Uprated fuel system?

Discussion in 'Mechanical - Engine, Gearbox, Exhaust etc' started by rTEM, Jan 23, 2017.

  1. What fuel setup is recommended for a 300+/300+ r26, running 630cc and 250 turbo? Having a forged engine build and don't want to risk running lean and braking ring or piston again. Was a discussion on Facebook not so long ago about cilinder one issues on numerous meganes due to piss poor fuel setup on meganes.


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  2. Bump

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  3. ianplymouth

    ianplymouth RSM Club Member

    I have a 250 engine in my 225 with standard fuel system and Paul at RS says its fine and recons i will get around 320+Hp with 630 injectors, decat and the other stuff, will know more on Monday after he has worked his magic on it :sunglasses:
  4. Thanks for replay, but there is the risk of running lean with standard fuel setup, it is capable of delivering the numbers u mention safely, without the car moving, fuel moving in the tank. There was a good post on facebook about this problem. I will defo get a better fuel setup before the final mapping. Have spent 3k on parts only, not going to risk it mate.


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  5. ianplymouth

    ianplymouth RSM Club Member

    I am sure Paul knows what is safe, if i do a track day i never let the fuel gauge go below 1/3 of a tank just in case.
  6. Sure he does, will ring rstunning for advice. When my engine went i about 1/4 to 1/3 of fuel and was driving trough some roundabouts, spirited. Just the post on facebook made me think

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  7. The 250 fuel rail is a better design than the 225, where the fuel feed is in between cylinder 2 + 3. On the the 225 the fuel feed was at the cylinder 4 end of the fuel rail hence why cylinder 1 is typically the cylinder that will run lean.

    Additionally, the 250 has a better fuel pump providing 5.5bar at the rail over the 3bar that the 225 pump gives.

    The 250 fuel rail has a secondary fpr at the rail which allows the rail pressure to vary from 3bar to 5.5bar.

    For heavy track use (or if you are going for big power), the best option would be an external fuel pump with swirl pot. But to do this mean fitting an aftermarket fuel rail with a return fuel line.
  8. Thanks for the info mate. Power wise is what i can get out from 630cc and 250 turbo.

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  9. If you are on a 225 engine and fuel system I would say that 300/300 would be the limit. You can get more torque but on standard internals most mappers would limit it to 300lb/ft. To get there you would probably also need a bigger FMIC, and probably a freer-flowing exhaust.

    Edit: Just read your first post about the forged internals! I think you will struggle to get more than 300hp without other work on the head/inlet/cams/hybrid turbo (select most appropriate). With forger internals you can probably get an extra lump of torque though.
  10. Whatever it makes, i will be happy. I was happy with 282/300 before the bang. Now that it is being forged 250 turbo is a logical upgrade, but i want it safe

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  11. 250 turbo with the usual upgrades I.e. exhaust, induction fmic should see around 320 I would have thought.
    I forget who, it is but on a mk2 with 250turbo, and normal mods got around 310/315bhp with torque limited to around 310lbs

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  12. Mick Calvin on facebook, before he smashed it, was running 311bhp.

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  13. That's a good number! It does depend on the car a bit, but 311hp is impressive.

    I run a 250 engine and turbo in my 225, but I eventually want to run a better in tank fuel pump and up the line pressure to 5.5bar. My current fuel pump is a bit wank and I think is struggling as it is!
  14. Even forged stuff melting when fuel system fails? Who or where is the best place to ask? Pro-line motorsport was mentioned on facebook

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  15. matt e

    matt e South East RSM Area Rep

  16. I remember reading about this. He has that meg engined clio with upgraded fuel setup

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  17. ianplymouth

    ianplymouth RSM Club Member

    Had a look earlier today at mine, the 225 fuel rail is a lot smaller in diameter than the 250 one, the 250 one is square and made of stainless steel and the feed is in the middle as ewant said, might be worth looking at one.
  18. matt e

    matt e South East RSM Area Rep

    is the spacing the same for the injectors as the 225/230?
  19. Thanks mate

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  20. ianplymouth

    ianplymouth RSM Club Member

    I am sure it is, as i am sure the cylinder head would swap and the intakes on the head would be the same, i'll check tomorrow if you want me too.

    Just checked and the inlet manifold gaskets have the same part number, but the 250 intake plenum is larger in diameter and slightly longer though, but fits.
  21. ianplymouth

    ianplymouth RSM Club Member

    rTEM likes this.
  22. Hi boys, so it is possible to fit 250 fuel system, pump rail secondary fpr to r26? Or is it easeier aftermarket setup?I am just learning how this all works.


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  23. matt e

    matt e South East RSM Area Rep

    what power are you after?
  24. Whatever 250 turbo and 630cc make, power is not my priority mate. Just want it safe to have fun. 250 fuel setup or aftermarket, what is easier to be done?

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  25. I know that the 250 intank fuel pump and regulator doesn't fit in the 225 tank. The fuel tanks changed shape between the cars.

    To take full advantage of the 250 fuel rail and secondary fpr, would have to upgrade the 225 fuel pump to provide 5.5bar to the rail. That means monkeying about with the 225 intank pump and fpr.

    Otherwise you go external fuel pump, custom fuel rail, swirl pot and return line.

    There are alternative fuel pumps that fit in the 225 intank body, but I haven't been able to find a fpr to put in the intank body that is a direct swap and gives 5.5bar.
  26. Thanks again mate. Any idea how much am i looking at, roughly, for external route?

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  27. ianplymouth

    ianplymouth RSM Club Member

    From what i can work out and have been told, the 250 fuel pump will fit but needs a bit of modifying to get it in, that then gives you 5.5bar at the fpr valve, only 3.5 bar is used and when on boost of say 1 bar the fuel pressure in the rail goes up to 4.5 bar because of the 1 bar air pressure it drops it back to 3.5 bar.
    You can still use the 225/r26 pump that will still give you 3.5 bar at the rail, but if you fit the 250 fuel rail you need to disable the fpr valve, i blanked off the pipe on the manifold (i have the 250 manifold fitted) and removed the small "O" ring from the fpr valve so it has full flow of fuel to the rail.
    This is why they recommend 630 injectors, so they can open them for longer to give more fuel at a lower pressure.

    I bought a complete 250 intake manifold, it came with a set of injector and the fuel rail for £50 came off a 250 TCE ! ! ! same part number though.
  28. I hadn't spent much time looking to be honest, but a quick google search shows up a swirl pot kit from ktec racing at a not too bad price.


    They also do a custom fuel rail but it's only advertised under the Clio?


    Torques do a swirl pot and fuel pump kit on their eBay store:


    Install and fuel lines would be extra, perhaps also an additional FPR would be needed.
  29. I must go trough your build tread again and pay more attention this time. Thank u

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  30. Thanks for the link mate

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  31. Who runs an external swirl pot on their mk2 then? Recommended for any meg 2 that does a lot of track days or just in general
  32. I can't seem to source a 250 fuel rail!

    Plenty for the diesels and lesser engines but I assume the 250 is different?
  33. ianplymouth

    ianplymouth RSM Club Member

    Yes they are like hens teeth, the 2.0 Tce one is the same by the way
  34. Bit the bullet and ordered a new part from Renault!

    Not the cheapest, but cheaper than the engine blowing due to starvation!
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  35. So I've got the rail and regulator on order, do I need to update the fuel pump to work with this new set up, or will I be okay? From what I can see, I may need to do away with fpr as the 225 pump won't supply enough pressure but not sure if a new pump that'll drop in would work best? I'm not exactly sure on what's involved changing the pump tbh.

    Not sure if the fuel line will need extending to reach the central fed rail too?
  36. ianplymouth

    ianplymouth RSM Club Member

    Best to fit anther pump, i fitted a dw65c and a 5bar relief valve in the tank, easy job to do once the pump unit is out, make sure you have half a tank of fuel or less.
    There is a proper tool for removing the retaining ring but its not 100% necessary.

    Then you can fully utilise the fuel rail.

    The fuel pipe will reach, just take it easy and reroute it, don't worry about the original clips, a couple of tie wraps and plastic pipe work well
  37. This is all new to me, so please bear with me lol!

    Will that pump just slot in? I'm assuming that the relief valve goes just after the pump with a return to the tank?

    So it would be:
    New pump,
    Relief valve with return,
    Fuel rail.
  38. ianplymouth

    ianplymouth RSM Club Member

    the pump is a virtual slot in, might have to trim a small piece of plastic off of the pump, the pressure relief valve fits into the top of the pump housing, its held in with two small screws (i'm sure) the neck has to be turned down to 7.8mm i think, it is 10mm to start with, you just take the old one out and put the 5bar one in its place, no need for a return as its in the tank.

    Does your fuel rail have a relief valve fitted ????
  39. No idea tbh! As far as I know it doesn't.

    I've ordered the rail from the 250 from Renault, it's got to come from France so will take a week before it gets here.

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