Dose/Stutu/Flutter

[MindlessR33]

When I imported my R33 it had some turbo flutter. I always loved that sound and associated it with Skylines. I took the car to a shop, they looked it over, and one of their biggest recommendations was to take the block off the blow off and stop it from making the noise. We did so, car feels "better" but I think that's because the car was also just running on wastegate pressure and now it isn't. I'm just trying to get a consensus of how bad this is for the turbo? Seems like every video I watch has opposing opinions. Can't get a solid answer. Motive says one thing, TRC says another, MCM says something else, MCM2 says another. If it's not going to kill the turbo I'm going to bring back the dose. If it is then I'll stick with the pshhh instead. I'm just totally new to turbo cars. I'm happy either direction, but somewhere deep in my soul I'm itching for that sweet stututu.

Video is the day I brought the car home, and how it sounded then. 

[r32-25t]

Americans think it kills turbos, Aussies don’t think it does. You do which ever one you want cause it’s your car 

[MindlessR33]

3 minutes ago, r32-25t said:

Americans think it kills turbos, Aussies don’t think it does. You do which ever one you want cause it’s your car 

simple enough

[admS15]

@Dose Pipe Sutututu    This guy wants to know about dose, your expert opinion is needed. 

 

[Kinkstaah]

I mean it doesn't necessarily instantly kill the turbo.

But there is a reason the people who made the turbo even made a blow off/recirculation valve. There is a reason all? turbos in any performance car have these valves.

[Ben C34]

6 minutes ago, Kinkstaah said:

I mean it doesn't necessarily instantly kill the turbo.

But there is a reason the people who made the turbo even made a blow off/recirculation valve. There is a reason all? turbos in any performance car have these valves.

Ultimate turbo performance car doesn't have one. (vl turbo)

[Dose Pipe Sutututu]

Run big FMIC, long pipe work, delete the AFM and install an intake pipe that's long to increase dose.

Delete the BOV, 100%.

Not mandatory for cars running low boost, you're not going to blow off any cooler pipes when thr throttle closes or bend ang throttle plates.

[Dose Pipe Sutututu]

Thr shit box when I first picked it up, needed to make it dose to be a mad karnt.

 

[Shoota_77]

19 hours ago, Dose Pipe Sutututu said:

Thr shit box when I first picked it up, needed to make it dose to be a mad karnt.

 

You bin workin' out?

We can see your cleavage.

[Dose Pipe Sutututu]

48 minutes ago, Shoota_77 said:

You bin workin' out?

We can see your cleavage.

That was 7+ years ago, rocking the wannabe dad body now.. also I'm married and no more music festivals to walk around shirtless & flex to the bishes

[Shoota_77]

Ha ha, dad bods are where it's at!  Love to say I've spent ISO getting rid of mine but no.....

[mosquitocoils]

I've never known nor do I claim to know. However I am building my Stagea specifically so it can dose and be as loud and obnoxious as possible...

???

[robbo_rb180]

57 minutes ago, mosquitocoils said:

I've never known nor do I claim to know. However I am building my Stagea specifically so it can dose and be as loud and obnoxious as possible...

???

Your doing it wrong then need to get a harley to be loud and obnoxious like @mlr ?

[mosquitocoils]

2 hours ago, robbo_rb180 said:

Your doing it wrong then need to get a harley to be loud and obnoxious like @mlr ?

Oh man that's quite ironic, I actually swapped my straight piped de-restricted Kawasaki ER6N for my Stagea... My ears definitely thanked me for that trade!!

[Dose Pipe Sutututu]

Maximum dose can be had with a 6+6 GT style compressor wheel, the new 11 or 12 blade GTX style compressors don't dose very good. Going to a GTX Gen 2, my dose has dropped.

[TurboTapin]

I highly doubt every automotive manufacturer is designing and adding parts (Recirculation Valves) which cost them extra money and complexity just for the fun of it. Same applies for Turbo manufacturers recommending them when they don't even sell them (Garrett, etc.)

 

  

[Dose Pipe Sutututu]

Of course they have their purpose, they aid in transient response, help with driveability (OEM BOV has a bleed port), reduce noise, etc.

However, most turbo owners live for whoosh and sutututu noises.

Disclosure: I'm planning to install a BOV to my car to reduce the likelihood of cooler pipes being blown off as I'm running 2bar of boost.

 

[GTSBoy]

1 hour ago, TurboTapin said:

I highly doubt every automotive manufacturer is designing and adding parts (Recirculation Valves) which cost them extra money and complexity just for the fun of it. Same applies for Turbo manufacturers recommending them when they don't even sell them (Garrett, etc.) 

Compressor bypass valves (to give them their correct name) are mostly intended to allow air to go around the compressor in the forward direction, whilst under vacuum, to reduce (frictional pressure) losses and increase the breathing ability of the engine and hence gain boost a tiny bit earlier.

[joshuaho96]

I have heard in very exceptional cases some turbos need BPV/BOVs because the shaft holding the compressor wheel was undersized and couldn't take the loading from going in/out of surge and would snap it clean off. But that was a band-aid fix for a mistake in the design phase.

[TurboTapin]

58 minutes ago, GTSBoy said:

Compressor bypass valves (to give them their correct name) are mostly intended to allow air to go around the compressor in the forward direction, whilst under vacuum, to reduce (frictional pressure) losses and increase the breathing ability of the engine and hence gain boost a tiny bit earlier.

Nissan calls them recirculation valves, and this being a Nissan forum I'll stick with that but their patents have a variety of different names. Speaking of patents, they also describe their purpose. Here's a portion of text of one of hundreds of different patents. 

Cheers. 
 

Patent US10077709 

FIELD OF THE INVENTION

The present invention relates to diverter valve systems used with turbocharged or supercharged motor vehicles.

BACKGROUND OF THE INVENTION

Most modern turbocharged vehicle engines include some form of factory-fitted blow-off or bypass valve in the intake tract, the purpose of which is to open during throttle closure to provide a relief path from a diversion aperture or pressurised air that would otherwise cause significant pressure spikes, resulting in damage or reduced life-span of the turbocharger, and also an unpleasant fluttering noise that is deemed unacceptable in a road-going passenger car.

There is also a potential performance improvement, in that without a relief path, rapid throttle closure and the resulting pressure spike can rapidly slow the turbo compressor, leading to a longer delay in returning to peak boost when the throttle is re-opened (i.e. increased turbo lag). Similarly, allowing the bypass valve to relieve too much pressure can also have an adverse effect on turbo lag—evacuating the entire volume of the intake tract means that despite maintaining a higher compressor speed over the short term, when the throttle is re-opened the intake tract must be re-pressurised which causes an increase in lag.

 

Edited August 31, 2020 by TurboTapin