Fuel system upgrade time - quick questions!

[DRAGON]

I dont think the initial poster wants advice on experimental F1 fuel systems, I dont think he has that budget.
Im not against different ways of doing things, but this guy is modifying his own car, so the best advice to give him is the tried a tested advice.
Also Jon, I dont think that your system would actually work as you say the last rail as a return line? Was your initial post just a mistake and you got the FPR in the wrong place?

[AtomicRex]

Hiya Ross
 
Ok I admit I got confused between the 2 systems, and I wrongly suggested you should put the FPR before the rail. When you mentioned this, I realised my error!! I\'m sorry, we all mistakes, I\'m sure even you\'ve made the odd mistake once in your life?
 
So to clarify....
 
There are 2 systems you could put in your car:
 
The first has the pump feeding the rails, and the FPR regulating the pressure after the rails.
 
The second, which it isn\'t an experimental system, and its how we are going to be running the fuel system in our own cars this year.
 
Basically the line runs from the fuel pump through to the rail and then capped at the end. The FPR sits on the bulkhead and vents anything above base pressure back to the fuel tank. It is a very simple system, and prevents hot fuel from going back to the tank.
 
As the fuel increases in temperature it also increases the pressure, this will effect the mapping.
 
So it wasn\'t, or isn\'t an experimental design. I think it is quite a sensible design. You have to agree it has its merits?
 
If it wasn\'t for the loss of pressure in the lines it would make even better sense to have the FPR next to the tank as that would minimise the amount of hose you would need to run. So a compromise needs to be met.

[DRAGON]

Respect for admitting your mistake.
I have heard about this fuel system before, my biggest reservation being that it has not been used before in any volume, why havent more tuners, or manufacturers employed this system?
Yes you could use the FPR near the tank, which, I would only do this type of sytem if this was a possibility, as otherwise I dont see the tangeble benefits?

[Mazdarotaryparts]

Hi All

Below are a couple of links that should help clear up any confusion,

One is a diagram of how to plumb and the second is the explanation of how a regulator operates,

http://www.fuelsystem.co.uk/PBV-INST.pdf

http://www.shyauto.com/Downloads/RX0707.pdf

Hope this helps,

[shaunwil]

This thread has turned into some interesting reading

Out of interest could you put a small radiator in the return line to take the heat out of the returning fuel ?

Shaun

[Mazdarotaryparts]

This thread has turned into some interesting reading

Out of interest could you put a small radiator in the return line to take the heat out of the returning fuel ?

Shaun

You would do this not on the return but on the feed as it would possibly result in a cooler charge leading to more horse power,

Particular in hot country\'s serious Drag racers often use an open top can with the fuel line inside shaped as a coil on the outer wall inside of the can then they pack the inside with dry ice to cool the fuel as it passes by,

As a side bar, F1 non refueling could be interesting and instead of decreasing costs, why, because last time they outlawed refuling teams came up with elaborate ways of cooling the fuel so it would contract and let them put more fuel into the tank than it would normaly take,

Lot of em still ran out though,

[AtomicRex]

Respect for admitting your mistake.

Thanks:Thumbs-up
 
If nothing else, by me making a mistake everyone has questioned why it is done the way it is...good way to learn...even if it is a tad embarrassing :Hammer
 

I have heard about this fuel system before, my biggest reservation being that it has not been used before in any volume, why haven\'t more tuners, or manufacturers employed this system?
Yes you could use the FPR near the tank, which, I would only do this type of system if this was a possibility, as otherwise I don\'t see the tangible benefits?

I think one reason is that the rail would always be live, hence my earlier suggestion of a schrader valve at the end to release the pressure.  That might put the manufactures off, but as for the tuners...cant think why more haven\'t tried it.  Hopefully it will prove a success.
 
Running standard 200 hose, as it isn\'t smooth bore, I think you would run the risk of frictional losses within the pipe....I might ask Goodridge if they have any figures on this.  The 811 hose is a smooth bore, so should allow the FPR to be mounted by the tank, and as we can run the hose within the car, the run should be shorter and cheaper than running a second line for the return.
 
Our new 110L tanks are mounted in the bins, which keeps the hose run even shorter
 
The tanks are rather nice....Dry breaks, twin fillers, twin collectors, fully baffled and foam filled.  Don\'t weigh too much either.  Cheap too if anyone is interested in a conversion!!
 
I did toy with the idea of cooling the fuel, if you could employ something similar to the cooling of a fridge and wind the pipes around the fuel line?  Sticking another radiator in line isn\'t very easy as it requires an air supply, and you don\'t want to create extra runs for yourself.

[shaunwil]

Surely you could place it in a vented area around the rear axle and have the air vented out of the back of the car ??

Shaun

[AtomicRex]

I guess you could...this is similar to where we ran the rad for the diff cooler last year.
 
As we are running the tanks inside, then it would mean taking the fuel backwards to bring it forwards again.  Plus the car has a diffuser at the rear and a flat floor...so not easy to tap into an air flow

[JayDee]

Ross give kerim a ring about this way of doing the fuel system, its a neat solution!! saves alot of circulating from rear to front back to rear!

, why havent more tuners, or manufacturers employed this system?
cause most dont think about it!

[AtomicRex]

1 thing not mentioned...you need to run a vac pipe back to the FRP....but the difference in cost of this over the braided fuel pipe...
 
I did do some research today...in between wiring the garage....so cold in the garage!
 
 
 
Here is a bit:
Returnless Fuel Systems
 
Have been adopted by several motor manufacturers and differ from the conventional by having a delivery pipe only to the fuel rail with no return flow back to the tank.
The returnless systems, both the mechanical and the electronic versions, were necessitated by emissions laws. The absence of heated petrol returning to the fuel tank reduces the amount of evaporative emissions, while the fuel lines are kept short, thus reducing build costs.
 
Mechanical Returnless Fuel Systems
 
The ‘returnless’ system differs from the norm by having the pressure regulator inside the fuel tank. When the fuel pump is activated, fuel flows into the system until the required pressure is obtained; at this point ‘excess’ fuel is bled past the pressure regulator and back into the tank.
The ‘flow and return’ system has a vacuum supply to the pressure regulator: this enables the fuel pressure to be increased whenever the manifold vacuum drops, providing fuel enrichment under acceleration.
The ‘returnless’ system has no mechanical compensation affecting the fuel pressure, which remains at a higher than usual 44 to 50 psi. By increasing the delivery pressure, the ECM (Electronic Control Module) can alter the injection pulse width to give the precise delivery, regardless of the engine load and without fuel pressure compensation.
 
Electronic Returnless Fuel Systems
 
This version has all the required components fitted within the one unit of the submersible fuel pump. It contains a small particle filter (in addition to the strainer), pump, electronic pressure regulator, fuel level sensor and a sound isolation system. The electronic pressure regulator allows the pressure to be increased under acceleration conditions, and the pump’s output can be adjusted to suit the engine\'s fuel demand. This prolongs the pump’s life as it is no longer providing a larger than required output delivery.
The Electronic Control Module (ECM) supplies the required pressure information, while the fuel pump’s output signal is supplied in the form of a digital squarewave. Altering the squarewave’s duty cycle affects the pump’s delivery output.
To compensate for the changing viscosity of the fuel with changing fuel temperature, a fuel rail temperature sensor is installed. A pulsation damper may also be fitted ahead of or inside the fuel rail.

[JayDee]

its the best way to do the fuel system to me, the aeromotive regs have built in dampers, will make enginebay alot neater as well

[Oliver]

The second, which it isn\'t an experimental system, and its how we are going to be running the fuel system in our own cars this year.
 
Basically the line runs from the fuel pump through to the rail and then capped at the end. The FPR sits on the bulkhead and vents anything above base pressure back to the fuel tank. It is a very simple system, and prevents hot fuel from going back to the tank.
 
As the fuel increases in temperature it also increases the pressure, this will effect the mapping.
 
So it wasn\'t, or isn\'t an experimental design. I think it is quite a sensible design. You have to agree it has its merits?
 
If it wasn\'t for the loss of pressure in the lines it would make even better sense to have the FPR next to the tank as that would minimise the amount of hose you would need to run. So a compromise needs to be met.

Since the fuel rail end is now capped. Do you have any concerns regarding debris that gets past the fuel filter, there is no circulation of fuel back to the tank. What I\'m thinking is, the capped end of the fuel rail could become a place to trap debris and in time clog the injectors. Expecially the injector on the furthest end of the rail. Do you feel this could be a potential problem with this system or debris shouldn\'t be any diffrent then the returned system I use now?

This is a good read. I like the idea of cooler fuel, cleaner engine bay, less material to move fuel, less weight and cost for my budget racecar.

[AtomicRex]

I guess you run that risk regardless.  If the item is going to go past the fuel filter, then it will run the risk of going into the injector regardless of the circulation or not.
 
To me it is down to the type of filters you run in your system.  You should always be running a basic filter within the tank to prevent the pick pieces being picked up 90microns, but then have a good filter before the pump We use a 25 micron filter for that.