MarkTe30 said:
Hi JW
Thanks for the response. I'm moving more towards getting a garage to do it due to this reason and also the potential fun and games when it comes to bleeding the fuel system again. I'm new to modern BMW's and I think this'd be a little much for me.
What I'm after is a definitive list of components required, the stuff that gets forgotten about if you could please. The cp4.2 pump from a 335d or x5 d40 and modified fuel rail are a given. What else did you need. The last thing I want to do is get someone to do it and they not have everything to finish the job in one go!
Secondly, have you had your car remapped and if so, what's it like? Is there much of a difference?
Many thanks
Mark
A lot of people modify the N57 6 cylinder rail, but I just got another N47 rail; cut off and welded the end to my original rail.
The job involves taking the intake manifold off and deleting the EGR system. You will need:
EGR delete kit of your choice (I've never gotten one so I don't know who sells them, sorry)
The 2 fuel pipes that go from the pump to the rail
Intake manifold gaskets
A bottle of coolant (as deleting the EGR cooler will open the coolant circuit, might need a little top up)
O-rings for the intake pipe from the intercooler to the throttle (not required as such, but they sometimes cause boost leaks)
When I did this, I found the mount for my fuel pump didn't fit the bigger CP4.2. I don't know if there's one that fits to both the N47 and the CP4.2 unfortunately. I just attached the mount to the engine and filled the gap between the mount and the pump with foam tape so it was still secured. A lot of people also use this opportunity to delete the troublesome swirl flaps in the the manifold, I think BWChiptune do a delete kit for this.
I had my 2008 123d at 142,000miles remapped with a local tuner originally with just a dpf delete and bigger intercooler and it went from 190bhp to 225bhp. Then got it done again after the fuel pump upgrade and it went up to 260bhp and 380lbft, but it goes into limp mode sometimes. Now I'm looking to get it re-tuned at BWChiptune soon to sort this out.
I believe doing this upgrade on a 2010+ 123d can get up to around 300bhp but the older ones don't tend to make that kind of power. Hope this helps.