Compressor surge or flutter? - 1G-GTE

[chopshop85]

Thats flutter. When the throttle is closed the built up air pressure flows back through the spinning blades of the turbo which is what makes the noise. Harmless on low boost applications.

Surge is when the engine starts to make that noise whilst on boost due to the air pressure exceeding the airflow of the engines intake.

[Fastspoolsupra]

If it does that while you're on the throttle yeah. It's the 1g-gte 2.0 L6 right?

[5UPRAH]

@Fastspoolsupra Yeah 1G-GTE. Doesn't do it when on throttle. Was a faulty BOV. Fixed now

[tomjw7]

compressure surge

[shamil808]

I keep reading that BOV flutter is bad for an engine....but please explain why?

[frankyw729]

@shamil808 because its not releasing all the forced air out. so its mashing it inside your turbo instead of getting rid of it like its supposed too.

[kyle340ify]

@shamil808 its not bad, some noobs just say it is. the only bad thing it causes is backfire after gear change, which IMO is awesome cause poppin flames is for the cool kids

[InitialDirt]

compressor surge is flutter..

[5UPRAH]

@InitialDirt - wrong

[InitialDirt]

whats the difference than wise man

[5UPRAH]

@InitialDirt: quote "Axi-symmetric stall, more commonly known as compressor surge; or pressure surge, is a complete breakdown in compression resulting in a reversal of flow and the violent expulsion of previously compressed air out through the engine intake, due to the compressor's inability to continue working against the already-compressed air behind it....."

[5UPRAH]

"...The compressor either experiences conditions which exceed the limit of its pressure rise capabilities or is highly loaded such that it does not have the capacity to absorb a momentary disturbance, creating a rotational stall which can propagate in less than a second to include the entire compressor...."

[5UPRAH]

".....The compressor will recover to normal flow once the engine pressure ratio reduces to a level at which the compressor is capable of sustaining stable airflow...."

[5UPRAH]

"....If, however, the conditions that induced the stall remain, the return of stable airflow will reproduce the conditions at the time of surge and the process will repeat.[1] Such a "locked-in" or self-reproducing stall is particularly dangerous, with very high levels of vibration causing accelerated engine wear and possible damage, even the total destruction of the engine...."

[5UPRAH]

I've you're still un-sure - perhaps use the googles! :P

[blyndrotor]

If you all want to see what real compressor surge is look this up.

True Compressor Surge

This is what real (bad) compresor surge is.

With good oil & regular maintenance this sort of (alleged) compressor surge is quite minor & not a MAJOR concern. Lets face it, for any minor effects it may have on turbo life, if you're modifying in any real way you'll probably be upgrading the turbo at some stage anyway. So many vids here with the keyboard racers/tuners who think this is horrifically bad.

[galumalemana]

Basically its compressor flutter wear the compressed air is not released through the release valve but redirected the waste back through the turbo propellers making your turbine lifespan short and performance limited

[metalseanhead]

You guys are idiots, surge sounds cool but it can actually kill your turbo.

IF you don't sort it out though it will split your compressor wheel nut off, which destroys the thrust bearings and bends the compressor blades backwards.

SO you guys are dicks for not sorting out compressor surge when it occurs. you don't deserve a car if you want to destroy it cause it sounds cool to do so.

[RXHardstyle]

flutters the same thing as a fuckin surge my god. people use the word flutter wen a wastegate goes off. but thats a surge for sure not gooddd

[AutoEth]

dont matter wut it is a bov will fix it even if its surge or flutter....

[peeonu25]

its assume so... i mean the point of a BOV is to release the pressure... pressure and a closed intake plate causes a surge... which is a flutter.

[beestonbash]

surge me thinks

[zacca417]

flutter mate surge is completely diferant happens when load bearing not when u take ur foot of go pedal , both harmful surge is just worse because it happens underload flutter can fuck ur turbos but ur unlucky if it does (manly happens with high boost)

[beestonbash]

cheers m8

[ki11joy92]

yea, just buy a bov, [even though that it sounds tight its very bad to not have one]

[unarmedblakman]

dude. compressor surge is just air that goes pushes back on the compressor side of the turbo because of high pressure in the intake due to the fact that your turbo is still spinning and still forcing air inside after the throttle plate is closed. ez

[cienciadecomputadora]

I Agree.

[samelod]

compressor surge is usually caused from the throttle plate closing quickly. flutter is..when the bov opens just a lil too late so that the turbo flutters until it finally open. oh well its about the same thing

[smok74]

Do you have a clue WTF youre on about ????? obviously not.

[initialmoe]

First of all Compressor Surge and Flutter is the same thing!

Second Yes it is very bad for the engine and the Turbo.

[APontiacof455cubes]

@initialmoe Surge is when ur on the throttle and ur wastegate stops effectively bleeding off boost and instead goes back into the turbo, causing it to surge. Flutter, is when u let off the throttle, and ur BOV fails to effectively rid of boost on the intake side, going back into the turbo and causing that sound

[Thug0000069]

BOTH!

[sr20det414]

the spring on your blow off valve is too stiff thus creating compresor surge i dont have a blow off valve myself but i suggest you get a greddy blow off valve because you can adjust the spring on those blow off valves

[jackrigbybitch]

mate all that is from is you'll find a small bolt on the back of your blow off valve, unscrew that a little bit (not so it falls out, but it will be over an inch long so unscrew it quite a decent ammount) so it reduces the spring pressure inside the blow off valve and it'll let the air flow easier. :) message me if you need anymore help.

[5UPRAH]

Thanks for your suggestion. I had wound it out as far as it would go. I've since rebuilt the BOV and changed turbo.

[pennywortdrink]

Falconman and everyone else that belives what they read on Wikipedia, don't. Anyone can write and edit, even if they are in fact, wrong. My mate "edited" something and it stayed wrong for quite some time until someone changed it back.

[falconmanf16]

Go to google, and type wastegate. Click on the wikipedia link, which should be the first link on google. On wikipedia, scroll down to the part that says wastegate chatter myth. It will explain all about compressor surge and all of that. I respect peoples opinions, but sometimes everyone wants to be informer or feel like that king of car knowledge, and then people start disrespecting commenters. Just google it.

[scrimlol]

comp surge is when your intake is too free flowing, or your turbo is too small and you will get a fluttering sound when you are on a certain amount of throttle (changes depending on each car)

Flutter is where you back off and compressed air hits the turbo blades and makes that sound.

[tuor1984]

Wrong.

[gwadd85]

its simply when your turbo puts out more air than your engine can use, so the compressor surge is when the air is forced out through the turbo backwards because thats the only way it can escape

[JoseGarciaElCeviche]

exactly so the air goes backwards to the turbo and the turbo bearings( or what ever theyr called) start spinning the other way

[gwadd85]

yea htat's what i said

[cienciadecomputadora]

The turbo cant spin to the other way. Is just the air scaping between blade.

[cossiedrifter]

So when you let of the throttle the BOV will not open enough to release all pressure and therefore the boost that didn´t escape through the BOV will surge in the turbo! And if you ask me I say compressor surge will NOT! damage the turbo and it will not increase turbolag! I haven´t noticed any difference on the cars I´ve driven without a BOV anyway! And some tuners will even say the car will run better without a BOV!

[cossiedrifter]

But the same turbo can make different sounds depending on when you let off the throttle, if you let off on low revs when it is on low boost it will make a different softer sound than if you let off on high boost! You can often hear flutter and surge on cars with high boost because the spring in the BOV has to be very hard, because if it isn´t the BOV will leak boost pressure.

[cossiedrifter]

A small turbo and high boost will give you the sound that you hear on the WRC rally cars! and a big turbo will give a much more low pitched sound like the sound you can often hear from a car like the Supra with a big turbo and high boost!

[norcotorrent05]

thats flutter and it sounds lush! nice car!

[2JZEDDIE]

BOV GONE WRONG HAHAAH

[aKaZaRiN]

It's flutter and you should be fine. A compressor surge is noiser and sounds a smidge different.

[cossiedrifter]

Flutter and Surge is the same thing! The sound depends on the size of the turbo and the boost!

[aKaZaRiN]

Um no there both different.

[bnz500]

lol

[aKaZaRiN]

Seriously there diff :P

[bnz500]

"Compressor surge" is the technical term for it, "flutter" is just the sound that it makes. Just like "chatter" or "dose"

[aKaZaRiN]

naw Flutter is harmless Surge is actually when the BOV cant handle the boost and cant shut its compressor fast enough resulting in a power leak

[5UPRAH]

What the? What are you talking about???

[aKaZaRiN]

What part do you not get.

[5UPRAH]

all of it - it doesnt make sense at all.....

[funfuckerhaha]

what the hell is a power leak? lol you make no sense at all! but it's funny though.

[BoostedXR6T]

power leak is when yer pushin' yer piss out real fast. thats power leak

[funfuckerhaha]

lol thats is a power leak!!

[HEKTIC458]

Flutter

[Stormchaser2be]

Thats a flutter..this is normal

[tsd1217]

flutter.

[5UPRAH]

Check out my "dyno" video - in the video I have a different turbo but with the same BOV. The BOV in the dyno video IS venting - but seems a little "slow" to open hence the "squeak" as the dyno guy backs off but then it goes away as the BOV opens....

[blanceemt]

it's flutter, surge only happens when your making too much boost and the engine cant flow it... and WOT, not when shifting

[5UPRAH]

Or when shifting. The turbo's still doing 100,000+rpm and pumping through a lot of air when you slam that throttle shut. Without a working BOV, you'll get comp surge

[blanceemt]

no... that's flutter. "surge" is when you have a MASSIVE turbo making too much boost for the flow characteristics of your intake manifold and head, all while making exhaust flow faster than intake flow... so you've got two sources competing on a common shaft. you CAN NOT have surge if you don't have exhaust gas flowing. the term "SURGE" is just used incorrectly by just about everyone out there :(

[blanceemt]

see the vid "406whp/281wht Stock Sleeve Turbo D16z6" next to yours? that's surge. lol i think he's the only person on youtube that uses the term correctly.

[5UPRAH]

Around the 44 second mark while he's still gunning it?

[intense98rt]

Its reading time with Corky Bell, please open to pg20 of your maximum boost books.

What is compressor surge, and how can it be countered? Compressor surge is the rapid fluctuation of turbine speed caused by the throttle's being closed under boost. Rapidly spinning turbos can go unstable briefly when this occurs. The fluctuating speed can be damaging to the turbo....

[5UPRAH]

You CAN have surge if you dont have exhaust gasses because the turbo is still doing +100,000rpm and pumping out a lot of air. If that air has no-where to go.....

[blanceemt]

it's. called. flutter.

[vlturbo88]

put a pipe on the mouth of the turbo and it makes the compressor surge loud as and it sounds sik haha

[DKandrew]

Hi, did you find out if this was Compressor surge or just the BOV, because Ive got the Monza on my STi and It makes exactly the same noise.... Did you manage to fix it?

[5UPRAH]

It was surge - I took the BOV apart and applied silicone sealer to the rear seal - this seemed to fix it.

[5UPRAH]

As it turns out I think the Monza is too slow to re-act. I did fix it then I put a bigger turbo on my car and now it's doing it all over again. Check my dyno video for what it sounds like now...

[DKandrew]

Haha mate, as they say you get what you pay for..Sounds like you should get yourself a proper genuine BOV, solve all the problems

[5UPRAH]

Yeah I will see if I can get a decent one from somewhere. But I have no money for now. Thanks :)

[jyturbox]

i believe thats a compressor surge, but i thought the hks and the type -s bov relieves compressor surge or something.. oh well but hope every things works out fine..

[rachitron]

no it doesnt, unless you set the spring to the tightest setting.

it's not a bov, it's compressor surge

[metDavidzelf]

what's the difference between flutter or surge and is is BAD for my Audi TT 1.8Turbo?

[rrsted]

compressor surge mate i had a hks ssq on my mates gsr and it done the same due to the bov spring being too tight.

[MazdaBp26]

by the way can you post a video of your bov?

[MazdaBp26]

no need for welding.. just unhook your waste gate hose.(the nipple in the turbo connected to the wastegate) andconnectthat to a boost guage, then try to boost 3 psi and see what happens.

[5UPRAH]

HAH! If only it were that simple. At present my wastegate runs off the plenum (I know, not ideal and will be moving it). I will be getting a fitting welded onto shortly after the turbo for the wastegate, so will use that for the bov test!

[5UPRAH]

Its a very tricky one. In the video I change from 1st to 2nd at the start, then feather the throttle in 2nd so you can hear it a few times. At the time I was boosting to 2-3psi. When I boost to 6-7 it makes that noise for half a second, then the BOV vents, then it flutters again for a second after the BOV has vented.

I've wound the BOV all the way out.

I'll have to get a fitting welded onto an intake pipe after the BOV so I can get that reading you talked about. Thanks!

[MazdaBp26]

that sir dont sound like a compressor surge.. =D best way to check if its a surge connect a vac guage on one of the pipes and drive it. youll probably see 0 hg but when you boost you should see 5 or whatever boost your getting, when you take your foot of the gas and see the needle. if it flactuates, its a surge , if it didnt its fine... make sure you plug it closest to the turbo..far away from the bov..