R26 RS250 engine conversion

Hmm, I wonder if mine would be capable of similar figures? Only difference would be I'm on 630cc injectors.

If so, I may keep the 250 turbo for this year and swap it out next winter!

 

My mates track r26 makes 333bhp/345lbft on 630’s and a 250 turbo, was told it wouldn’t go much higher than that without upgrading the fuelling and turbo.

 

The dw65c is a straight swap, my last one i had to cut a bit off, but this one went straight in.

Not sure what difference running 95 fuel will make than running 99, you could add octane booster, but would be an expensive option i would think.

Running a 250 turbo won't make it peaky, as its still twin scroll you will be fine.

Why are you thinking of taking the engine and box out ?????

Power steering is electric, there is no pump

 

Ohhh that's not good, normally it's number 1 cylinder (gearbox end) if you do pull it out and strip the engine, check the valve guides are good, if in doubt change them, done 3 engines now that needed this to be done, including my new one.

If you are not going to go big power, see if you can find a set of 250/265/275 pistons, or just change the rods.

 

Thats good then, so you have the square fuel rail then ???

Basically you are going to be doing the same as i did in my 225 project.

Use the R26 wiring loom, leave the VVt valve in and don't worry about it, swap out the throttle body, i made an adapter, i couldn't get the 250 one to work without issues.

you have to use the r26 knock sensor as the plugs are different.

Before you run the engine up, let me know and there are a couple of other bit you need to know.

 

is it shiny or black ???

 

I've got the 250 fuel rail and reg ready to go, just need to upgrade the fuel pump and do the relief valve and it should be good for the 250 rising rate fuel system to be mapped in.

330bhp+ with very little cost from here is tempting as it's a good £2k+ for the big turbo option, although it would be around 100bhp more

 

Is it wort the £2k plus for 100hp

I'm sure it is, but its not just throwing a turbo on it, its the plumbing, adapters etc etc
I had an offer of another turbo, the next one up from the one i had in my 265, supposed to be good for 500hp, tempting

 

Factor in a boost controller to help make it somewhere near close to driveable in the wet too!

The reality is, 350bhp in one of these is probably the sweet spot.

 

I was quite surprised how easy it was to drive around Oulton park in the wet with 388hp and traction control off

im sure the R26 will handle the power just as well

 

The reg on the 250 looks like the same as the one fitted to the R26, but after doing some searching the 250 reg's are not available from Renault or elsewhere, seems a bit expensive to buy a 250 tank unit just for the FPR valve, the internals are slightly different as the DW65c pump wasn't a straight fit.

The mk3 fuel set up i'm going with is the fuel rail, injectors and the FPR valve in the tank, as i can then run the raising rate fuel system.

The one in the 250 is actually 5.5bar

 

Hi Chawkie

First you need to remove the fuel pressure relief valve, then you need to remove the small "O" ring on the tip, keep it safe as you will need to put it back in at the mappers.

If you put the pipe back on the manifold and take it off of the FPR valve, then block the open end with a small screw, you need this in as it will allow air into the induction and give you a weak mixture and possibly cause issue, there is no need to block the FPR valve pipe it will do nothing at this point.

Leave it like this until you are at the mappers, then refit the small "O" ring, the pipe and the injectors your using.

 

The injector fitting needs to be left till you get to the mappers.

You are right the Mk3 injectors have a long nozzle, but fitting the 630's will work as they have done on hundreds of Mk3's before, it just fires the fuel into the intake port so it doesn't have an effect on the performance, the long 630 injectors have a longer body so they will not fit.

Don't throw the Mk3 injectors away, there great for an R26 or 225 running around 310hp and still wont be at 100%

 

I presume you have done the pump in the fuel tank and added a 5bar regulator ?????

what it does is hold the fuel pressure at 3.5bar

 

its open to atmospheric pressure, until the pipe gets connected at the mappers, you don't want 5 bar solid pressure at the injectors at idle or any rpm and boost level.
Removing the "O" ring holds the fuel pressure at 3.5bar the same as a standard fuel system.

 

@ianplymouth i think you need to just write a parts list and what to do with them and then get admin to stick it as a tread

 

I think i did all this years ago on my 225, i think its in my "225 gets a 250 engine" or something like that

 

Got a new project inbound, but not saying too much at the moment

 

Yes that’s true but it’s full of chit chat. Just a straightforward to do list

still got my r26 and still want more power and still don’t want to spend thousands on it

 

Will run fine with the o ring fitted before mapping, I checked afr's and mine was fine with the 5 bar reg fitted in tank before mapping. Just leave the vac pipe off and bunged, and a steady drive to the tuner.