Uprated fuel system?

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

 

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.

 

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.

 

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.

 

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

Sent from my HTC Desire EYE using Tapatalk

 

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!

 

is @Stephenvenning still going to make fuel rails?

 

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.

 

is the spacing the same for the injectors as the 225/230?

 

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.

 

This is what it looks like, part number 8200797469

http://www.ebay.fr/itm/RAMPE-INJECT...-RS-COUPE-CC-2-0-16V-0280158211-/272085999615

 

what power are you after?

 

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.

 

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.

 

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.

http://www.k-tecracing.com/show_product.asp?id=4519&appid=12

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

http://www.k-tecracing.com/show_product.asp?id=5543

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

http://www.ebay.co.uk/itm/Twin-Bosc...8-AN10-Blue-/380866283972?hash=item58ad6649c4

Install and fuel lines would be extra, perhaps also an additional FPR would be needed.

 

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

 

I can't seem to source a 250 fuel rail!

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

 

Yes they are like hens teeth, the 2.0 Tce one is the same by the way

 

Bit the bullet and ordered a new part from Renault!

Not the cheapest, but cheaper than the engine blowing due to starvation!

 

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?

 

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

 

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,
Fpr,
Fuel rail.

 

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 ????

 

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.