Massive Turbo Flutter

[KF-]

Hey guys, My R33 has A massive turbo flutter problem.

the origional turbo has been replaced with a KKr430, I'm planning on buying A Greedy Bov for it.

I'm just wondering how bad the effects of turbo flutter is, how much it reduces the life of the turbo?

[inthisglass]

what bov does it have an it atm?

if your getting compressor surge from having the bov blocked off or something then id remedy it

but i wouldnt wory too much about flutter

its a kkr after all so it'll break soon enough anyway

[Hanaldo]

Lol ^

There is no evidence that flutter damages your turbo, so it is hard to say how much if any damage it would be doing. Personally i think it does damage the turbo, but if you are worried about it then just remedy it with a good plumb back bov

[saweeet4DR]

kkr ..wat bov "if so" r u currently running?,and i wouldnt worry bowt the flutter too much (that is unless u dont like it).I Had no bov on my old 180sx for nearly 5 years runnin a T28 running @1bar everyday and never had any problems at all and luvd the flutter

[Nic_A31]

There IS evidence actually mate.

Ceramic turbo's last long under surge. Steel wheel as found in R33s can handle it, they'll usually end up with shaft play before the turbine blades go, either way it is bad for your turbo. The more boost the worse it is.

If you want to fix it straight away, either loop the intake to skip the turbo, if you have a boost controller - cut out boost altogether, and rectify why your blow off valve isnt opening.

[Hanaldo]

There IS evidence actually mate.

Ceramic turbo's last long under surge. Steel wheel as found in R33s can handle it, they'll usually end up with shaft play before the turbine blades go, either way it is bad for your turbo. The more boost the worse it is.

If you want to fix it straight away, either loop the intake to skip the turbo, if you have a boost controller - cut out boost altogether, and rectify why your blow off valve isnt opening.

It would be very hard to prove that compressor surge was the reason for any turbo failure, hence there is no actual evidence to demonstrate that. I know people that are running 12-14psi through ceramic turbos with no bov, and have been for years, yet their turbos still have very little to no shaft play. On the other hand, my mechanic showed me a turbo that he had been running in his R33 GTS-T for 40xxxkms and never fluttered, the shaft had way too much play.

Having said that, i am on your side, i believe it causes damage and should be avoided. I am just saying there is no physical evidence that can be solely contributed to compressor surge

Edited April 18, 2010 by Hanaldo

[Nic_A31]

Then what you claim is there is no evidence, in ANY case, regardless of any setup, to say that anything caused turbo death or extended its life. What would have caused it then ? stock turbo's don't blow teeth off...

Its highly likely that bouncing 10psi at 7 grand back onto ceramic blades will cause those blades to break free. Any that doesnt is simply a factory freak.

[Hanaldo]

That's the thing, it can't be proven beyond any shadow of a doubt. Personally i accept what evidence there is (eg. what you said above ^) as flutter is bad and causes damage. But as far as firm concrete evidence is concerned, there are plenty of stock turbos out there fluttering away happily. I forget what magazine it was in, pretty sure it was HPI because that's what i read most, but there was an article in there about testing done on a stock RB25 turbo where they literally fluttered it to death, and yes the blades blew sky high. But the final verdict was that the result was not conclusive because there were too many other factors. The turbo had already travelled 120xxxkms, and who knows how hard it had been pushed or how poorly it had been looked after. The fact that the wheel blew under flutter could simply be an indication that it was already damaged.

[Nic_A31]

Oh and Im guessing somebody will come back with "oh but Ceffies didnt have boV from factory and their ceramic turbo's last just as long" - yes, but factory turbo ceffies boost less than 5 psi... which is safe enough for ceramic, can probably handle a tad more. Steel wheel can handle alot more on top, but for "massive flutter" you need some seriously high pressure.

Edited April 18, 2010 by Nic_A31

[Nic_A31]

That's the thing, it can't be proven beyond any shadow of a doubt. Personally i accept what evidence there is (eg. what you said above ^) as flutter is bad and causes damage. But as far as firm concrete evidence is concerned, there are plenty of stock turbos out there fluttering away happily. I forget what magazine it was in, pretty sure it was HPI because that's what i read most, but there was an article in there about testing done on a stock RB25 turbo where they literally fluttered it to death, and yes the blades blew sky high. But the final verdict was that the result was not conclusive because there were too many other factors. The turbo had already travelled 120xxxkms, and who knows how hard it had been pushed or how poorly it had been looked after. The fact that the wheel blew under flutter could simply be an indication that it was already damaged.

This is probably where we're dissagreing.

What death exactly are you thinking of?

Im saying that high pressure going back towards a compressor will rip the blades off the wheel.

Immediately slowing down and speeding back up (surge) can cause the shaft to snap, or contribute towards shaft play, and shaft play / broken shaft can also be affected by prior life of the turbo (kms, oils used, treatment etc), such factors cannot possibly cause the blades on a wheel to come off ... that can only be caused by excessive feedback.

Edited April 18, 2010 by Nic_A31

[Hanaldo]

Yeh true, i was more referring to shaft play. Although could overboosting not weaken the compressor wheel? Lol... in any case, flutter = bad

[Nic_A31]

Yeah like I said, shaft play / snapping / any shaft drama' is caused by any or a combination of issues. Spinning at 200'000 or 300'000 rpm, then being forced to go the other way in less than half a second certainly doesnt help the shaft live a long and happy life.

[KF-]

Hey guys, thanks for the reply's.

It hasn't had an Aftermarket Bov installed so I'm guessing that its running stock if not, none at all.

so the Kkr isn't such a good turbo?

would you please suggest A turbo that would be a good replacement, here are my engine specs at the moment

Engine: Rb25Det

83000kms

KKr430 turbo

High Mount Stainless Manifold

38mm Wastegate

HKS AirFilter

Front Mount Intercooler

HKS HI Power Turbo back 3 1/2" exhaust system

Bosh 044 External Fuel Pump (in tank)

Iridiums

HKS Turbo Timer

Turbosmart Manual Boost

there's A link to my car, you can clearly hear the flutter

[bubba]

Wow, this thread is full of fail.

What has ceramic wheels got to do with failing due to flutter?

The ceramic wheel is on the exhaust side..

The returning air does NOT stall the turbo, and it does NOT make it spin the other way.

The only thing it will be doing is putting a bit of extra load on the fins of the compressor wheel as it tries to push air into the returning air.

Edited April 18, 2010 by bubba

[SKYRYAN]

Wow, this thread is full of fail.

What has ceramic wheels got to do with failing due to flutter?

The ceramic wheel is on the exhaust side..

The returning air does NOT stall the turbo, and it does NOT make it spin the other way.

The only thing it will be doing is putting a bit of extra load on the fins of the compressor wheel as it tries to push air into the returning air.

I agree with bubba, build a 25/30!

[bubba]

[R32 Driver]

search the forced inducted thread there must be a 1000 page discussion on fultter by now

[snozzle]

these threads pop up once a week these days, and yes bubba great advice on the 25/30 buahahahaha