You know this sound… you’ve heard it on the streets and probably wondered WTF? You know it comes from a sports car (and even buses!) but… what on earth is it?
The distinct “dose” or “pigeon” sound that flutters like “suuuuutututututututu” has many fans and many haters, it is a byproduct of turbo cars and many owners modify their cars just to get this sound.
The sound is so popular that it’s even invented one liners like “got sik flutters bro?” and “flutters get the chicks”, not to mention the majority of us making the “zzzzzzz tututututututu” sound on our own… yes I’m one of them (Jay: even my sneeze sounds like flutter).
So now that you know what sound I’m talking about and you’ve made your own attempt at the sound, let’s get down to the nitty gritty.
What is the actual flutter sound?
It’s air… lots of it being released out the air intake side of the turbo.
Why does it happen?
At the most basic level, turbo cars suck in massive amounts of air on open throttle hence the turbine sucking “zzzzzzzzZZZZ” sound. When the throttle is suddenly closed on a gear change or deceleration, the left over air that doesn’t get ingested by the engine needs to be released somewhere. That somewhere is via the Blow off valve (BOV), and in doing so can make a soft “PSSHHH” noise.
However when the BOV is removed from the equation (explained in the video and further down) and the pipes that were once connected are blocked off properly, the air has no other escape path except to travel back to where it came from… out the air intake resulting in this unique and sexy “Tutututututu” sound.
Why does it sound like there’s a pigeon stuck in the engine?
Best to check if there really are any pigeons stuck under your bonnet… but really the chopping effect of the flutter/pigeon sound – the “tu-tu-tu-tu-tu”, is actually the air bouncing between the closed throttle and spinning turbine wheel as it gets pushed out the direction of the air intake.
The slower the turbine wheel is spinning (resulting in low volumes of slow moving air in piping), the slower the chopping sound will be which results in a better and clearer flutter sound… this is experienced by releasing the throttle on light acceleration. After heavy acceleration however, the massive amounts of compressed air leftover in the intercooler piping (since it sucked in so much on open throttle) will reverse out quickly through the still spinning turbine wheel resulting in more of a whoosh sound with a slight flutter instead.
What do I need for flutters?
Besides a turbo car, you don’t really need anything. What you don’t need however, is the Blow off valve (BOV) that came fitted to your car from factory.
Manufacturers included them as a way to recirculate the surplus air mentioned above back into the engine to minimise both noise and emissions. Even though some cars do make a subtle flutter noise with the factory BOV in place (mainly Nissan engines), you’d really need to bin it in order to get some good audible flutters.
Highly desirable items that will amplify the flutter noise are an alloy/metal intake pipe and a pod filter attached to the end of it like this:
Why the intake pipe? Because sounds are amplified, reverberating off a metal pipe compared to rubber or plastic which has none of those properties. And the pod filter? Well because you want the sound outlet to be exposed and not muffled in the stock airbox.
So… will sexy flutters get me the chicks?
This should be the sole deciding factor as to whether or not you go down the flutter path… no really.
Being the truth seeker that I am, I asked the opposite sex for their opinions… here are the results:
66% of the sample group thought it was cool!
33% of the sample group thought it was lame… (maybe they like N/A)
So there you have it… majority of females do think turbo flutter is cool!
So what are you waiting for? Turn your ride into a chick magnet now!
(Disclaimer: sample size may not be indicative for rest of the female population. Also having turbo flutter may not guarantee attracting the opposite sex. And finally making the “tututututu” noise yourself won’t get you anywhere).
Don’t full atmospheric BOV’s sound better?
Have you not learnt anything? Flutters get the chicks! “Dose” sound is better than anything else and that includes “Pisssshhhhh” and human flutters.
Are flutters damaging to the turbo and/or other engine components?
Million dollar question that has a billion shades of grey all over it. All you need to do is do a search and read the countless threads on forums that debate over this question to realise there is no black or white answer. It doesn’t help either that top tuner cars like the HKS S15 drift car or Mines R34 GTR run no BOV while some rally cars do.
Whilst running no BOV to achieve flutter may put slightly more wear and tear on turbos, there’s no solid evidence out there that it will outright bend fins and break your turbo. But when you think about it logically for a moment… if you’re running massive boost (say above 2bar), it would make sense to dispose the copious amounts of highly pressurised air somewhere else instead of reverse path through a spinning turbine wheel.
It is also worth noting that your car may shudder or stall if modded for flutter as the stock ECU can go a little crazy after seeing the unexpected air in the intake. This isn’t that noticeable on Nissans but others aren’t so lucky (like Evo’s) and need a ECU retune to fix this problem. Be sure to do your research first!
Does trak-life like and condone flutters?
Jay and I are running a no BOV setup and have no gripes with it. Personally I actually disliked the sound and the slight shudder feel on flutter but have gotten used to both over time… it’s a much sexier sound than my previous Blitz DD and HKS SSQVII BOV sounds.
In the end the flutters don’t really offer much in terms of functionality but it also doesn’t degrade anything so I’m happy to leave it as is… besides, Jay loves Pearl’s flutter… so much that she sounds like she ran over a flock of pigeons and turkeys whenever he takes her for a spin… stop wasting my fuel damn it!
Do you think flutter is awesome too? Does it get chicks? Let us know below!