So, I posted this topic in the FM6 thread around a year ago:
Originally Posted by: V8 big blok 
My favourite parts about racing games is the audio and it's design. Forza has always had some great sounding cars in general over the years. Great exhaust notes,engine notes,turbo/bov effects and supercharger whines.(still room for improvement but great overall).
However, one aspect that really needs some attention is the transmission modeling/simulation and other related things like better implementation of accel and decel loading. At the moment, the straight cut gear whine in Forza doesn't really sound or behave in a realistic manner. When coming off the accelerator then back on doesn't sound or behave in a realistic manner.
Here's some examples of what I'm talking about.
Real Life Z4pCars/iRacing/Raceroom Z4Forza 6 Z4So, notice the the real life and PC games straight cut gear whine. Also notice how the physics are implemented in accordance. Notice how the gearbox oscillates and judders when going through the gears as well as when coming back on throttle.(like there's actually a racing flywheel simulated). Raceroom in particular has probably the best driveline flex model seen in a racing game to date.
Here's another iRacing vid of the V8 Supercar.
iRacing V8 on/off throttle loadForza V8Again, notice how the on/off throttle loading/de loading sounds and behaves.
While I'm here lol, the exhaust/overrun effects can also be improved.
Forza 6 Lotus 77pCars Lotus 78The pCars version (I know, different cars but point still stands) certainly to my ears sounds more "racier" at least when off throttle and decel effects are concerned.
Anyway, I could go on and on but Ill leave it here. I certainly hope that Nick Wiswell and his audio team along with the physics team can deliver something special come Forza 7 time!
Now, I just heard Dan Greenawalt mention how they're trying to bring in a new style of audio where he specifically mentioned Driveline Flex!
A quick description of flex that someone on Neogaf forums posted:
"Basically, in any engine-powered vehicle, there's a bunch of joints and machinery delivering the power between the engine and the wheels, during which process the "flexing" of said parts means there's some power loss, some delay between the pedal input and power delivery, etc. There is never a true 1:1 delivery of the power the engine makes to the wheels because of all the machinery in the way."
In this video, you can hear the "jerky' or "juddery" driveline in action:
Ferrari F40 LMAfter listening to the recent videos from E3, finally, after so many years, Forza Motorsport finally features this phenomenon in the game beyond just an audio effect but now a
physics based audio effect!
Thank you Turn 10 for bringing that touch of realism and authenticity to the game!