I've been reading through the archives here with regards to how best operate the Oil Metering Pump on the 20B, or solutions to it. I'm a little confused on a couple of things and hope that people can help clarify for me.

1) Why is it that people switch to the 13B front cover/water pump? If there are concerns over the potential output of the 13B water pump why wouldn't people use the 20B pump? I am generally confused why ANY of the front cover or accessories need to be swapped out. My motorset came complete with everything (AC, PS, etc) and I would like to leave it that way if possible. I would also imagine that the 20B waterpump and alternator are both higher output units than on the 13B.

2) Why is there discussion over using an S4 NA front cover with mechanical oil metering pump? Is this due to the inability of older ECU's to control the 20B's electrical OMP? I have read and seen numerous posts and diagrams showing the new E11v2 is capable of handling the 20B's OMP and would like to go that route unless anyone can suggest reasons otherwise.

Thanks in advance, I searched as much as was reasonable to determine the answers to the above questions!

 

Well,

The 13BRE and 20B both share alot of parts from S5 T2, unfortunately. As far as i Know, the 20B uses an FC waterpump, and a super goofy twin thermostat setup in the water pump housing. Most change this out for simplicity. Im using the FD waterpump, cuz it matches with the FD pullies and CAS im using on the FD front cover. Most people dont want to bother with using the stock MOP system, so they switch to S4 NA front cover to use the mechanical oil metering system. I chose to use the FD front cover to get away from using the FC crank angle sensor that the FC and 20b both use. I am premixing and have absolutely no desire to have anything to do with stock MOP. I also removed the mop shaft and gear as well as blocked off the oil feed for it.

 

The Wolf 3D +plus version ecu will run the OMP's.

 

Does the 20B MOP have the same oil flow capacity as the FD pump? A few people have said it does, but I'm not sure what their basis is. I have also been told that the 2 rotor pump operates close to 100% output at low boost. If the above two statements are correct then using the stock 20b pump with a high output motor does not seem like a good idea.