show me your fuel systems and fuel specs :)

[Timmyc]

The last major thing that im needing to do is my fuel system and was wondering how everyone has done theirs? where they have mounted everything? and what stuff their using etc?
 
I was going to try keep my fuel setup to BDC spec which i believe means i cant have any swirl pots, pumps, tanks etc in the drivers compartment without a firewall between myself and the fuel system? so i guess i dont have any option but to mount everything under the car?

[m1tch]

Here is my spec:

Braided lines
Aeroquip fittings
Parallel setup (as per fc3s pro) - Y piece fitted along the bulkhead
Aeromotive FPR
KG parts billet rails
550cc primaries
1680cc secondaries
Secondary fuel diffusers removed to fit injectors spacers
Tomei 280lph pump





Stock pump left, Walbro 255 middle, Tomei 280 right

[Timmyc]

cool man that helps did you just use stainless braided pipe or teflon stainless braided?

[TiddlesRX7]

Me being the complete noob when it comes to fuel systems wants to know what pressure you set your FPR\'s to?

Ade

[Prof]

To pass the MOT you should set the FPR to the same spec as the original FPR/PUMP figures - which is why Mitch\'s passed
 
Keeping the stock FPR with after market pump means rail pressure goes up and consequently it runs rich all the time.  You don\'t need rising rate either, as the FPR will maintain the 3 BAR pressure difference for the fuel injectors regardless of boost / vac conditions, so you can do all your mapping based on a fixed fuel pressure
 
I went for a serial fuel system - good enough for 400 bhp with stock rails, just pick secondaries to suit
 
Pic of my layout :
 
http://www.mazdarotaryclub.com/forums/attachment.php?attachmentid=46485&d=1267998502
 
The FPR on the bulkhead is an HKS part, with an AN6 male to female with 1/8 npt Tee for a standard fuel gauge.   The secondary rail is a modified S4 rail, where the end has been cut off and an AN6 weld on fitting attached.  The primary rail has 2 AN6 adaptors fitted.

[TiddlesRX7]

So 3 bar then. Cheers Prof.

[m1tch]

Do you have an AFR gauge in the car? Mine idles at 14.7:1

[Timmyc]

great info cheers guys, so mitch your saying its perfect!  :p

[m1tch]

great info cheers guys, so mitch your saying its perfect!  :p

Its shiny

[Prof]

So 3 bar then. Cheers Prof.

with the yellow jumper bridged (near drivers shock tower), so the fuel pump runs at full voltage, you are looking for about 40 psi on the fuel gauge - engine NOT running.  Take the jumper out, and at idle, after it\'s run for about 1 min, the pressure will be lower - about 30 ish

[m1tch]

Mine is dead on 30psi when idling

[GeenIdee]

-walbro 255lph fuel pump
-braided fuel lines from tank to motor
-S4 turbo fuel rails
-fuel rails paralel
-stock primary, 800cc sard secundair
-aeromotive fpr
 
 
What i would like to know is what kind of fuel pump en what kind of filters is recomended for use with a swirl pot.

[Timmyc]

this is useful info guys, wondering about swirl pots also, can they be mounted anywhere? does the orientation of the pot determine its efficiency?

[HaywardRotary]

Alot of people won\'t agree with this but what you want can be done alot more simply.
1. use stock fuel pump
2. use existing primary rail and injectors
3. use existing secondary rail with minor mods to take 1680cc injectors and remove original regulator and use Aeromotive one.(Requires some welding)
4. some fuel pipe will be needed but not alot

This setup will make over 400 hp no trouble and save any costly messing around with fueling in the tank. Change the fuel filter of course.
We have done this mod quite a few times, an example is full bridgeport with T88 turbo running 1 bar boost.

Hope this helps
Regards
Carl

[Prof]

Carl,
 
Do you keep the pulsation damper then ?
 
I eliminated mine, but have a better flowing fuel connection (swept AN fittings) rather than the banjo setup that normally feed primary rail.  I suspect with 1680\'s in the secondary rail, you need to have some form of balancing (parallel fuel system), or a pulsation damper.
 
 
Other than that, my setup sounds similar, although I did upgrade the fuel pump to a walbro just because the stock pumps are getting old now, and only needed 800cc injectors to get what I wanted.  With a slight increase in fuel pressure the 550 primaries / 800 secondaries will fuel for close on 400 bhp.