After fuel starving a few times at the end of a race, it was time to do a surge tank setup. This is what I call my "poor man's" swirl tank setup, I still have the stock fuel tank in place and added a swirl tank setup to it.

Early pic of my setup basically in place (minus the cover I made for it).


The basic concept is that the swirl tank acts as a buffer between the main tank and the rails, providing uninterrupted fuel delivery to the rails even if the main tank pump gets a break in fuel pickup from fuel slosh. This allows you to run the main tank very very low (almost empty based on how good the setup is) before the system will fuel starve from fuel slosh.

The pumps you use, and the size of the swirl tank, all depends on what application you are making it for. This setup was done just to keep me from fuel starving during a 30 to 45 minute sprint race and also be able to run the tank rather low for qualifying without having fuel starve issues.

There are many ways to do the swirl tank setup, but here is a general diagram of how a simple setup it typically done. They only thing missing from this diagram is the fuel filter that should sit between the pressure feed pump and the rails. (found this diagram on the internet, I did not create it):





Parts I purchased from www.jayracing.com for adding the new pressure pump (old pump becomes the swirl tank feed pump):

1 x Fuel Pump Wiring Kit (BFP-WK1)
1 x Bosch Motorsports Fuel Pump Stainless Steel Mounting Bracket (BFP-MB1)
1 x Bosch Motorsports Fuel Pump # 0 580 254 044 (BFP-044)
1 x Golan -6AN Fuel Filter (GFF-6)

Parts I purchased from www.onlinemetals.com for the swirl/surge tank:

1 x Aluminum 6061-T6 Bare Extruded Tube
5" x 0.125" x 4.75" - Cut to: 12"

1 x Aluminum 6061-T6 Bare Sheet
0.125" - Cut to: 12" x 12"

Fittings:
1 x -8an male weld fitting for pressure feed line from tank (*check note below)
3 x -6an male weld fitting for mail tank feed line, main tank return line, fuel rails return line (*check note below)

The swirl tank feed pump was my previous in-tank pressure pump (I think it is the Denso pump that RotaryPerformace sells).

Pic of the swirl tank parts, ready to be sent to a welder:


You can get away with welding the the an fittings right onto the tank, however I choose to make small tubes cut such that it placed the side an fittings at an angle, thus making the fuel flow come in the tank in such a way to cause a literal 'swirl' motion within the tank.

You can find pre-made swirl tanks, like the one in the links below, but it was much cheaper for me to buy the parts and have it welded:
http://www.demon-tweeks.co.uk/produc...LITC305&cc=usd
http://www.sm-engineering.co.uk/allo...surge_tank.php
http://www.merlinmotorsport.co.uk/p6...duct_info.html


*What I would do different:

- use female fittings on the swirl tank with male connection adapter fittings between it and the fuel lines, that way if you damage a male fitting head, you just replace the adapter fitting, rather than having to cut off the male end from the tanks and re-weld a new one on it

- for a level sensor, I tried a few from mc-master car and they were all pure fail, so in the future I plan to add a level sensor like motec sells, part number M P155-CGO-14 in their pdf brochure.

Here is a pic of the cover I made for the setup:


I also attached some pics of other setups I have seen on here.

 

Great write up as usual! Wish I had the time to track one of my FD's like you do.

 

Damian, looks great!

My setup isnt much different than yours. I used some different materials and a manufactured pot. Ive been meaning to get a good write up of how to bend and flare the metals lines and post it in the Fabrication forum but work and sheer lack of a personal computer has prevented me.

I have and can take more pictures but the one below should work for now. It also helps to visualize the pathways of the fuel lines tangibly.

The only change I might suggest with the diagram you posted is instead of feeding the hot return back into the swirl pot, feed it into the oem tank where it could mix with the cooler fuel before being pumped back into the engine. Though there has been debate that since the fuel travels through two pumps that it would generate the same amount of heat, if not more than just using an single pump with pick-up from one large fuel source.

Ill come back later and post more detail about my setup.


Full size:
http://images49.fotki.com/v1460/file...4/IMG_6748.jpg

 

wow thats is a work of art you have going there, I love it!!!

and yes, I agree on the return line change however, that is part of the design, is that the fuel rail return is what is helping keep the surge tank full, if you have it return to the main tank, then the only feed is the main tank feed, and that is the one that can starve, so having the fuel rail return also feed the surge tank helps to keep it full...however, I also do not like the hot fuel going back in there, i am thinking of adding a small cooler in-between, not sure yet.

 

Hmm...

I see what youre saying Damian. The way I have my setup now, is the return from the engine is T'd off right before it enters the oem tank. I figured, that if there was starvation in the main tank, that the return fuel would push itself (up) into the swirl pot. But now that I think about it, the fuel would take the path of least resistance and actually just dump itself into the main tank. I need to fix this...

I was more concerned with gravity pulling fuel out of the swirl pot during main tank starvation and thus created all the lines to be elevated above the pot.

I think the most simple solution for me is to cap off the OEM return and follow the same concept as that diagram and just plumb the return fuel directly to the swirl pot.

Seeing as there havent been many replies here, perhaps this was better placed in the Racing section? Or, it just you and I that have this setup

 

haha sweet. im doing something like this for my setup (13b-re fd)

 

Great idea but this stuff needs to be under the car, not inside of it.

 

???huh??

most of these are track car setups, and no, they are not usually setup under the car.

 

>>I think the most simple solution for me is to cap off the OEM return and follow the same concept as that diagram and just plumb the return fuel directly to the swirl pot.

I dont think the oem return gets capped, its just the return from the swirl tank goes to the oem return (typically the top fitting on the swirl tank is used as the return to the main tank, so it only returns fuel when to the main tank when its full), and the rails return goes to the swirl tank.

we need to do some a,b,c, 1, 2,3 diagrams here LOL

 

TheCrazyAZN: That is a beautiful set up!

I'm in the process of trying to figure out how I'm going to route everything on my track car. I have an ATL 22gal fuel cell and their surge tank that goes with it... now to get everything plumbed. Big thanks Damian for posting this.

 

Damian, Ive met you a couple of times in Joliet. You took my son for the ride of his life for 8 or ten laps there. I have nothing but respect for your driving skills, innovation, etc with the FD, but even on a track car, thats like having a gas can, in the car. A bad hit to the rear, broken fuel lines with a pump feeding them inside the car would be a bad thing. I want to see you here for a long time.

 

FWIW, I've seen surge tanks in the passenger compartment and under the car outside the passenger compartment. As always, check the rule book for your class or series.

On one ex-Motorola Cup FD, the surge tank was located under the car behind the bins. On other cars, I've seen it inside. In the in car situation, I can't remember if there was an enclosure to separate/seal off the driver compartment from that fuel system in the rear...

 

Nice setup.

I would think than an in-car fire-suppression system (probably min. of 5-lbs.) might be necessary with a non-firewalled surge tank . . .

The RedLine Time attack rules requires a "firewall" for a surge-tank (or fuel cell) located above the original floor-line. The “firewall’ can be an additional metal box that surrounds fuel cell, fuel lines, fuel fillers, etc, or it can be a single piece of metal that bolts in place, is welded in place, or is riveted in place, across the rear of the vehicle between the two rear “shock towers”, completely sealing off the items containing
fuel, from the driver cockpit.

http://www.redlinetimeattack.com/Upl...ttackRules.pdf

Rule: 1.6.4.6

Damien- I think your cover that "bolts in place" would be fine . . .

TheCrazyAZN: it looks like it might take alot of work to get a partition on you setup . . .

:-) neil

 

I think safety is always a great idea that can rarely be overdone(relatively speaking of course... extra weight is extra weight)

My car has what I consider to be a pretty good firewall, sorry I don't have better pictures of it:


Here is another way to skin the cat. This is Charlie from Mazcare's FD track car he is building. He also has a 3 nozzle fire supression system that covers the fuel cell, the driver, and the engine(I'm a huge fan of his car):
http://www.v8rx7forum.com/attachment...7&d=1250990707

Without the top enclosure piece:
http://www.v8rx7forum.com/attachment...9&d=1248999980

EDIT: I deleted the img tags because the pictures are showing super huge!

 

^ Gotta be a member of the v8rx7forum to view the pictures

 

Here you go.

All I can say is, WOW!

:-) neil

 

I'm not too familiar with surge tanks, but is an external pump needed with dual Walboro in-tank pumps?

 

Thanks

 

Could I get an answer please? Is the external pump after the surge tank necessary to pull fuel from it?

 

the entire idea of the surge/swirl tank is to pull fuel from it, and not the main tank....so i am not sure what you are asking?

i think maybe you are missing how it works, the pump in the fuel tank becomes just a feed pump, it does not make pressure to the rails once a surge/swirl tank is in place, since the swirl pot has a return back to the main tank... so the second pump (external pump in the setups shown here) is the pump that actually provides the fuel pressure to the rails, with fuel from the swirl tank.

 

Thanks Damian, that's exactly what I was asking!

Have you seen Hyperion's surge tank cover? Was wondering why you went this route over this:

https://www.rx7club.com/group-buy-center-69/gb-interest-fd-surge-cover-anti-starvation-tank-mini-fuel-cell-694665/

 

Yes, my buddy Andy (gooRoo on teh forum) ran that cover in his FD. It is a good step, but in a race car like mine, you really need a swirl pot setup to be able to run the main tank as low as you can and not starve under the high Gs that the car can pull.

For a moderatly fast street/track car, Hyperion's cover can really help and is a good solution if you are not in a position or do not have the need for doing a full swirl tank setup .

 

>>Damian, Ive met you a couple of times in Joliet. You took my son for the ride of his life for 8 or ten laps there. I have nothing but respect for your driving skills, innovation, etc with the FD,

thanks :-)

>>but even on a track car, thats like having a gas can, in the car. A bad hit to the rear, broken fuel lines with a pump feeding them inside the car would be a bad thing.

I do appreciate your concern, as anytime you are dealing with fuel it needs to be taken seriously. the impression I get is that of a difference of exposure, before I got into the race world, I would have said the same thing you did, but after years of being exposed to certain things, like gas lines and surge tanks inside the car, then it is becomes more 'normal'. Keep in mind that that tank and lines are covered with a metal lid (see pictures in my first post) and also there typicaly is a fire supression line routed to that area as well (I will be adding that to my current fire supression system soon), also most rules dictate that there has to be some sort of metal separation, cover, or firewall, between the fuel components and the rest of the cabin if they are inside the cabin, as well as 'armored' fuel lines if they are inside the cabin (ss-braided or solid metal pipe, et)

If you look in the race car thread on fuel setups (like this page of this thread for BigAls race car: https://www.rx7club.com/showthread.p...65#post9493065) you will see that it is VERY common to have a surge tank, external pumps, lines, all inside the cabin of the car in the rear, however you will also see that they are usualy behind a over or firewall created to separate them from the rest of the cabin (just like I have in that pic at the top of this thread).

>>A bad hit to the rear, broken fuel lines with a pump feeding them inside the car would be a bad thing.

I would agree that a broken fuel line would be a bad thing, but if a rear hit gets to the surge tank and lines, then that is the least of your worries, a hit that bad would mean the main tank has been compromised, since the main tank sits farther out in the rear. It would take a very odd impact to get to the surge tank and lines that are much farther in.

In either case, I am a big supporter of safety and always look to improve the safety of the car with the resources I have available.

 

looks cool , i made something even simpler are more compact but involved some a Nissan part !

Used the top from a 180sx tank ,which holds the fuel pump assembly and fitted a r33 Gtr pump to it

This is a old pic but you get the idea , will get a complete pic of the other parts in the boot

 

^^ nice work!!