff down. Also, the fuel cell requires AT LEAST 6" of ground clearance, but diffusers lose effectiveness after getting more than 4" of clearance. I also assume then you are going to flat bottom the car and how is it?

actually diffusers make the most downforce at 12-14 degrees angle being the max before severe separation starts..yes the car will have a flat bottom, with the diffuser tunnels starting just before the rear differential...

i have not finalized the strake design yet, since i am not sure what i am going to do with the exhaust...i may opt for side pipes, or even integrate the exhaust plumbing into the diffuser section to provide more downforce when on the throttle..

[MightyMouse]

You got much bigger issues than diffuser angles. I wouldn't worry about it.

And any diffuser angle above 4 deg, greatly increases drag. You may have more downforce, but at a cost of much increased drag.

[rmicroys]

Sure you can go to 12-14 degrees but drag is increased significantly. I didn't say that it couldn't be increased above 4degress, I just suggested it for the best d/f:drag...

[ADAM]

ok..what brackets should i use? i can make them out of anything? all it says in the rules is that it must be "securely fastened"... ok so whats "secure" ? i have 24 rivits currently holding it down...and i will weld the rest of it down....is that "secure"
?

thats why i am asking....

IMO by the time those 24 rivets rip out the rear of the car is going to be pushed past the diff...so its a moot point what is holding it to the car..since it will be stuck between the roll cage



Originally posted by MightyMouse
You are going to have a lot of problems getting that through tech. You are using shelf brakets to support it:eek:

To be honest, you would be MUCH better off running the stock tank compared to this.

[malcolm]

I am looking forward to seeing these ground effects... How are you going to shape your splitter? (ie. to accelerate the air going under the car...) This is on a 240SX, right? (assuming by the signature on your posts)

Also, what will your ground clearance be? Any plans for vortex generators to make up for slight errors in design?

Sorry... I love aerodynamics on racing cars. Best site ever: www.mulsannescorner.com :D

[ADAM]

i can compensate with the increased drag by just increasing the power...thats the easy part....

lets get back to the mounting of this can.....how should i strap it down? that would be "secure" per the rules...



Originally posted by MightyMouse
You got much bigger issues than diffuser angles. I wouldn't worry about it.

And any diffuser angle above 4 deg, greatly increases drag. You may have more downforce, but at a cost of much increased drag.

[ADAM]

ground clearance will have to be played with, no plans for vortex generators, from what i am reading they are too complicated to try and design without the use of a wind tunnel...which is way out of my budget to use...

basically it will be a flat bottom out of aluminum, with a nice rear diffuser section....in combination with my large rear wing, and some smaller front dive plates


Originally posted by malcolm
I am looking forward to seeing these ground effects... How are you going to shape your splitter? (ie. to accelerate the air going under the car...) This is on a 240SX, right? (assuming by the signature on your posts)

Also, what will your ground clearance be? Any plans for vortex generators to make up for slight errors in design?

Sorry... I love aerodynamics on racing cars. Best site ever: www.mulsannescorner.com :D

[rmicroys]

Personally, I would have designed a safer cell first and then worried about the diffuser after, rather than dreaming of a killer diffuser and how to make sure you can get 10.5" of clearance at the back of a 42" diffuser. That's assuming you can keep the start of the diffuser 2" off the ground at the axles.

When that fuel cell is full, the only thing holding it in the box is the pop rivets holding the lid on, and the fuel hoses. You might want to think about that a bit more.

I wouldn't want that lid to pop off and have that cell flopping on the ends of those hoses if I were to "go turtle". I'm not sure what you need to do, but certainly get some advice from the scruitineers Dave King, Laurence Polley and others who are likely to do your annual tech.

[MightyMouse]

Originally posted by ADAM
ok..what brackets should i use? i can make them out of anything? all it says in the rules is that it must be "securely fastened"... ok so whats "secure" ? i have 24 rivits currently holding it down...and i will weld the rest of it down....is that "secure"
?

thats why i am asking....

IMO by the time those 24 rivets rip out the rear of the car is going to be pushed past the diff...so its a moot point what is holding it to the car..since it will be stuck between the roll cage

You also have to think what happens if the car flips upside down and is rolling, or lands hard on the roof. That thing is going to come out and kill you.

I would build the support out of 1" square tubing welded to the roll cage.

[slucas]

I'm just thinking out load here, so keep that in mind:D . Using what you have I think I would cover in the whole tyre well with aluminium sheet and cut out a hole for your tank leaving enough material to strech a 90 degree lip that would pop rivet to the can (or forget the lip and weld it to the can)that will cover that gaping hole that you will drop everything from beer to bolts into and should stiffen up the whole issue.You could even get fancy and fill the cavaty with some nonflamable gas proof foam.
What do you think? (I don't like those shelf brackets either)

[ADAM]

hi guys,
do you have thier e-mail addreses? so i can contact them?

or do they look on this site?

note...this is for SOLO 1 ..so there is no car to car impact as well...

also note...rivets have about 350lb min sheer strength PER rivit....

so there are 24 rivits holding the 4 brackets on currently, then 5 brackets holding the tank INSIDE the can, thats another 10 rivets, then the lid bolts have another 10 rivets holding the lid on....the tank with fuel only weighs 101lbs total...

christ i only have 2 bolts holding my battery down...

i can put whatever kinda strap/mounting is required..i just need to know what is required to be "securely fastened" its a bit ambiguous

[ADAM]

the reason i went this way is that this is a hatchback...so if i go your route i still have the filler neck exposed in the cabin....my way its a sealed can...along with the filler neck being sealed as well...


Originally posted by slucas
I'm just thinking out load here, so keep that in mind:D . Using what you have I think I would cover in the whole tyre well with aluminium sheet and cut out a hole for your tank leaving enough material to strech a 90 degree lip that would pop rivet to the can (or forget the lip and weld it to the can)that will cover that gaping hole that you will drop everything from beer to bolts into and should stiffen up the whole issue.You could even get fancy and fill the cavaty with some nonflamable gas proof foam.
What do you think? (I don't like those shelf brackets either)

[slucas]

Part 2: Inside the can use 1" x 1/16" strapping bolted to the floor and bent to fit tightly over the cell. I would use 4 straps;2 going "north/south and 2 going "east/west.You don't want your fuel cell to move if you nose plant into the wall!!
Keep in mind the G-forces involved in a head on crash !!!

[rmicroys]

so there is no car to car impact as well

Pardon?

Oh ya, do you intend on participating at the big Mosport track Solo 1 event this year at all... I'm mostly not afraid of car-car impacts. I've personally met the wall at corner 2. Would never want to be introduced to the wall at 4. Think of that cell, what 12 gallons? Then take 12 gallons, times, 3.4, times 0.8 kg/l, times 2.2 lb/kg... that's a measly 72 lbs of fuel. Now take a 100km/h impact,possible. Assuming that your car decelerates in about 30cm of crush, then the contents of the car is subjected to about 130 Gs. That fuel cell during the crash now effectively weighs a measly 9360lbs. Do you trust rivets?

[ADAM]

ok..so what about welding it in?

what i really want to know..is what is "officially" required

if i have to build a 1x1 box around it ..so be it..or 1/2 steel plate or whatever...

all the the rules say is "securely fastened"

at some point when you hit things..it does not matter how its designed..rivets , welded, straps or not...

my stock fuel tank, used 2 bolts and 2 rubber straps to hold it on only...

[malcolm]

from mulsannes corner:

http://www.mulsannescorner.com/diffuser5.jpg

Ok, pay key attention to the front of the car. a lot of downforce comes from there. It's similar to a wing how the front of the wing creates the most downforce because the air is accelerated the most at that point. If you are going to all that trouble to make a killer diffuser, you need to accelerate the air first so it does something. Remember, a diffuser's aim is to *diffuse* the air back to normal speed from it's accelerated state under the car. It won't create hardly any downforce itself.

...then the contents of the car is subjected to about 130 Gs.

including the driver. I don't know about you, but I think I'd die if I was subjected to 130 Gs. Maybe that's just me. Do I need to work out more? ;)

[malcolm]

oh, and vortex generators are EASY to make!!! From the late Carroll Smith's "Engineer to Win" (RIP): "if testing reveals local seperation, the placement of vortex generators upstream will prevent the seperation without a major rework."

also (if you have the book, refer to fig. 224, page 242):

take a piece of sheet aluminum, 1.38" by 0.75". from the corners of the leading edge, fold them on a 10-12 degree angle to the sides.

.......... 1.38"
_______________
|\..................../|
|.\................../.| ..... 0.75"
|..\................/..|
-----------------

|19|

Like above (ignore the dots... this program doesn't like more than one space). Not sure what the "19" is (maybe 32's of an inch?), so I guessed that it's 10-12 degrees.

That, my friend, is a vortex generator. :D

[malcolm]

ok, here's an msPaint version. ;)

[slucas]

Can we give Adam some more ideas on how to mount his fuel cell?

(home made aerodynamics seems to me to be on a par with do-it-yourself surgery, at some point risk out paces benifit :D )

[ADAM]

hi guys, all the aerodynamics info is great...i actually bought two very in depth books about it..so i am covered pretty good....

i still need a definitive answer on what a secure mounting is....

i was thinking last night...why not just run a metal strap around it mid point and bolt it to the back of the car?

and then weld the 4 brackets down as well as leave the rivets in.

what the picture may not show that well, is that the cell is actually in a deep hole, with most of the cell actually in that hole, so any lateral forces on the fuel can will be placed on the hole....it would be very hard for it to just pop out...most of the hieght on the fuel can lid is just open space that i left so that i can refuel it easy

[rmicroys]

If you can have a couple straps (think similar in size to a OE tank strap) or two across the top of the cell, and bolt down throught the sheet metal of the car with at least grade 5 bolts, with good sized washers to spread load, then you'll probably be a lot better off at tech insp. time. The VW Jetta had three straps holding the tank up in to strong hardpoints on the car. The cell I'm putting in is going to have a full 1" square box steel frame to hold the cell and a couple straps over the top. I would make sure that cell is held down well, and not using the "box" around it to hold it in.

[slucas]

That it is sitting in its own "well" is good, now you want to make sure it won't move if you end up on your roof. It appears the cell has four good sized bolts or studs on the top outer edges,can you utilize those to make a "hold-down"?
I can't emphasize enough how important it is to have nothing flying around inside your car in a crash!!!!!
A number of years ago a sedan racer received dreadful injuries when his battery came loose inside his car while he was barrel rolling,

[RacerRick]

I am glad I don't have a hatchback. I just just mount the cell in the trunk and secure it well. Then all that is needed is a little trunk sealing.

[Brian]

Wow, this thread is famous as it made the big time....

http://www.honda-tech.com/zerothread?id=848172

[DavidW]

Originally posted by rmicroys
[B] Would never want to be introduced to the wall at 4.

Been there...done that...got the limp.

In '75 the guard rail was about 6 - 8 feet off the track.

Adam look at how the cell has been mounted in this Improved Touring CRX

http://www.improvedtouring.com/images/special/crx_build/CRXassm55.jpg

[ADAM]

well everyone has critisism but no concrete way of doing it right....


david,
not sure that crx is any better with exposed fuel lines running thru the cabin...?

[myronx19]

Hi Adam,

What I've seen done is a proper safety cell as pictured, but even CASC wouldn't allow that pictured CRX tank without a cover that completely covers the fuel filler.

From what I recall (it's been a while, and he now has a Viper) what Bruno Buso has in his Eagle Talon is a rear mounted cell, inside the hatch. Directly in behind the driver is a full wall, separating the driver from the rear compartment. In the wall is a lexan window that the driver can look rearwards. From memory, I also recall the Multimatic Ford Mustangs having a rear firewall installed as well, directly in behind the driver. These cars mostly used dry break systems.

It clearly states in the rule book: (2002) 2.4.2 pg 50/51 - Fuel Cells shall not be located in the Driver/passenger compartment., fuel cells shall be installed not less than 15cm/6in from the ground unless enclosed within the bodywork or chassis.

----

2.5.2 pg 50 - Bladders shall be installed in containers fully surrounding the bladder, contructed of .036-inch thick steel, or .059 in thick aluminum. All seams of this container shall be sercurely fastened. In closed wheel cars internal body panels may be modified to accomodate the installtion of Fuel cells provided such modifications serve no other purpose.



The exposed fuel lines aren't a real concern as long as all the fittings are of AN type, and braided or rigid steel lines. The lines may not be rubber if they are within the cockpit, same goes for coolant if you have a mid-engined car.


In your case Adam, I'd build the car to CASC road racing rules, because I bet soon enough, you'll want to race it!! ;). So build it once, rather than twice. I was building my car always with that in mind, and eventually, yes, I went into road racing.


Safety being the #1 priority, if the tank must be enclosed within the cockpit, a separating wall (fully enclosed) wouldn't be a bad idea. It could be made from honeycomb nomex, giving it strength without much support, and can be easily cut for rear main hoop supports. You can make a window that looks outward. Since your car runs fuel injection, the system is under a great deal of pressure, you want to eliminate the possibility of flames propagating to the cockpit in the unlikely event of rupture/accident, etc...


I wouldn't consider that cell mounting as being safe. A roll over would cause that mass to probably rip itself from that container, and worst case is a fire, lesser case, the thing comes forward and hits you.

A square/rectangular container can be properly mounted to the floor, from inside the container. Then the tank can slip in, and install the container cover.

Use foam inside the tank, many benefits for this (it prevents sloshing about).


As far as aerodynamics goes, it is going to make very little difference without a great deal of testing. I don't think we approach speeds high enough to take full effect of aerodynamic aids on GT cars, unless they are full out purpose built cars (like Ken McRae's Laguna, or Ultima, Stealth, etc...)

I agree with Rob, if your car is higher off the ground than 4", a diffuser will not benefit anything other than looks.

A flat undertray made from honeycomb nomex at least 5/8" thick would be a benefit, and a proper splitter/front undertray (going under the engine) to clean and separate the air would also be more of a benefit.

My rule of thumb is: Make the car 100% consistent, 100% of the time, once that is achieved, then add to it. Terry DiFrancesco gave me that advice, so did Graham Tullet, they were right!

But..... that rule will be blown out the window with my next car ;)


so to recap, rules clearly state no cells allowed in the cockpit (however, I've seen them covered, bladder/container and all lines). This is another approach.

You only need a small tank. I run 20 litres for a 30 minute Sprint WOT at 6mpg or so. A larger car will require slightly more fuel depending on the modifications.

Safety is important in any track car, whether it be drag, Solo1/2, track days or road race. Especially with 240sx's.... I have to live with this imprint in my mind at corner 4.

If in doubt, ask a professional.

[Brian]

I'm glad you responded to the Honda-Tech forum. I was feeling bad that a guy would be trashing it openly without offering any help as to the correct, and safe, way to mount it. Bad enough the guy is also from Ontario to boot!

I'm also interested in the answer to your question.

[RacerRick]

Adam, I would mount it like your battery - some heavy all-thread rod right up through inside of the can if there is room and heavy strapping across the top.

Or on the outside and some 1/4" x 1" strapping through small slits in the side and accross the fuel cell. Easy to seal and you can still remove the fuel cell if you have to. Or bend one side to go to the floor and use all thread on the other so you can still slide it out of the cell.

Because the cell fits pretty well in the spare tire well, I don't see much need for the hold-downs to limit its movement front to back or side to side, only to keep it from coming out the top!

The box as shown is pretty common in drag racing hatch type cars with fuel cells.

[slucas]

Adam, perhaps you should get out to Mosport this weekend & tour the paddock .Talk to the guys with fuel cells and take notes, I'm sure they will let you take photos. What you have now will surly kill you if you have a big shunt.
The fuel lines inside the car are a good idea as long as they are steel braided, much better than running them under the car.

It's very difficult to explain how to do this sort of thing in writing, so don't get pissed off at the lack of substance in some of the replies.

[ADAM]

ok...will have to rethink this issue....

hmmm...out comes the plasma cutter :)


what i am really looking for is someone from CASC..that can say...
do this..and this...and this....and its ok....end of story...

[ADAM]

thanks for your input guys....

thanks myron

[slucas]

Chris Capowski was responsable for that cheap shot on the Honda/Acura site. I'm don't think I know him, he's a member of MCO and the chief scrutineer for CASC-OR. Not a very charitable way for someone in his position to act towards a club member looking for guidance on a safety concern.

[ADAM]

yeah you ask for help ..and get kicked in the nuts :) he he...thats the way it goes ..but thats why i posted this..and am asking for help...it can all be changed

i looked at that honda site...through some archives.....a good post there....see below pics....

so what i am thinking now is..... cut a hole in the floor where the wheel well is....just drop the can ...weld it all in place...then weld a sheetmetal cover over the whole back trunk so it completely covers the whole thing....then build a small trap door to refuel the can....then underneath, build up a 1x1 crash box....voila...done....all out of sight and to the rules...



http://www.we-todd-did-racing.com/wetoddimage.wtdr/i=wMTA3NDkzNnM0MTNkZmQzMXk1NDE%3D.jpg
http://www.we-todd-did-racing.com/wetoddimage.wtdr/i=wMTA3NTI4NnM0MTNkZmQzMXk1NDE%3D.jpg
http://www.we-todd-did-racing.com/wetoddimage.wtdr/i=wMTA3NTI5NnM0MTNkZmQzMXk1NDE%3D.jpg

[myronx19]

Say Adam, is there a steel/aluminum container available for that tank you have?

Maybe all is not lost.

If you can find or even build a tight fitting cylinder (steel would be easier) with a welded flange to bolt on the top lid, then you can build a separating panel to effectively house the entire thing as if it were in a trunk.


I wouldn't rely on some of the opinions from the CASC, we are all volunteer's, some with A LOT of experience, and others with opinions. I've seen cars go through scrutineering that I stay WAY away from.... I scratch my head at that, especially after 2002.


However, Gunter Schmidtt is one gent that I rely on to obtain qualified information from. However, there is NO if and or buts with him, the way it is IS the way it is, because he knows what he is talking about. I remember talking about OE tanks with him, and he directed me in the right direction.

Terry DiFrancesco also is quite knowledgable in GT cars (he owns two street cars I'd love to buy from him, but that is another story).

Both gents may charge a small fee but well worth it, most advice is free, but when serious thought is involved, their time is worthwhile.

You can also ask CSC, plastic tanks MUST be enclosed in a metal enclosure, period.

Also, last but not least, if you keep your tank and find an enclosure for it, an expensive but excellent idea would be to fully enclose the tank mounting area with steel or alternate non-flammable material, and then use a dry break setup for remote fuel filling. I think you can even get a non dry break setup, so that it can even route up to your original fuel filler with a postive locking cap.

In the mean time, I'm going to find some pics of rear hatch installations and put them up here, I know I have some.

And slucas, I agree, we should all help each other out here. I know some people have scoffed at some of the ideas I've put out there, but others have directed me along a path into the right direction.

Observing SCCA rules isn't always the best idea either.... There are some things they do there that we are NOT allowed to do because we know better.

(no matter how much I argued, I could not run my targa roof on my car no matter HOW bolted on it was in road racing!!, they can in SCCA, but it isn't allowed here. But, I now see CASC's point, I would never allow it either).


Off to find some info for you (I have to make best of my extra spare time, healing my broken leg).


Oh, and I'm gonna start another thread about seat safety. Boy, I read a lot of crap that people post in other groups about seats, so much misinformation. arghhh.

[myronx19]

BTW:

That tank installation in your last thread would from what I understand it to be "would be acceptable". The bladder is in a metal container, and the filler neck is covered, all is pretty much safe at this point.

The Nascar style cage is certainly safe, but the tank still has to be in a metal container (I don't know if Nascar requires it to be, BUT they don't even wear balaclavas!!, I've even seen the truck series drivers test the Toyota truck without gloves, are these guys on crack?!?, and the Hans device is mandatory, only smart thing they've done).


Now.... If I was to get real picky....

tank location.. vs aerodynamics.

Ideally, a tank should not be in front of the front axle (as a Fiat X1/9) or in behind the rear axle line. Fuel weight changes during a race, which means you can only be setup for one ideal condition, setup for a full fuel load, medium, or empty. In a X1/9, the tank sits almost right on top of the axle, still not a good thing. Ideally, a centrally located tank located or where you need weight (after the car is corner weighted) would probably outweigh any areodynamic benefits on a GT car at our level. 50 litres of fuel is pretty heavy, and having that weight ideally situated really can benefit the setup.

A Renault R5 Turbo 2 has both its tanks right under the driver and passenger seat.

But again, I'm being picky. The ultimate compromise, race a Formula car ;), hehehe.

[ADAM]

i think i am going to go that route...

AND build up a nascar type 1x1 crash box around the cell that will still be enclosed in the fuel can i made..it will just be welded in..and then covered over in a welded sheet plate so the whole hatch trunk becomes flat...then i will install a small trap door to access the filler neck....

ohhh well there is a good 1-2days work for me too do...

but its better that its done right....

thanks myron....

[rmicroys]

Adam, here is a good example of construction of the frame to hold the cell. In this case the old spare tire well was removed, and the frame welded in.

http://members.rogers.com/jettaracer/photos/Dscf0079.jpg

Then a box was made for the lower part of the cell, then the cell should be strapped in on the top, and and then a cover a made. A couple more WIP pictures so you get the idea... the entire box and structure is welded to the car.

http://members.rogers.com/jettaracer/photos/Dscn0369.jpg
http://members.rogers.com/jettaracer/photos/Dscn0389.jpg

[rmicroys]

Adam, another thing, a round fuel cell is just really awkward to work with. I understand the choice to put it in the well, but now that you have the cell... you are very limited in what you can do to properly mount the sucker. Make something that holds that tank good, welded in place except for the last couple of straps that are to hold in down in to place, and then cover it all up well. Good luck.

[rmicroys]

Originally posted by slucas
Chris Capowski <snip> the chief scrutineer for CASC-OR.

Chris is not the 'chief scruitineer' for CASC-OR. Not sure who is the official region's chief, if there is one, but Dave King's name rings a bell, and he does sit on Race Committee I think - or others? Chris C has held a scuitineering A license and was one of the scruitineers for the CGTCC series. I'm not even going near the Honda-Tech post.

[slucas]

Being CASC-OR cheif scrutineer was his claim.

[ADAM]

GREAT install pics....

yes that was what i was thinking....and it would be relitively easy to do......

i will still use the can that i built, cut out the rear tire well of the car, build up a 1x1 crash box like shown..but fitting to my round can, weld it all in..and make a sheetmetal cover so its all sealed up..

should work out great...

re: round cell...yes round is a bit more difficult to work with..but thats what i have..so i will have to work with it...

thanks for the awsome ideas and help...

will report back when i change the design

[rmicroys]

Good luck. Keep us posted, and go to the race this weekend and take a look at the cars, see how they are made. Most production GT cars probably still use their OE tanks though.

[rmicroys]

Originally posted by slucas
Being CASC-OR cheif scrutineer was his claim.

Well, there's a difference between A and THE. He has been A chief @ a race weekend IIRC

[ADAM]

sorry going turkey hunting this weekend :)


the reason i wanted to go with a fuel cell is that i had severe fuel starvation issues with the stock tank, and thats a no no..with turbo cars..




Originally posted by rmicroys
Good luck. Keep us posted, and go to the race this weekend and take a look at the cars, see how they are made. Most production GT cars probably still use their OE tanks though.

[rmicroys]

Originally posted by ADAM
sorry going turkey hunting this weekend :)

the reason i wanted to go with a fuel cell is that i had severe fuel starvation issues with the stock tank, and thats a no no..with turbo cars..
You're talking about fuel starvation due to cornering or delivery entirely?

A 2 litre (or so) swirlpot and two pumps would have been much easier to put in than a whole fuel cell.

[ADAM]

yes.. during cornering, braking accelerating...

i thought about a 2 pump system..and a small surge tank..however i am moving alot of fuel..and would have had to buy two pumps...and they are very expensive...so i figured i could kill 2 birds with one stone and get this cell that is fully foamed and has a 3 door surge tank and 2 pickups in it....

as you can see...the installation of it is harder than i first thought....

funny thing is.....when i first started looking into this...all the fuel cells i saw were just 5 gallon drag racing plastic upright cells....that most of the drag racers just strap down in thier trunks...looked very simple to me...

then i started reading about the casc rules, and since i had a hatchback had to separate the cell from the drivers compartment...ect..ect...


anyway.....time to do it right now....

[rmicroys]

Originally posted by ADAM
yes.. during cornering, braking accelerating...

i thought about a 2 pump system..and a small surge tank..however i am moving alot of fuel..and would have had to buy two pumps...and they are very expensive...so i figured i could kill 2 birds with one stone and get this cell that is fully foamed and has a 3 door surge tank and 2 pickups in it....


Buy two pumps? Eh? If you used your stock in tank pump - under no load it would be able to transfer more than enough fuel for your purposes. You would have only needed to buy one pump for the fuel rail and fab up a swirl pot - that would have only cost you maybe a few hundred $$$.

http://members.rogers.com/jettaracer/photos/fuelsystem.jpg

(gotta love visio)

That would have done you more than adequate. Intank pump to swirl pot, then your killer high pressure pump after the pot to the rail. you would have only needed one pump, as your starvation issues are because the intank pump can't:

A> keep up the volume at the required pressure
B> fuel slosh at low fuel levels.

so either run full tanks when you do your solo events, or do the above. What you are doing is now going to, in the long run cost you much more than what your best solution was...

if you haven't already tossed your OE tank, put that sucker back in, sell the cell, buy a pump (which you probalby already have because of the cell) and get a swirl pot made up... fewer headaches. Have you ever measured the 0 psi flow rate of your stock in tank pump? It's probably pretty darned good, and delivers more than enough fuel to keep the swirl pot full.

[ADAM]

the OEM fuel pump is long gone...during dyno testing it could only support 190rwhp at 43psi..before it ran out of fuel flow....

so i then went to a aeromotive pump that can handle high pressure and high volume..problem is keeping it fed with fuel ..hence the cell....

now that i have the cell..i am going to put it in....i have a week off before the first solo 1 events..so i have the time to install it correctly....

the cell will solve all my fuel delivery problems....and possibly is safer when installed correctly...

thanks for the great input....

adam

[rmicroys]

Originally posted by ADAM
the OEM fuel pump is long gone...during dyno testing it could only support 190rwhp at 43psi..before it ran out of fuel flow....

so i then went to a aeromotive pump that can handle high pressure and high volume..problem is keeping it fed with fuel ..hence the cell....

Unfortunately, you didn't need the cell. That's the issue. Even that stock pump can probably pump the needed lbs/hr to a swirl pot @ 0 to 5 psi. So that's just where it's too sad that you didn't research this properly earlier. The loops you're jumping through now, are crazy just for a SoloI car.

[ADAM]

yeah i am learning that slowly but surely in life....

i must 100% research things before i go guns blazing :)

...but boy do i learn alot through trial and error :)

[RacerRick]

When converting an old camaro to FI we just used a cheap low pressure high volume carter pump to pump fuel to a 1L swirlpot we made out of 3.5", and 2.5" exahaust pipe and some 1/8" plate.

The pump sent more than enough fuel for the 400hp small block and the only high pressure line was the 3 feet from the high pressure walbro pump to the fuel rail. The fuel rails returned to the pot and we simply had a second line out of the top of the pot that was the tank return.

Worked good and I think the entire setup only cost about $300-400 bucks.

I got the idea from Simple Digital Systems website.

[Brian]

This is a great discussion. :)


In the above pics, where do the fuel lines get routed? Are they running through the car in SS lines?

[rmicroys]

Originally posted by Brian
This is a great discussion. :)


In the above pics, where do the fuel lines get routed? Are they running through the car in SS lines?
Yes, you can route fuel through the car in a SS braided hose.

[drpepper]

Just an illustration of the surge tank. I'm going to try and build one this summer.

http://toyotaperformance.com/surge_tank.htm

[RacerRick]

That toyotaperformance.com page is stolen froght from the sdsefi website.

When I did mine I went one better and used a 3.5" tube with a 2.5" tube centered inside. The 2.5" inner was drilled full of 1/4" holes to let fuel pass.

The fuel entered through a fitting in the side of the 3.5" tube and had to flow through the inner tube. Since it was a stock tank with no baffling it sloshed like mad and would areate the fuel. This did a good job at removing the air.