Megane R26 getting a 250 engine & turbo

The project started Friday eve after I finished work Before I get started I would like to say a big thanks to Ianplymouth & ewant81 for all the advice and information they gave me to do this conversion.

I started by removing the complete front end of the vehicle.
I then went underneath and drained the engine and gearbox oil and dismantled the suspension so I could remove the drive shafts, I unbolted the cat from the downpipe and removed lower gearbox mount.
I then pulled the engine out using the crane.
This process took around 3 hours to complete which wasn't as bad as I thought.

Next up was swapping the parts I needed from the 225 engine, first I swapped the thermostat outlet as it has a different angle on it meaning can use your standard hose setup.
I went with the 225 throttle body, I made up an adaptor plate using a piece of 10mm thick aluminum, I marked up the 4 holes using the 250 gasket and drilled a 48mm hole using a hole saw. I worked out a position where I could get full flow from the 225 throttle body, i drilled and tapped 3 studs onto the plate.
That's the throttle body fitted.
I removed the knock sensor from the 250 engine so I could fit the 225 sensor as it has a different connector on it.
Stud for knock sensor removed
I then swapped the oil sandwich plate over and fitted a new filter. I also swapped the coolant sensor and boost pressure sensor over but forgot to take pictures of these.

I fitted the decat to the 250 engine and cleaned the ends up and fitted new studs and gaskets after the picture was taken.


I fitted a new lightweight R26R flywheel supplied by RS tuning with new flywheel bolts torqued to spec.
R26R clutch fitted. I swapped to over the driveshaft mount from the 225 engine and swapped the coils and 630cc injectors over, i removed the fpr and got rid of the bottom o ring and the little filter and blocked of the hose from the inlet manifold but forgot take pictures of these.
Engine refitted with a new slave cylinder in gearbox.
I prefilled the slave cylinder before fitting and used the pressure bleeder to get any air out the system, I checked the pedal before putting the front back together and it felt pretty good.
I slightly modified and re routed the vacuum hoses to the inlet manifold by heating them with a hot air gun and reshaping them gently. I rerouted the fuel line so I could connect it to the fuel rail.

The front of the car was put back together and then the suspension, the car was filled with oil and coolant.
the car was filled with oil and coolant and then started and left outside to run up to temperture and check for leaks and top up the coolant reservoir once it had gone round the system.
All in all it wasn't too bad of a job and I hope get good results once the map has been tweaked by Paul. Thanks for reading

 

I forgot to add I fitted new timing belt kit, water pump and spark plugs before fitting the engine. And the 225 upper timing belt cover was swapped onto the new engine

 

Cheers mate, it's booked in for 2nd march I will definitely post up the results once mapped

 

Thanks mate, yes It's a relatively easy conversion if you want to run more power.

I used the 225 loom and ecu, I had to change a few sensors over as the plugs are different. The vvt solenoid you are talking about is still bolted in but left unplugged as the 225 ecu doesn't have vvt on it. It's actually between cylinder 4 and timing belt as renault put no1 cylinder on the gearbox end for some reason lol

 

Thanks ewant81, I will post them up as soon as it's mapped on the 2nd ​

 

Update! So far the engine seems to be running ok but I have a fault pop up saying p0325 knock sensor circuit? There's no engine light on but there's seems to be more vibration in the cabin since i fitted the engine I don't if its the he ttv flywheel? Any help would be great cheers

 

Cheers for you Input, I put the R26 knock sensor on the 250 engine. I rectified it today I put new engine & dog bone mount on and it stopped 95% of the vibration, I think the vibration was causing the knock sensor fault to come on. I have since erased the fault and it has not returned

 

Cheers I started it on a Friday night and had it done on Sunday

 

Update!!!
Today I made the 3.5 hour trip to see Paul at RS tuning, as usual he was very friendly and helpful. He put it on the rollers and then found out it had a knock sensor fault stored on the ecu! It was a simple fix luckily, all I had done was mix up the wires for the oil level & knock sensor. Once I had wedged my arm down the front of the engine to swap the plugs over it was good to go and these were the results! It's got so much more grunt now and you get a lovely bang when you change gear as you get high up in the revs

 

Yea it's great Ian so much better in terms of power and torque and also a bit of piece of mind for the bottom end. Haha yea only 7 or so hours into total for a map tweak but well worth it.

 

12 hours driving for a map is pretty mad lol but like you say well worth it, I wouldn't take it to anyone else. Thanks Gizmo I'm very happy with the results