From November 2017 onwards, the CFRP driveshaft in the BMW M3 Sedan, BMW M4 Coupe and BMW M4 Convertible will be gradually replaced by an M specific driveshaft made of steel. BMW says this measure will create the necessary technical basis for meeting future statutory emissions requirements. At a later point in time, a petrol particulate filter (PPF) will be incorporated into the existing installation space in these models in major markets.
“The newly developed steel driveshaft has been designed to ensure the superlative performance and handling qualities of the BMW M3/M4 high-performance sports cars remain unaffected,” BMW says in a press release.
For production-related reasons, this pre-enabling needs to be carried out universally for the BMW M3 Sedan, BMW M4 Coupe and BMW M4 Convertible. This measure does not apply to the BMW M4 CS and BMW M4 GTS special-edition models.
The justification sounds like utter BS
Definitely.
It would be interesting to know the weight difference, the actual (technical) reason for the change, what advantages are gained and lost, and whether the CFRP can be retrofitted after the changeover.
Advantages? Reduced cost…
The reason is obvious! Legislation is currently going frency! After the Diesel scandal now the next round of emission limits regarding particles is approaching. The new norm is called Euro 6 C. None of modern direct injecting gazoline engines will meet the new norm, which will be in place in Europe september 2018 for new vehicles. Since F82 will be produced until 2020, it has to meet new Euro 6 c. Therefore it will get a particle filter installed … and if you look underneath a F8x you will see, that there currently is simply now room to install such a filter … so the driveshaft has to get much slimmer…
Even if the driveshaft was slimmer, what would be the purpose of placing a fuel particulate filter in the driveshaft tunnel? This makes engineering sense how?
BMW keep dulling down their cars after release. Happened to BMW i3 as well. CFRP parts became aluminium, performance reduced, motor mount not strong enough to handle the torque etc…
This, in addition to the dulling down of the standard models (to the point where it’s not reasonable), are probably the main things I don’t like about BMW.
clearly cheaping out
“The main challenge of carbon-fiber materials is still the cost,” says Florian Schek, BMW’s head of lightweight design and vehicle weight. “The cost is still too high, and it’s a difficult technology.”
http://wardsauto.com/2017-car-management-briefing-seminars/bmw-pricey-carbon-fiber-losing-some-appeal