Fuel cell install with CIS-E..

[Rabbit05]

Hi all,
I am looking into doing a fuel cell in my Audi, running CIS-E. I was wondering if I could ask a few questions to the "been there done that" crowd. The car I am building, due to the cage in in requires I put a cell in it. The stock tank wont go..

I am looking at the ATL sportsman 12 Gal cell (pt# SP-112). Will the two fittings be ok for CIS ? I Know that the cell needs a vent , the pick up , and someplace for the return fuel line to go....


From what I have dug up.. the basics of it is this....

Cell--> filter-->external pump--> then to accumalation can--> Stock pump and filter--> to fuel distributor.

I figure the return fuel line can go back to the accumilation can ?

Any help is appriciated....pics would be awesome ...!

Thanks,

[Lael Cleland]

I am looking to do the same thing to my rabbit & will be watching this thread... One thing I know, you do want to run the return to the acc... Also I was planing to use a lift/pre pump in the tank...

[jimbbski]

Depending on the design of the cell you can use an external feed pump to the stock CIS pump or you can get an internal feed pump if the cell design allows you to install one. Do run the return line to a point between the feed pump and the CIS pump. You can run the return line to the accumulator but you need to have a check valve in the line so that fuel doesn't get pushed back up the return line if the pressure in the return line were to drop.

[Flyinglizard]

I use two , vertically mounted, three fitting fuel filters. Low pressure pump into the first filter, above the high pressure pump. The return line into another three way. The bottom line of the return filter leads to the third line of the primary filter.
The last open line retunrs to the tank.
I have never tried not returning to the tank. The factory always tries to keep the fuel cool, by returning to the tank. MM

[S2_ITBVW]

Trying to do this myself sounds like a good way for me to screw-up my car. Me thinks I may be calling in the professionals for this one.

This is just not clear to me.

However, I am going to have a cell in the car before the next race one way or the other.

[shwah]

Why do you need a cell?
The stock A2 tank is safe, light and mounted in a decent location. It works so well you would think it was OEM...

[S2_ITBVW]

I guess I assumed that maximum safety would be achieved using a fuel cell. I am not interested in being involved in a "fiery crash."

I would, however, be interested in other opinions about how much adding a fuel cell will increase safety.

Thanks!

[shwah]

These cars are safe enough with the stock tank to have an exclusion from the fuel cell requirement in Prod class.

[Joe Camilleri]

In my HP Scirocco I tried to copy a factory installation. I used an ATL cell with three ports; vent, return and out. Out goes to a Facet low pressure pump. From the Facet to a mid 80's Golf high pressure pump that comes inside a plastic box accumulator. Outlet from there to CIS. Return from CIS to accumulator with overflow back to cell.

[Rabbit05]

Ah now I get it...thanks for the pic Joe !
I have two of those Golf assemblies that came with my car ....and I am looking at them saying..I've never seen this on an Audi before. Of course they are hidiously rusty, BUT, now I know what they are .

Thanks Joe..

-John

[Flyinglizard]

Be very careful wi th the plastic box. The three screws that hold in the pump can break the box if over tightened. Get a new pump seal O ring .
The box cost about 80- 90$ the last time I sold one.

[S2_ITBVW]

I called the SCCA and asked them about the relative safety of a modern (sort of, my car is a 1987) stock fuel tank vs. a fuel cell. They said that they conferred with automobile manufacturers/safety folks who said that modern fuel tanks are very, very safe. For example, my Jetta's tank is made of flexible plastic. It is positioned over/near the axle beam within the frame of the car. Essentially, it is going to take a whole bunch of force to contact it, and if something does make contact the tank will likely bend to absorb it. On the other hand, any fuel cell that is installed will have to be positioned behind the current (i.e., more protected) position of the stock fuel tank. This position puts the fuel cell directly in the crush zone of the car. So, even though the fuel cell itself can withstand more trauma, it is going to be positioned in a place that could possibly subject it to MAJOR impact that might exceed the capabilities of the fuel cell anyway. This is why they allow the stock fuel tank in production. There is no guarantee that a fuel cell is always more safe than a modern stock fuel tank.

FWIW, I am not going to rush out to the store and buy a fuel cell today. I am going to go home and look at the stock tank and really think through how the thing is positioned and how safe it seems to be. I suspect that I may decide to leave the car in its current configuration and feel like I am still being thoughtful and safety conscious.

[Ralf]

Since you have a Jetta, you have even more of a crush zone then my Golf. And think about this, how many times have you seen a crashed car either in the junk yards or on the news and the cars didn't erupt into flames?

[Flyinglizard]

I bought back one of my old cars, post wreck. 85 Jetta 2 dr. It was hit so hard in the rear that the windsheild broke.
The crush zone /bumper was moved about 20in.
I put that tank into another car.
Stock is very safe.
You can run into interference from oversize tires rubbing it , on the pass side filler area. I paint the plastic so thatI can see if a set of wheels hits . You need about 3/4 in clearance, if you are running the DRS system, (totally worth it BTW)
Same goes with blowing that RR tire, pull over right away.
MM

[GTIspirit]

or on the news and the cars didn't erupt into flames?

Is it just me, or in the movies do the cars seem to erupt into flames just before they impact the ground?

And yes, I agree with the statement that the A2 plastic fuel tank is well designed and mounted in a protected location. Plastic fuel tanks are surprisingly strong and resilient in crashes.

[jimbbski]

Is it just me, or in the movies do the cars seem to erupt into flames just before they impact the ground?

No it's hollywood not you! Some people tend to believe everything they see in the movies and I have seen where they get all worked up at an accident expecting the car to blow up! It doesn't dawn on them that they don't really read many stories about perple dying in fiery car crashes if it happened as often as it did in the movies.

One of the safest stock fuel tanks I know of is what came in the Capri Mk I. It has a higher center of gravity but it was out of the way of almost any accident you could think of. I remember that the safety nazis used it as an example of safe design compared to the location and design of the Pinto fuel tank and both from the same company.