The 'Diiiiiiiiiiish' Sound

[Chatters]

OK, I've had it with speculation, can anyone give me a difinitive answer as to what makes that sound when you change gears in movies like Fast and Furious?

[Adam43]

The sound effects guy.

Are these turbo cars? (I haven't seen the film)

[redshoes]

Normally take your pick from either a tubo dump value (http://en.wikipedia.org/wiki/Dump_valve) or nitrous purge kit (http://en.wikipedia.org/wiki/Nitrous)

However in this case I'd go with Adam's first answer.

[Chatters]

Yeah but I've heard them in real life as well.

[StuiE]

http://en.wikipedia.org/wiki/Blow_off_valve

Basically it's for idiots that have to let everyone know that their car has a turbo.

My car doesn't have one, makes a quiet 'flutter' type sound when the air goes back through the turbo.

[Chatters]

Uh huh. Thanks gtr69. Some people can be show-offs if they want, some can be normal...

[neilap]

I think calling it showing off is a bit harsh. Its the blow off valve. Most of the times when you purchase an aftermarket turbo kit it dumps into the air. Yeah, it does not have to, but because some people like the sound and the fact its more simplistic makes it more popular.

[Truckosaurus]

My diesel Volvo makes a dump-valve woosh noise that is audible at lower revs (above which the engine clatter drowns it out)...

[nickyf1]

I have heard a few cars like that. Like a yellow skyline went like this:

CLICK, TSSSSSSSHHHHHH

[BertMk2]

It's not just 'idiots' that have them, turbo charged competition cars have them too - just listen to WRC cars, Rallycross supercars etc and you'll hear the turbo 'chatter' (a full grid of supercars is an awesome sound - the turbo chatter sounds great maybe I'm an idiot too )

[StuiE]

The 'chatter' is compressor surge, IE what you get for not having a BOV, my car does this, but because it doesn't yet have an intercooler (with an intercooler there is more air to run back through the turbo and air filter) it isn't very loud.

Plumb-back (factory type) can still make a little sound (reason they are fitted is to remove the chatter type sound), some say it can improve boost responce, I'm not so sure, but I'm not going to shell out A$200 to find out, my car didn't have them from factory anway.

[garcon]

My Impreza of several years back had lots of chatter and random burps and farts and wooshes. Didn't have an aftermarket dump valve though - just a road/race air filter...

It did have an aftermarket exhaust though. Sounded bloody brilliant at full chat!

[Quagmire]

Right, a blow off valve just releases boost pressure to atmosphere when you lift off the throttle, its the pressure build up infront of the throttle butterfly when it snaps shut, and the resulting vacuum behind the butterfly will pull open the valve, and release the boost to atmosphere. Without a dump valve the pressure will back up to the turbo and cause the turbo to stall, this is bad for the turbo and can snap turbo shafts.
Certain cars, like Scoobys and MR2 turbos require a recirc valve, which is similar but recirculates the boost rather than releasing to atmosphere. These are much quieter, only really noticable at high boost levels.
Certain dump valves, such as the HKS SSQV BOV are adjustable, and this is what my housemate has fitted on his 200sx, and its set to not release below around 12psi.
The other option, although more expensive is an external wastegate, which involves a wastegate not mounted internally in the turbo, but seperate, and when a dedicated boost level is reached it will open up and allow exhaust gases to bypass the turbo compressor completely. These sound awesome, like rally cars
Think i've got that all correct, the cars in f&f are turbo'd, except the civic & integra, but they sound turbo'd due to the sound of the eclipse being used.
Hope that helps