Fuel What is the limit of the stock fuel rails?

Discussion in 'Fox 5.0 Mustang Tech' started by stangboy, Feb 22, 2013.

  1. Hey guys I'm getting to the nickel and dime part of my parts buying for my project. I was about to buy a set of BBK fuel rails but i was told that they are notorious for leaking. My tuner strongly discouraged getting them. The problem is that I don't have enough budget to get the Aeromotive fuel rail kit...that I REALLY want. Are there any other decent quality fuel rail kits out there? What are the limits of the stock fuel rails? If you have any questions about what I'm building check out my build thread "My first notch build" in the Talk section. Thanks in advance guys.
  2. I'm running stock fuel rails, lines, etc., with only an upgraded fuel pump, with my 369 (363 .030 over), AFR 185 comp, Holley systemax, 90mm MA, 80mm TB, 1 7/8" Kooks, 3" full exhaust, and relatively small cam making 425 rwhp.
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  3. On my last set up I was making 450rwhp on 9psi with a stock bottom end, trick flow top end, custom cam, 255 pump, and 42# injectors (along with other supporting mods). Building a 331 now and going for more boost so I'd also like to see the answer (if there is one) for this.
  4. Behind Bars Race Cars makes nice fuel rails. I would say it's time for new fuel rails once you exceed the flow capabilities of 42lb injectors. My vortech combo was making over 500 to the wheels and the 42s were done at that point.

    I'm not sure if there is anything to be gained by just upgrading the fuel rails. Seems like it's necessary to upgrade the feed and return lines as well as they will then become the bottleneck in the system.
  5. I start to recommend guys consider rails when using a large injector in the 500hp range. The stock rail just doesn't keep enough volume of fuel at the injector IMO.

    I make my kits using the new style BBRC rails as well, very nice pieces that allow feeding straight through and on a fox clear the dist 99% of the time with no additional spacers.
  6. If you are not over 500rwhp don't waste money on fuel rails.

    Btw, connecting fuel rails also costs more money in fittings and hose.
  7. IMO you should replace those rails when/if you go aftermarket block and exceed the 500rwhp mark. 10.30's on stock fuel rails here with my buddies car.
  8. Well, it seems like I should be ok with the stock rails for now. I'll probably make more than 500 at the wheels with nitrous tho. I'll be using a wet kit tho. Will that be a problem with stock rails?
  9. What do you have going on with the rest of the fuel system? I would imagine that the rails with a wet kit to add fuel would be ok.
  10. I have an Aeromotive 340lph pump in the tank so I'm sure it can handle the fuel demand.
  11. Are you still running the stock fuel lines or have they been upgraded as well?
  12. Stock fuel lines. Plan to upgrade the whole fuel system later on when my budget allows. I may start piecing it together instead tho. I'll have to see how things look once the motor is in the car and I can see if the current fuel system can handle the demands of the motor.
  13. Fuel pump sounds fine, but i would really like to see -8 feed and -6 return on that setup. I'm hoping you'll be testing this on the dyno so you will know where you stand with the fuel system. It would be hard to know where you stand with the fuel system tuning on the street or track, going lean once can be bad bad news.
  14. Oh yes, this will be tested and tuned on the dyno. I have seen what a lean condition can do to an engine.