Megane RS250 engine into R26 - using mk3 fuel pump

[Ewan]

I am swapping the engine in my R26 with a RS250 unit retaining the R26 ECU and loom. Should clarify at this point that 'I' means 'I am paying Rentec in Edinburgh'

Ok, so we are keeping the R26 ECU and loom and swapping in the RS250 engine with turbo and the mk3 inlet manifold, fuel rail and injectors.

I know that we should be able to run the RS250 engine with the existing mk2 fuel pump, although it won't offer the rising rate fuel pressure. The question is can we fit the mk3 fuel pump to my car and take advantage of the rising rate rail with the mk2 ECU and loom without a massive headache?

 

[Ewan]

Finally sourced a 225 fuel pump. I will take some pictures of the pump and fpr for reference and check to see how the 250 fpr fits.
Any news on the Lexus sender and fpr?

 

[Ewan]

Been a while since I done anything with this but finally managed to get the 225 pump out the body.
Pictures of the pump below...

 

[Ewan]

Anyone which Walbro fuel pump is a direct swap? I am thinking it is 255lph pump...

 

[Ewan]

Never mind..bit of googling and it should be the Walbro ITP116

 

[tutuur]

Found out a 197 has a completely different fpr compared to the 225 and 250. My luck is i had already bought a 1.2 sender which does seem to work!

The dw65c is a direct fit aswell

 

[Ewan]

That was lucky, take it the 1.2 runs at 3.5bar as well?

There are a couple of bad reviews with the dw65c pump, what's your experience with them?

 

[tutuur]

I have no experience with them tbh.

Yes the 1.2 has a 3,5bar regulator, there's no marking on the 197 so god knows what pressure it's running but i'm assuming 3,5bar aswell

 

[tutuur]

Just looked into the itp116 but afaik it's longer then the original pump.....

I think you need the dw65c

 

[Ewan]

Just looked into the itp116 but afaik it's longer then the original pump.....

I think you need the dw65c

Picked up a dw65c during the week and I can confirm it is a direct swap for the standard Bosch pump. If you are buying one, then the universal pump without clips is the one to get. Need to retain the original pumps sock as the generic one they provide doesn't fit.

Hopefully get this fitted middle of next month. As this pump draws a fair bit of current, something like 10A+ at 3.5bar, it will need a direct line from the battery.

 

[Ewan]

Doing a bit of digging on the web and came across this external fuel pump and surge tank suitable for returnless systems. Much want, however also much expense

FST-R, Fuel Surge Tank with Integrated FPR

 

[DaveL485]

Doing a bit of digging on the web and came across this external fuel pump and surge tank suitable for returnless systems. Much want, however also much expense

FST-R, Fuel Surge Tank with Integrated FPR

You could replicate that with a normal swirl pot, an external pump, and some AN6 fittings. Its just a repositioning of the regulator in the system loop thats all. Normally you go around a full loop

Swirl>Pump>Rail>Reg>Swirl

but with a returnless you go

Swirl>T-Piece (T1 and T2 being the outlets)
T1>Reg>Swirl
T2>Rail

The downside being if the reg is at the back you cant really fit a vacuum reference to the reg for rising rate, which you need on a turbo car to equalise the differential between manifold pressure and fuel pressure unless you run a high enough static fuel pressure for that not to matter, so a minimum of 3bar plus your max boost pressure.

 

[Ewan]

For my application I wouldn't need the vacuum reference, a static 3.5bar would do the job. If you use the RS250 fuel rail, you have an additional reg on the rail that you can attach a vacuum reference.

The biggest advantage imo with this setup is that it sinks the pump inside the surge tank which should help to cool it, and keep the noise down. Also you don't have the problem of warm fuel returning to the surge tank in the return less system.

Didn't think it was too bad a price for the unit, it's just a lot of money to throw at a car!

 

[tutuur]

You'd need an intank unit of more than 3,5bar! 5,5 to be exact, just like the standard megane 250 item

 

[DaveL485]

a static 3.5bar would do the job

Need higher than that bud, a static pressure i'd want a minimum of 2.5 bar above what my max boost would be with with some safety margin too. The 5.5bar tutuur mentions would be what i'd aim for.

 

[rTEM]

Any updates on this? @Ewan

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[Ewan]

Yeah, the dw65c was a straight swap into the 225 fuel body I had picked. As it pulls way more current than the standard pump, got a new feed from the battery running off a relay on the existing wiring.

The new pump is much, much quieter than my old one which makes me realise how shagged the old one must've been. No problems since but now I don't run less than half a tank on track for safety.

On another note, the fuel body that came out the tank of my R26 was completely different to the 225 one bought. The fpr is much smaller and the whole body looks cheaper. Will take some pics and post here next time I have some time free in he garage.

 

[Ewan]

Got some pictures of the R26 fuel body with its different sized fpr. Renault must've changed the unit from the phase 1 Meg, and I am sure that someone told me this before. From memory it was Christine Bock's husband who had the forged phase 1 inferno 225. He also had problems getting a decent fuel system. Must get in touch with him and ask him what he did in the end.

Anyways, here are some pictures of the R26 sender and fpr







Don't know if anyone recognises the size of the fpr, but it's definitely smaller than the phase 1 Meg one and the rs250 one.

 

[tutuur]

That's what i've told you al along. You can fit the 250 one after putting it in a lathe to reduce the diameter of the nose

 

[rTEM]

Does the dw65c have its own pressure regulator? Also walbro makes a drop in pump and a guy on Facebook has it installed @Ewan and thank u for the pictures

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[Ewan]

Does the dw65c have its own pressure regulator? Also walbro makes a drop in pump and a guy on Facebook has it installed @Ewan and thank u for the pictures

Sent from my SM-G920F using Tapatalk

No, the dw65c is a drop in pump but runs much quieter than the Walbro. Would recommend the dw65c over the walbro, although it's a few quid more expensive.