Quote:
Originally Posted by SeanWRT
Parts cost difference is negligible, tuning cost isn?t that much either. The real problem in using B58 turbo is that it?s not a bolt on replacement to N55 turbo. This is what really BMW doesn?t like - to engineer, open tooling for and manage all these new M2 exclusive parts - exhaust manifold, intake plumbing probably including an IC redesign. They may as well put in a detuned S55 and call it a day, which is what?s happening right now to M2 CS/Comp or whatever they call it.
It doesn?t take a broken engine to call it unreliable. Reliability is more about how less often you will have to send in your car to dealer to fix problem, bigger or smaller.
You heard 4 major reliability issue with N54 - HPFP failure (under stock boost), water pump failure, turbocharger rattle(wastegate bushing wear out) and intake valve carbon build up. These 4 issues aren?t the hit or miss ones, they WILL happen sooner or later, very very few n54 owners gets away with any of these.
When N55 PWG came out, all those issues except for HPFP, are addressed. Since the arrival of EWG in late 2014, HPFP has been reliable as well (not to confuse this with HPFP failure under aftermarket tuning and ethanol). N55 is now essentially a more efficient, more reliable and less powerful (due to turbo capacity) version of N54.
M2 IAT management (not to be confused with engine oil/coolant cooling) is under-engineered because of cost saving from adopting M235i parts. Normally you?ll see a 20+F IAT climbing from your first 4th pull on dyno and things will get worse in repeated runs. When we talk about heat soak on dyno, really we?re talking about timing pull, normally. DME will decide at which point it starts to pull timing. To our experience, timing pull becomes noticeable enough from 125F. Therefore on a dyno, it is the ambient temp and fan flow capacity that dictates how long you will get there. Before you get there, you will not see gains from bigger IC. Probably you will lose a little bit power with bigger IC because normally it has more pressure drop which DME sometimes isn?t capable of compensate. Real world drag testing prove this very well. Especially when you do 1/4 mile, it reach the point where you have to balance cooling and flow capacity of FMIC.
Many say cooling are much better on stock FMIC in real world because you get enough flow. Typically that?s what happen when what they do is just one or two pull from 60-100mph and cruise 70mph for a few 10s and pull again...That?s not remotely pushing hard. Do a HPDE and you will know. Or do two consecutive 1/4 mile pull (just brake hard to stop and no break in between at all), m2 will see heat soak BADLY right away even in winter. That?s what I know last year |
So much for the "Track Cooling" advertised by BMW then huh. For all the praise that the M2 has received, there are some real weaknesses there.
Still makes no sense that they would drop in the B58 to the M240i while keeping the N55 in the M2. I guess the overwhelming demand for the N55 M2 made it unnecessary for them to put in the effort.