Internal vs external Fuel pumps and surge tanks
 

Hey guys, I posted this in the 3rd gen section and didn't really get any replies so I decided to bring it here.
Basically I've got a Fuelsafe fuel cell and I'm wondering if I should run my pumps internally or externally ( 044's ) and if so which is better an internal surge tank or one mounted in the rear hatch area. This is on a dual purpose build part street , part auto X . it's almost certinaly overkill, but it's the route I've taken, so I have to see it through. Any pics, suggestions or advice will be greatly appreciated. Thanks .

I run a massive fuel pump externally. i've sumped my stock tank. so when i have less then 1/4 tank i can cause starvation at max lateral G during road race. with a decent fuel cell you shouldn't have this issue. for autoX surge tank is way over kill

As far as the need for a surge tank, it depends on if you're going with injection or carbs and how much fuel you expect to be carrying when you. With fuel injection you can't stand to suck any air... especially in autox where microseconds count for a good run. If the tank isn't full of fuel I don't see how you can get by without a surge tank... even in a cell with foam the fuel is going to be sloshing around and uncovering the pickup.
As far as your original question: Check the rules of the organization where you plan to race. I'm not sure what you mean by "in the rear hatch area" but most sanctioning bodies strictly prohibit having fuel systems mounted in the passenger compartment. So you should at least have it boxed in with tin if it's going inside the car. Other than that, I don't think there's any real advantage to one or the other method. If fuel capacity isn't an issue, personally I would put it all inside the cell just to get it hidden from view.

I run a Ford truck pump externally with a box inside the cell to trap fuel. I built a box with three one way doors and placed it in the back of the cell. You can buy them from ATL and Fuelsafe but I'm cheap and have the facilities to build my own. I also bring the fuel return back into the box inside the cell.

Slevin...
I've run a stock tank with an external swirl pot and this worked fine. However, the extra plumbing and the need for a second fuel pump is a bit messy. Note that if you run with a swirl pot in SCCA you will most likely need to install a sealed vertical wall to pass tech (check your rulebook).

Currently I am running a fuel safe cell with an internally mounted sump with the 044 pump. This setup is cleaner, more simple and runs only a single fuel pump. The downside is that the internally mounted sump with the 044 pump is nearly $1000.

If you do decide to go with a swirl pot, I have one that is lightly used...:nod:

Guy

https://lh3.googleusercontent.com/_O...0/IMG_1307.JPG

I like your setup. I was leaning towards fabing up something like this. and mounting it on top of my fuel cell. Right now I'm SCCA, but some day I want to get serious and start running in different "leagues" and higher classes.

I ran a sumped oem tank about 2.5" down and ran a A1000 externally of course I had put foam baffles in my oem tank but it worked great on and off track.

I thought about buying a sump. Not really sure what I think about it on an FD though haven't seen one with a diffuser yet.

well in that case the diffuser will definately hide it, My fc was sick man if you stood behind you could see the lines and pump .
Attachment 722930

See I like that. Always did like the back of the FC ( probably the duals) But yea I might go this route it's cheaper that for sure.

I run a sumped fuel cell with twin 300lph external pumps. I haven't had starving issues yet (*knocks on wood*) with only foam in the tank.

Stupid question but how do I foam the tank and where do I get said foam from. My understanding was that foam melted in gas and led to basically jellied gas. But I'm new to all this, so best to ask questions.

Fuel foam - we had that problem, last engine leaned out & dropped rear apex seals & housing - we checked everything, found a gel like substance in the fuel cell, first time out with new cell & foam (RCI cell & foam they supply), we opened the filter, almost solid with this gel, clear fibre junk.
We did a 2 hour test/tune before race day - car fine, race day - car started ok, in qualifing 10mins in we lost the rear rotor & turbo, huge lean out at end of front straight @ 7800rpm.

I wont be using foam again - baffle the tank or use a trap door pot along with the external lift pump to the 2l surge tank & Sx pump/filters.

The main game cars here use the "black" ATL stuff which seems to stand up to E85 - even then, if you think it's an install and forget, that's not the case - usually replaced after a year or so.

Usually come across foam debris after initial install and cutting up the bricks and stuffing them inside, so you have to check socks and filters for the first few meetings.