Air intake - how do I get turbo flutter?

[Scottie]

Of course a BOV is going to prolong a turbochargers life. It is what they are designed for. If you block up the BOV on a Legnum/Galant you still wont get bugger all flutter. There are many other things that contribute to flutter.

Some race cars but more commonly drag cars do not run BOVs because they only operate then there is negative pressure from the throttle closing. How many drag racers do you know that take their foot off the pedal when they are going down the quarter? Also, a BOV on a drag car is just another thing that can leak and cause problems.

 

[steveP]

still waiting on studies conducted so theres some actual proof to this myth..

 

[mustang21]

Im placing my vote with the BOV, the air rushing back will damage the turbo.

but dont get me wrong, fluter is sexy.

 

[Scubasteve]

Flutters

Or put on a HKS Super Sequential Blow Off valve

Makes the sound you're after when you shift without damaging the turbos

Psssssshhhh-ptsh-tsh-tsh-tsh

I own a petshop and can get u those pidgeons for alot "cheeper" than that blow off valve.
lol hope it helps.

 

[frozen]

christians doesnt seem to flutter with the super sequential?

 

[pu-11-me]

Lol @ James

Flutter through a VTA blow off valve is caused by variations in plenum pressure when the throttle is released.

It happens MORE with bigger single turbo's as they don't slow quickly enough creating minor amounts of pressure in the system between the BOV opening then closing, then pressure builds as the turbo slows, BOV opens etc etc (Can happen a few times in less than a second!)

Josh, it DOES do it on ours rarely, but you have to get the right rev and release combo to do it. The reason the sequential valves are more prone to doing it is because of their dual action. Mine does it occasionally. When least expected actually haha

Anyways, this post is long enough lol

 

[frozen]

hmm interesting.. i can get 'flutter' the traditional way of having my spring on my bov tight enough that it doesnt really 'open' till i have more than a few psi of boost happening.. if i take my foot off at about 1-2psi on the guage i get a small fast flutter sound pretty quiet though.. the more i replace soft piping with harder piping, the louder it seems to get

i might try borrow an ssqv off someone and see how it sounds lol. just not a fan of it opening up on ANY boost, i like the stealth factor of having a tighter spring and i can still boost up a bit, slowly take off my foot and it wont vent.. handy if you drive past cops with a bit of accelleration by accident..

 

[steveP]

^^^ ur not really getting flutter, just a bov that simulates it. and bov's dont open until ~5psi or more, so ur always gona get a bit of flutter with any bov.


2 or so months ago i removed my bov, got all the bits from the plumbing section in bunnings lol. those lil pvc end caps.

..and guess what, my car didnt blow up, the turbos didnt shoot out my exhaust, and the car didnt run a 9 sec pass down the 1/4 mile when turning the heater on.. OMG!

nothing happened, coz they arnt required.. well not unless u want ur car silent and stealth.. which car manufacturers DO WANT.

the car is still dead stock, but ive noticed when the car up shifts into a new gear u really get a kick in ur seat backwards. thats coz the turbos DONT need to spool up again, all the compressed air is still in the intake system.

also on my silvia, it never came with a bov, and the factory turbo lasted 15 years doing 130,000 kms until it gave way.. and that was because the oil feed line got blocked and staved the turbo.

i know its a old thread, and im repeating myself, and im not trying to be nasty.. but we shouldnt be discussing what people think or vote for.. we want facts of what bov's do and what affects they have.

 

[frozen]

any nice sounds happening now steve? let me know how it goes... cause i wouldnt mind taking mine off... 1 less defect, and still a cool sound lol

 

[Kenneth]

I can't be arsed arguing about it more, so I will post up a quote

"The BOV should
be installed between the compressor
discharge and the throttle body,
preferably downstream of the charge
air cooler (if equipped).
When the throttle is closed rapidly, the
airflow is quickly reduced, causing flow
instability and pressure fluctuations.
These rapidly cycling pressure
fluctuations are the audible evidence
of surge. Surge can eventually lead to
thrust bearing failure due to the high
loads associated with it."

Well, in case you didn't know, it comes from Garrett. Thats right, Garrett.

As you can see, they don't say it ALWAYS leads to thrust bearing failure, and for sure it won't likely happen immediately.
The fact is, Garrett spend a shed load of money designing, building and testing turbos. They know what causes failure, and it is printed there black and white.

This should be the end of the debate.

 

[steveP]

^^^ yeah i agree but..

what does garrett say about over boosting their turbos, running rev limiters, external wastegates, no heat sheild/wrap, braided lines, appropiate cooling devices, correct engine oil, even turbo timers. there are many things that will increase or decrease the life of a turbo. and in the spectrum of things, running no bov will do sfa.

any nice sounds happening now steve? let me know how it goes... cause i wouldnt mind taking mine off... 1 less defect, and still a cool sound lol

before i removed the bov, i fitted the pod filter to compare before and after induction noise. could barely hear anything with just a pod, maybe a quiet 'squeek' when the bov opened. with it removed, u defiantly get a tough induction sound and a woosh when backing off. see im used to my nissans with epic flutter lol. and its nothing like that, half as loud as my silvia at best of times. but at least u do get the turbo sound.

 

[OVR444]

So we are going for this sound?

 

[mills_88]

Ive seen that falcon vid before, can you imagine how annoying that would get driving to the shops. By time it stops tsh tsh tsh tsh tsh ing youll need to change gear again lol.

 

[matchtheclown]

Just stop screwing around and put the plumb back line of the BOV through a duck caller.
http://www.youtube.com/watch?v=VbNxugO-uf0

 

[OVR444]

Is there a "snorkel" as such that is used to quiet the intake sound? I know on my previous car it had a elbow that branched off to a large box type area to help decrease the intake noise.

No I'm not going to put a pod in my engine bay... I'm guessing upgrading to aluminum pipes would most likely be the only thing that would change the intake resonance whilst under spool/boost.

 

[timmae2006]

Josh, it DOES do it on ours rarely, but you have to get the right rev and release combo to do it. Mine does it occasionally. When least expected actually haha

I agree I try to get mine to do it and i generally happens when im not trying, lol or i boost hard get off the gas which releases pressure and almost instantly clutch it for a second release

 

[Tom]

With the RPW Downpipe fitted, I get a slight flutter sound when releasing throttle around 2500-3000rpm.. Sometimes I get a bit of it with my ptshh from the BOV.. sounds wicked, would love more flutter though haha Love that noise.. But I have no idea how I can get that going more!

I plugged up my BOV (I have 2 different trumpets and a plug for my StealthFX) and went around seeing what it'd sound like, but I get quicker response through gear changes and no flutter or BOV noise.. Which, I have no problem with of course, better response time = wicked

But I'm not racing people all the time on the roads, so some wank factor type noises never go astray haha..

Anyone actually have an answer for the original question on this topic? How to get turbo flutter.. I read through, and it seems to be opinions for and against, but no actual answer on how to go about it..

And if all these Nissans out there can have flutter and not seem to DIE from it, I'm sure it isn't as bad as some have said..

 

[steveP]

like i think i said before..

1. pod filter.
2. remove bov.
.. this will get ur some flutter/woosh/intake noise. like the car is sneazing.

for more flutter..
3. upgrade fmic.
4. stainless/aluminum piping. (fmic kit piping, and turbos to air flow metre).

 

[Tom]

Haha thanks dude..

I think I'll prob keep my BOV on though, having no BOV sounds like I'm going to mess up something! .. I don't know enough to really be too confident in doing that =/

 

[frozen]

just have one with an adjustable screw... and make it tight enough that it wont open on low low boost, but as soon as its got a bit more it will vent when you release..