X ///M Real Life Pics and Videos Thread (Bandwidth intensive)

[998M]

Great videos!

My opinion that the sound of a natural V8 is better than a V8 with TT is because the TT are between the engine and the exhaust. The change the sound of the big V8.

[LeMansX5]

Originally Posted by 998M

Great videos!

My opinion that the sound of a natural V8 is better than a V8 with TT is because the TT are between the engine and the exhaust. The change the sound of the big V8.

Rumor has it that BMW is working to improve exhaust note for 2011 model as part of technology transfer from F10 M5 research.

[life@8500]

Originally Posted by 998M

Great videos!

My opinion that the sound of a natural V8 is better than a V8 with TT is because the TT are between the engine and the exhaust. The change the sound of the big V8.

the basic sound of v8s can vary by type of crankshaft arrangemnt (cross vs flat plane) or by exhaust manifold routing/design.

i guess most people are referring to crossplane with normal routing of headers as "natural". this arrangement produces the traditional v8 "burble" due to uneven exhaust pulses. the "racing" v8 sound is than of flatplane - like a formula 1 - high pitched,even cadence. (or like a ferrari v8 which uses a flatplane crank).

bmw has routed the exhaust manifolds in the s63 in such a manner to create even firing pulses to turbos to minimize lag. the resulting sound is that of a flat plane ("racing") v8. bmw even alluded to this in original advertising describing the s63 motor as having a "fast revving" characteristic.

most of you may have seen these docs but i will repost

BimmerFile Archive Exclusive: The NEW ///M Motor in Depth

2010 BMW X6 M: Replacing Turbo Lag with Turbo Brag - Ingenius Exhaust Manifold - Automobile Magazine

the exhaust flap is there, i'm pretty sure, to reduce noise level. my 1996 ferrari 355 has such a device... turbos don't like back pressure so this would not have been added to increase torque. turbo motors work a bit differently to NA.

the turbo scrolls do muffle sound....i've had a number of cars which i ran with a competely wide open exhaust and the noise level was tolerable. you couldn't even try than with a NA motor even 500 cc- it's would be very loud. a wide open exhaust on the x5m will still have an even cadence and not the typical v8 burble.

there's typically 5-10% power to be gained by a free flowing exhaust but time will tell...i see stebro already has a system for the x5m.

you guys have a pretty neat machine in the x5m and x6m...enjoy.
btw here's one of my posts on ferraichat. flat plane crank sound for BMW X5M?? - FerrariChat.com

[LeMansX5]

X5 M driving on sand.