Hey guys,
Here's an in depth read about the exhaust and the challenges of exhaust note with turbocharging!!
http://f80.bimmerpost.com/forums/showthr...p?t=979417
Here's an interesting quote.... Reason for the CSL's dinner plate swivel air intake valve:
A naturally aspirated engine has relatively unobstructed lines both from the air intake and to the exhaust systems. A small proportion of the sound that the driver perceives as an acoustic indication of the engine load level in the interior of the vehicle comes from the direct transmission of structure-borne engine noise, while the majority of the noise is transmitted through the air directly from the intake tract; however the noise level is damped to an extent by a combination of the long intake distance and the air filters. In the case of a naturally aspirated engine, this damping can be decreased further by fitting a larger valve to the air box, thus acoustically dethrottling the air intake – as is the case in the BMW M3 CSL for instance. The resulting acoustic effect is very positive.
Here's an in depth read about the exhaust and the challenges of exhaust note with turbocharging!!
http://f80.bimmerpost.com/forums/showthr...p?t=979417
Here's an interesting quote.... Reason for the CSL's dinner plate swivel air intake valve:
A naturally aspirated engine has relatively unobstructed lines both from the air intake and to the exhaust systems. A small proportion of the sound that the driver perceives as an acoustic indication of the engine load level in the interior of the vehicle comes from the direct transmission of structure-borne engine noise, while the majority of the noise is transmitted through the air directly from the intake tract; however the noise level is damped to an extent by a combination of the long intake distance and the air filters. In the case of a naturally aspirated engine, this damping can be decreased further by fitting a larger valve to the air box, thus acoustically dethrottling the air intake – as is the case in the BMW M3 CSL for instance. The resulting acoustic effect is very positive.