New To Me 4.6is

[Henn28]

Originally Posted by OGX5M

@Henn28 Def. a smart/cost-effective play. ZF still making awesome gearboxes for OEMs.

Would love to know your thoughts on going from a 4.4 to 4.6? I've heard it really is a big difference... but you'd have a really good reference point.

+ where did you find a B46 motor?

The X5 is a beast with the 4.6 motor in it. I’m not sure how much of the huge power surge that comes in at 2800ish RPM is due to the motor, the 4.4 transmission and/or torque converter, or the fact that I’ve got the older M60 intake and N62 throttle body on it. I didn’t really think any of the mods through…just tossed them on as I was building the motor or things broke, based on what I was reading on the forums, etc. I actually tend to think BMW gets things “right” when the engineer these cars, but where’s the fun in leaving everything stock!?

The intake roar is great, the low end power in the ZF no-sport mode is strong, but a bit lacking. When i put it in sport mode it is a monster off the line however. I suspect the difference in stall speeds on the TQ has something to do with it too. Above 2800 rpm or so the motor pulls like a train compared to the 4.4.

I’ve got a line on an OE 4.6 intake that I plan on putting on the car to see if there is a difference. I’ll then use the M60 intake on the 4.4 I’m building. The X5 needs new injectors anyway so that will be an easy swap and make for a nice comparison.

I bought the 4.6 new from BMW 2 years ago. It was in stock and arrived as what we would call a long block, although BMW lists it as a short block in their parts system. The slip of paper that came with it said it had been assembled in 2017, if I recall correctly.