Z3 M Coupe Differences
Discussion
The S54 engine is out of the E46 (current) M3, whereas pre-2001 Breadvans (that's M-Coupes) had the S50 engine from the E36 M3.
The S54 is de-tuned from it's M3 application (down to 325bhp from 343bhp), and consequently it's very reliable. It's a generation on from the S50 so it's less peaky and more flexible. It's also 50cc bigger (yeah!).
The S50 was (or so I'm told) prone to developing a problem with the variable valve timing system (VANOS). IIRC the drive cogs became worn fairly easily, initially resulting in a grating noise (a reasonably economical fix). If left untreated the system failed all together, resulting in piston-valve strikes and a rebuild incorporating lots of new parts (a reasonably bankrupting fix!).
Apart from the engine the S54-equiped cars get stability control (which you'll need!), tyre pressure monitors and a lot of other "facelift-esque" tweaks in trim.
The S54 cars are apparently noticably better, but then they cost quite a chunk more. But on the plus side you can get them in Phoenix Yellow, which is "the bomb"... apparently.
More info can be found here
The S54 is de-tuned from it's M3 application (down to 325bhp from 343bhp), and consequently it's very reliable. It's a generation on from the S50 so it's less peaky and more flexible. It's also 50cc bigger (yeah!).
The S50 was (or so I'm told) prone to developing a problem with the variable valve timing system (VANOS). IIRC the drive cogs became worn fairly easily, initially resulting in a grating noise (a reasonably economical fix). If left untreated the system failed all together, resulting in piston-valve strikes and a rebuild incorporating lots of new parts (a reasonably bankrupting fix!).
Apart from the engine the S54-equiped cars get stability control (which you'll need!), tyre pressure monitors and a lot of other "facelift-esque" tweaks in trim.
The S54 cars are apparently noticably better, but then they cost quite a chunk more. But on the plus side you can get them in Phoenix Yellow, which is "the bomb"... apparently.
More info can be found here
Uber. At the time the reason for the power reduction on putting the engine in to the Z3M out of the new M3 was claimed to be the exhaust system which had to be designed in a restrictive way to fit in.
However is that true at all? Did they know that the Z4M would be using the same engine in future (fairly likely) and therefore not want it to have the same full 339bhp?
BMW M aren't usually ones to build lots of different versions of their engines - see how the Z4M's six appears to be identical to the one from the E46 M3, even though it's now a 7+ year old engine, they haven't even updated it with a slight torque increase or mild power increase or anything.
However is that true at all? Did they know that the Z4M would be using the same engine in future (fairly likely) and therefore not want it to have the same full 339bhp?
BMW M aren't usually ones to build lots of different versions of their engines - see how the Z4M's six appears to be identical to the one from the E46 M3, even though it's now a 7+ year old engine, they haven't even updated it with a slight torque increase or mild power increase or anything.
pentoman said:
Uber. At the time the reason for the power reduction on putting the engine in to the Z3M out of the new M3 was claimed to be the exhaust system which had to be designed in a restrictive way to fit in.
However is that true at all? Did they know that the Z4M would be using the same engine in future (fairly likely) and therefore not want it to have the same full 339bhp?
BMW M aren't usually ones to build lots of different versions of their engines - see how the Z4M's six appears to be identical to the one from the E46 M3, even though it's now a 7+ year old engine, they haven't even updated it with a slight torque increase or mild power increase or anything.
The S54 is 5 years old, and the reason that there power in the Z4M is still the same as in the E46 M3 is that the engine has got nothing left to give! However is that true at all? Did they know that the Z4M would be using the same engine in future (fairly likely) and therefore not want it to have the same full 339bhp?
BMW M aren't usually ones to build lots of different versions of their engines - see how the Z4M's six appears to be identical to the one from the E46 M3, even though it's now a 7+ year old engine, they haven't even updated it with a slight torque increase or mild power increase or anything.
They only bored out the S50 unit by an additional 50cc because that put it right on the limit of cylinder wall thickness (or rather thin-ness). And quite a few of the early E46's had their engines go bang because they are so highly tuned, so they obviously didn't want to risk it any further.
In the Z3M cooling and exhaust issues made the restriction necessary, as there wasn't sufficient space for an adequate radiator or silencers. The Z4M is a bigger car, so it's got comparable space to the E46 for cooling/exhaust (but not SMG interestingly).
The M3 CSL's unit has 360bhp, but that's only with the use of a carbon-fibre induction unit and trick exhaust, both of which contribute to it's massive price tag. It's doubtful if either would fit the Z4M.
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