I rebuild turbos for a living, and what they're saying is pretty much correct. The thing is though, certain turbos can take lots of surge, and others cant. Turbos like Holset's, Garrett GT37R's, GT40R's, or larger with beefy thrust bearings can take a lot of surge out of the box. Turbos such as TD05/TD06's, Borg Warner S200/S300/S400's, K24/K26's, Garrett T3/T4's etc can take surge as well as long as they have an upgraded thrust bearing. That's the one part of the turbo under stress when surging, the thrust bearing. On a turbo with a not enough thrust bearing journal area, the thrust bearing wears out quickly (because it is overloaded with thrust load and the oil film is squeezed away) and then you get loads of in and out shaft play. Then one day the compressor wheel tears itself apart by hitting the compressor housing. And another thing, turbo compressor nuts are threaded in reverse from the turbos direction of rotation, so they don't back off, they will only get tighter. Basically any OEM turbo is not designed to take the extreme thrust load from surging. Small frame steel ball bearing turbos will develop excessive shaft play from surge as well, ceramic ball bearing ones are generally okay. Bottom line is most properly built aftermarket turbos with 360 degree thrust bearings, or just plain ceramic ball bearings can take the load of compressor surge. If you surge your OEM turbo it will probably last a good 6 months to a year of daily driving, less if you're running more than stock boost.
go ahead, i dont have any tips there other than i personally like the tial q bov for its sound. obviously get a blockoff plate for the diverter valve and have the car tuned to a bov
It's the Aussie way. We love the turbo flutter. It's 100% about the sound! Does its damage the turbo? My opinion as a mechanic for 15 years and owned many turbo is no
The flutter (sututututu) noises are caused by the throttle snapping closed and all the air thats already heading to the intake gets stoped and fills up the intake pipes all the way back to the turbo, and forcing it way through the compressor fan while its still spining at its ridiculous rpm, forcing the compressor fan to cut through the air, thus making the flutter noise
so what do you guys think, with flutter caused by throttle closer as Jimmy points out above, would that hurt the compressor or not? If the BOV/BPC was set up correctly, I thought it should vent all that excess pressure between compressor and closed throttle plate, and there would be little to no air having to escape through the spinning compressor wheel, and hence no flutter?!
Thank you for clarifying, now i can show people this video instead of trying to explain why they're wrong. The only thing i noticed is that with no bov on my mr2 i actually had a MORE RESPONSIVE turbo while changing gears...when i ran a bov there was MORE LAG while changing gears at WOT. Thats the only thing in the video i noticed that was different from my experience. CHEERS!
Some high boost setups will compressor surge. Especially if you don't reach peak boost before you release the throttle. The BPVs in these setups are adjusted to stay closed during spool until that high boost target is reached. So when you release the throttle at partial boost in these setups you get "surge". This is the only time compressor surge is acceptable to me. I've been building and tuning engines/cars for over a decade.
the comments here kill me lmao all these people saying these guys dont know what theyre talking about just because you all sit on random forums and read articles, yeah the guy who has actually owned tons of high horsepower turbo cars is definentally less informed than some 12 year old behind his computer give me a break.
Not defending internet mechanics, but owning a powerful car (or cars) doesn't always imply knowledge, it just means someone has money. When shit breaks they'd just take it to some guy who sorts it out for them. Same goes for upgrades; "Here's my credit card, give me more power!" (Not saying this of Street FX Motorsport guys, but I do personally know people who have things like GTRs and haven't a clue about the technicalities behind them, they can reel off lists of numbers though like bore, stroke, whp, shp and torque without knowing shit about what they mean! - it's like they're playing a game of top trumps or something lol)
You trust the same people that made said turbos before BOV's were a thing? You do know that half of these companies popped up after the car craze that fast and the furious caused. Go to any company thats been dealing with modded cars from before that and they'll tell you they arent needed. Its a gimmick to sell you something you dont need. You do know that BOV's are relatively new. OF course a company that makes turbo's, BOV's and other things is going to tell you need a certain part so you'll buy the part. Take a look at all the older cars with turbos. NONE had BOV's. None of em. They all ran just fine. As a matter of fact a neighbor still has his old grand national with a turbo as old as I am that came with from the factory. No bov ever and the car still runs strong. There is no NEED for it. If you want one. Get one. But its not needed. If the car is surging under load its a tune/mechanical problem. Not the lack of a BOV.
squishypitbull this is the stupidest comment on here. They also didn't come with air bags or seatbelts at one point. Doesn't make it a better idea. There's a reason EVERY factory turbo these days comes with a blowoff/bypass/recirculation valve. "My neighbor, friend, sister's brother" stories... Always fact based right? STFU.
To summarize - Compressor surge when on the throttle is terrible and can kill engines/turbos. "Flutterdumps" (no BOV with boost reversion out of the intake) when off throttle/throttle closed is slightly worse for the turbo bearings than running a BOV, and will slightly reduce boost response between gears. It does sound fuckin' mint tho hahaha
Yep, we mention this in the body as we didn't address it very well in the video.. However I would be interested to know exactly why this is any worse for the turbo than normal closed throttle surge..
I had always been told because it slows the compressor down quickly (not stops!) it can wear bearings out quicker. I have no researched data to back that up tho. Perhaps you could do a collab video with a turbo manufacturer or repairer in the future that covers such things?
Legotruck82 we plan to do that :) I just struggled to see why closed and open throttle surge would impact the turbo in differing ways, since they both subject the turbo components to the exact same conditions. It's a great question though :)
I think on boost flutter could be a little worse because it's pushing hard on the exhaust side at the same time as the intake side is slowing the compressor wheel down. A bit like being on the throttle while braking wears the pads and rotors more than if you were only braking. If you shut the throttle there is no exhaust gasses pushing on the exhaust side. But on boost surge would create opposing forces. But then again that would only try to twist the axle witch it could never do anyway. But considering the angle at witch the force comes on to the blades (pushing from the side) I don't really see how it could effect the wear of the turbo, because it would require the axle to move enough sideways to break through the protective oil film and hit the bearing surface. If there is any extra wear I don't think it would even be measurable.
If you're getting surge on boost its usually because you are not limiting low end boost, big turbos don't like running high pressure ratios with low flow . Which would be right in the middle of efficiency island of a small turbo. This why a lot of setups ran a small and big turbo, yes the small one can spool up quicker for the low end but it can also sustain more pressure at lower flow allowing more boost at low revs without surge occuring. The damage you can cause by surging is primarily to the thrust washers particularly on journal bearing turbos. When the shaft bashes back and forth. If you run oil good pressure and have tight tolerances the shaft can't move and pick up as much speed when it moves back and forth which is what is going to kill the turbo. I think smaller turbos are more susceptible to damage since they typically don't have the relive holes that you see on big turbos and smaller turbos in general are just cheaper and may not have the same safety margin as a big turbo might.
Compressor surge is the sound of the blades chopping through the air that is being forced back through and out of the intake side of the turbo. Not good for the components of the turbocharger but not going to immediately destroy anything either.
Im pretty sure its the air passing at very high velocity through the tight clearance between the circumference of the inducer (blade tips)... and the compressor housing. The same principle behind whistling with your mouth. I don't think the "chopping" has anything to do with it.
LMAO, This subject seemingly will never die! As a 25 year Veteran of the Melbourne Boost Car scene i've been absolutely gobsmacked by the vastly differing opinions by those in the know about something that in essence Is mechanical science. My real fascination is with the differences of opinion coming from the guys at the very top of their respective specialities ie: VL Turbo guys, Rotary Turbo Guys, the XR6 Turbo crew, and of course the GTR and Supra workshops. The mechanical science is simple! Its not "Good" for the turbo! but Its not going to kill it overnight either. But what's very interesting to me, is how much the boost car scene has evolved into various sub cultures! Way back in 1996-99 Era when the bright orange MAZTECH RX3 13B Turbo was running 9s (Unbelievably fast in 98) it was all about extracting as much power as possible, but in 2017 making power is piss easy if you have the money, so now other factors seem to be desired. I've had many serious conversations with certain "Younger" individuals that in all seriousness spend mega dollars in search of the "Perfect Sounding Flutter" NO BS!!! I recently asked a younger guy if he had a blow off valve installed somewhere in amongst that harmony of dosing, fluttering, external gating, devices? To my utter astonishment his reply was simply "Na bro, i'm not really into those sorts of noises yeah" ok now i feel old :(
Josh Brookes Cause they are uneducated. Street Fx doesn't know shit either. He is just a rich guy who can afford shit to break. He doesn't even work on his cars but workshops and educated staff do the work. So its simple really, surging the wave of boost back into the compressor is OBVIOUSLY DESTRUCTIVE and shouldn't do it, but the fanboys and 'oh the flutter is so siiq it makes me moist and gets all the bitches' roll in, then talking shit about properly done up & tuned car. There was this guy running his car N/A to Boosted without a tune and going around saying he is the top shit cause his car now makes tut tut noises. I wanna kms
Some of the best engine builders and tuners in Australia don't run blow of valves/bypass valves on the engines they build/tune, unless you consider them to be uneducated? StreetFX can afford to fix shit if it breaks but he also hasn't had to replace a turbo because of flutter.
DriftNick I dont know of these tuners. Any high hp making car I have seen has a blow off & set to not flutter. Kids make wanted flutter. Any racing car has correct blow off & waste gate set to not flutter either. So...
DriftNick You do what you want with your car, but when I build mine, I build it to perfection, and that excludes flutter cause I personally from all the knowledge I have, is bad. ( i think its bad)
People dont realise that a turbo technically stalls as air pressure drops around the blades when the throttle shuts and no blow of valve is there to allow all the built up air to escape before turbo. When the throttle shuts and all that pressure comes back through the turbo it causes the blades to loose grip of the air due to the low air pressure and making it spin at the same speed without actually making any boost. The turbo blades then eventually grip back onto the air when air pressure rises around the blades again. the sut sut sut noise is created by the turbo constantly loosing grip and grabbing in short matters of time.
You're talking absolute rubbish. The SOUND is created by high velocity air flowing back through the tight clearance between the inducer circumference (blade tips)... and the compressor housing. Same principle as whistling with your mouth.
always i have a "noncar-friend" on my urs4 and when it flutters and i say to my friends "squirrels escaping..." and my friends look me with weird look in his eyes like "wtf dude?" :D
Normally I don't like channels like this, but I'm surprised Street FX Motorsport TV. You do a decent job. Kudos. Unlike Motive DVD (Who even owns a DVD player anymore?)
Always thought compressor surge sounded like Curly from The Three Stooges. In other words...silly. "Come back here, you!" (runs away) "Woobwoobwoobwoobwoob!!!"
Zoidburge from futurama had a cummins 12 valve that made that sound of woobwoobwoobwoobwoob first time I heard it make the woobwoobwoob sound I named it zoidburge hahahahaha
Turbo surge can also be your tune! Two reasons are,too high of a boost level at too low of an rpm, and even if in high gear and high rpm, your throttle body percentage (amount open) is not at WOD so partially closed will add resistance to the turbo and cause higher boost levels but would be a “false” reading because the turbo’s flow is maxed out at the throttle body instead of the boost pressure being maxed out at the cylinder or behind the intake valve.
"All the cards flying through the air" is very much due to the BIG ASS fan in front of the car. If you look closely, the car shutters when going off throttle which causes the stack of cards to move enough for the fan to blow them away. I find it nearly impossible for the boost pressure to come out the inlet side of the turbo. At that point it would HAVE to make the compressor wheel turn backwards.
For all the ppl asking or assuming it damages the turbos components.., it’s both yes and no… the rotating impeller speed, it’s seals, the inner clearances, the bearings.., by numbers on paper and science yes it SHOULD hurt components BUT how many videos have you seen with ppl showing damaged turbos from surge?? None..
Nice vid, but you did sidestep the point that compressor surge when on throttle is bad, because you're trying to spool the turbo on the hotside but the compressor side cant push the air, so it puts the turbo under a lot of stress.
My 1.9 jtd turbodiesel did that sound when my VNT valve went bad. Didn't know such small turbo can do it. It was cool but the car was almost undrivable, and in the end I found it literally spit some oil into the MAF and air filter :)
The flutter is a result of how hard your blow off valve spring is. My BOV spring is is full hard, so I get flutter even at very low speeds. Its not harmful to the turbo at all at these low speeds, because as soon as I put my foot down and generate full bpoost there is enough pressure to open the BOV and release the air so this higher dose of air doesnt hurt the turbo.
Yeah same. I was confused with the flutter sound being bad cause my flutter comes from my bov letting air out in a flutter, I think it's supposed to simulate the compressor surge sound? Someone correct me if im wrong.
4:46 You don't think the vibration/stuttering/shock from the compressor surge attributed to the loosening of the compressor wheel nut? Gotta say I completely agree with almost everything you said. I really dislike the noise of surge so I always run plumbed BOVs. Each to their own :)
Yes, what you are saying is true-4.27, putting a little stress on turbine when flutter started. I would say the principle in water hydraulics- that if you try to swim against the stream it would put more stress on my body or joints. In real world, if you have the money then turbo sounds matters than turbo longevity.
Thanks for this valuable information! I was slightly worried about my turbo after my Diverter valve failed on a recent road trip resulting in compressor surge / Turbo Flutter. I ended up driving about 400 miles with this condition and I didn't really seem to have any boost lost. I was just worried about the stress it might of caused my turbo. Since this owner has been going DV/BOV less or whatever and intentionally causing the flutter I'm guessing the 400 miles I did like this before changing my DV valve to prevent Flutter didn't cause any harm. A different youtuber made it sound like it was pretty harmful on bearings hardware.
I have had my 180SX for 21yrs and I get some flutter and love it with my GFB dual BOV I have it plumbed back to the inlet of my turbo to help keep it spooling when I go full boost there's no flutter only low to mid throttle.
Route a boost gage to the compressor housing to see how much pressure it is seeing when the surging occurs? That noise could be interpreted as boost spike, maybe? Which would mean unnecessary stress to turbo internals. Still gonna send it though... (just my opinion)
as a owner of a car that has epic compressor surge here are a few tips. 1. it doesnt fuck your turbo 2. never blown a turbo due to flutter all my cars have been 20psi plus 3. more boost more noise
Depends the turbo dudes. With anti surge turbo you will not ever brake anything with flutter. Its not turning the turbo wheel backwards but the trapped air hits back the compressor wheel cause there's no elsewhere to go. So 2 things will go wrong brake the shaft if the shaft its not that strong or destroy the wheel wings on high amount of boost. I've seen both of them situation.
Turbochargers are fundamentally centrifugal pumps that are driven by a turbine. Most other centrifugal pumps can be stalled for days without ill effects.
if u have a nice turbo its not gonna hurt it that much but if u have an old turbo or china turbo just run a blow off valve it is cheap and still sounds cool and can extend the life of your turbo.
Surge did eventually kill the CT26 in my old Supra, it was an old ass turbo with wear on it though & the final straw was when I lost ignition at full throttle (Pushing about 14-15psi on a mostly stock 7M) and pretty much hot-stopped. The turbine sheared off the shaft, pretty obvious twisting action looking at the break point. Don't think it would've killed a mint turbo though, it was ready to die anyway since I bought the car & then I just turned the boost up till it popped...
I ran without a BOV on my Saab for a straight year. With the unreliable turbo. With 185k on it at the time. It's now at 197k and I have a BOV again, but it's still fine, lol. I'm not saying it's completely save and the smartest thing to do... but people blow it way out of proportion.
I have installed blow off valve spacer in my Fiesta ST 1.6 230 hp for the whooosh sounds and even though everything is installed correctly, somehow i get the turbo flutter upon releasing the throttle which shouldnt be the case. But i quite enjoy it, question is... is it safe for the stock small KP39 turbo? :D
i enjoyed the vid. one thing though...when you say you never ruined a turbo...except this one time the nut on the compressor unscrewed itself and the compressor shredded...
thank you. it's refreshing to hear sane people open their mouth and share this thing called knowledge rather that complete numb skulls who know sweet F A and sprout complete and utter rubbish to me. Another thing you might want to add to this argument is the detrimental effect caused by adding a BOV to car running an air flow meter as opposed to map sensor. Running a bov on some cars will without a doubt right royally f*@# them i.e some models of WRX for instance. On others it may not wreck them but fuel economy and general performance (or lack thereof) goes up the sh*t. Usually the same numb skulls who argue that bovs are necessary are the same idiots on forums asking diagnostic questions like "my car's running sluggish and fuel economy is out the window, does anyone know what things I should check for incase my engine's blown or something?" my responses is always a question does it have an aftermarket bov? if the answer is yes I instruct them to check for a brain 👍
It doesn't allways affect the performance or lag.. With a bov it dumps the air pressure in your intake and piping etc then your turbo needs to re pressurise it when you come back on the gas.. . No bov keeps the air pressure in the system, that's why lotta rally cars don't run a bov
The turbo that the nut came off and you claim wasn't caused by turbo flutter, are you so sure? Given that both the turbine wheels are connected through the shaft, when the inlet impeller slows down, it will be trying to go slower than the shaft and exhaust turbine which doesn't have a restriction of airflow slowing them down like on the inlet side when the throttle is closed. The inlet turbine wanting to go slower than the shaft will put pressure on the holding nut. And the pressure put on that holding nut will be in the direction to undo the nut. So not really surprised the nut eventually worked it's way off.
As we mentioned to another person who asked that question - the Supra in question that had that happen *did* have a blow off valve.. It was also an old-style bush type turbo though, so it was probably due for an upgrade anyway.
🤔BoV and BPV needed during high horsepower applications.... staring at Subaru's Type RA that they developed with prodrive.... that flew through goodwood with ease and no problems....
This is great information. So why wouldn't you put dual BOVs? One at the intake inlet where it typically is mounted and one near the FMIC like most of the Supra and GTR guys.
It sounds like nails on a chalkboard and is bad for the turbo bearings. A blow off valve sounds great and saves bearings, intercoolers, boost pipes and hose clamps.
What you're saying is almost 100% correct but the fact that you're saying that it is the turbo that stalls that's almost just as stupid as saying that it's the turbo that's spinning backwards, the flutter is simply boost that's returning so air that's returning and smashing against the blades of the turbo, a helicopter that's flying into the direction of the wind is also making a chopping sound and it's the same principle ;) anyways good video and good explanation :)
I'm sure this has been said, but I feel like you're going to have a significantly higher chance of winging the nut off the end of a compressor wheel, if your turbo is surging. other than that, I agree with everything you've said.
squishypitbull it's designed in such a way that, under normal operations to stay tightened, because of the reverse thread. The CHRA stalling isn't normal operations.
set the blow of valve where it should be and size it properly and all you will here a slight rush of air and turbo will not be rapidly slowing down and you wont have shaft nuts coming loose on your turbo. its not unavoidable. But it does sound cool. but whoosh sounds fast.
Yes there are many things that can go wrong Improper cool down Too high a level of boost And if there ever was a wastegate or bov failure gases that need to escape would gradually wear the mechanism over time
"I've never blown a turbo.. except where the compressor nut came undone" Ever considered that during compressor surge, the forces on the compressor tend to load that nut up and can cause it to come undone?
I appreciate the info thats not just on the surface, ive heard a few N54 (bmw copy of the 2jz) BMW e92 335i cars have this surge sound before but VERY VERY few have it, im willing to dump a bit of performance for that sound, how would I get it? It seems to be a mystery in the community for that engine at least, some say BOV but the only way I can see that is if the BOV has a super hard spring In it
My 1.8 vw jetta dose this surge sound ......I don't see any issue , not lack of turbo spool or anything ......my bov spring is tighter tho , but good enough when u go full spool it blows fully
i had a mitsubishi 2.0 engine NA that would make a farting sound between WOT shifts and everybody thought it was a turbo. All it had was a $1 ebay Apexi knockoff coffee can exhaust and no turbo but it sounded MAD
Loved the video, I know exactly where you guys were filming this ( cause I live nearby) & the traffic there is shocking. Wonder if this is similar to how a diesel flutters or dose. But they don't have a throttle body of any kind as they run rpm from the fuel pump, so what's the compressed air getting stopped by to come back towards the turbo? The valves just before the combustion chamber?
Cant remember what controlld how much boost your engine gets. Doesnt bov also decide how much psi your engine gets? So if you remove it then you could send upwards of 50psi amd send your pistons through the roof? Cant remember if thats what the bov does also amd where you cam control how much psi it gets in mega squirt
Do you know her Jeremy Clarkson says it’s not the speed that kills you. It’s the sudden stoppage well, when people say the turbo spinning backwards, they don’t mean it’s literally spinning the opposite direction. They mean that the impeller rpm is slowing down to the point where air is making it Slow down. The air Hass to go back through the the turbo and it’s generally not good
When people are saying it is the turbo spinning backwards they are not understanding what compressor stall is, they think it's actually the turbo stopping, turbo flutter does not actually slow the turbo down, the turbo is already slowing down because of reduced exhaust flow, turbo flutter or not does not change how it slows down.
@@DriftNick compressor surgeon turbo flutter is the same thing I don’t really want to go over this when you can UA-cam turbo flutter in compressor search and there’s a video with a man with an electronic turbo that shows you the most basic form. What flutter a.k.a. surge is it doesn’t reverse the turbo it slows it down with enough force to cause damage do you ever see a plane just break apart that’s because the air has so much pressure it can destroy things and I’m not going to sit here and argue when you can do your own research
@@oler777 I know the are in the same thing, I didn't say otherwise, as for it slowing down the turbo it does not do that, people have literally tested it with a turbo speed sensor, the rate at which the turbo slows down after lifting off the throttle is the same between running a blow off valve and running no valve. "plane just break apart that’s because the air has so much pressure it can destroy things" Not even close to the same thing. "do your own research" Clearly something you have not done.
I have a question, if the air is coming back out of the turbo will that affect the MAF sensor if it is set on the intake side of it. Just thought the car would be regerstring that it's still getting air coming in when it isnt.
depends if it's a ball bearing turbo and it would depend on boost and how you drive it some will die quicker but even with a bov you get some surge just face it turbos arnt built too live forever it's so cheap for a new centre so do what you like
Since there is too many wannabe auto engineers on here I'm citing HTT/Garrett as a reference rather than grabbing words out of thin air; "Surge is the left hand boundary of the compressor map. Operation to the left of this line represents a region of flow instability. This region is characterized by mild flutter to wildly fluctuating boost and “barking” from the compressor. Continued operation within this region can lead to premature turbo failure due to heavy thrust loading. " Also feel free also to read up on ported shroud, there's a reason it's there (hint; moving surge line to the left to keep the turbo within OPERATING CONDITIONS)
"when people say it's the turbo spinning backwards, got rocks in their heads"
LOLOL I almost died that made my day
Stewzy their brains are spining backwards.
Must be the French
Yea like you.
Please show me a turbo spinning backwards when its surging off throttle?
Hakasauars jag rosyzafg
I rebuild turbos for a living, and what they're saying is pretty much correct. The thing is though, certain turbos can take lots of surge, and others cant. Turbos like Holset's, Garrett GT37R's, GT40R's, or larger with beefy thrust bearings can take a lot of surge out of the box. Turbos such as TD05/TD06's, Borg Warner S200/S300/S400's, K24/K26's, Garrett T3/T4's etc can take surge as well as long as they have an upgraded thrust bearing. That's the one part of the turbo under stress when surging, the thrust bearing. On a turbo with a not enough thrust bearing journal area, the thrust bearing wears out quickly (because it is overloaded with thrust load and the oil film is squeezed away) and then you get loads of in and out shaft play. Then one day the compressor wheel tears itself apart by hitting the compressor housing.
And another thing, turbo compressor nuts are threaded in reverse from the turbos direction of rotation, so they don't back off, they will only get tighter. Basically any OEM turbo is not designed to take the extreme thrust load from surging. Small frame steel ball bearing turbos will develop excessive shaft play from surge as well, ceramic ball bearing ones are generally okay.
Bottom line is most properly built aftermarket turbos with 360 degree thrust bearings, or just plain ceramic ball bearings can take the load of compressor surge. If you surge your OEM turbo it will probably last a good 6 months to a year of daily driving, less if you're running more than stock boost.
House of Boost I have a stock 2015 evo and I was thinking of buying an aftermarket bov like Gfb.... any tip would be gladly appreciated.
go ahead, i dont have any tips there other than i personally like the tial q bov for its sound. obviously get a blockoff plate for the diverter valve and have the car tuned to a bov
House of Boost probably the best thing i read out of this whole shit talking comments about uneducated big babies lol.
House of Boost that's the best shit i read ever
Thanks for knowing how to explain, we need people like you in this comments...
It's the Aussie way. We love the turbo flutter. It's 100% about the sound! Does its damage the turbo? My opinion as a mechanic for 15 years and owned many turbo is no
Will it do it with a stock turbo?
@@carsandcoldbrew6489 no
@UCG3ZTLNnemoeCICJ1vOf1GQ yes it will 😂 you’re a fucking loonie mate
Does the GTX2867R flutter tho?
@@ronyhyper why not?
Dude this eased my mind quite a bit. Thank you lol
The flutter (sututututu) noises are caused by the throttle snapping closed and all the air thats already heading to the intake gets stoped and fills up the intake pipes all the way back to the turbo, and forcing it way through the compressor fan while its still spining at its ridiculous rpm, forcing the compressor fan to cut through the air, thus making the flutter noise
That's exactly what we said ;)
Street FX Motorsport TV verbatim.
Thank you. Did a much better job explaining
You can see how it can effect the inadequate thrust bearing especially at high boost i.e 2 opposing forces
so what do you guys think, with flutter caused by throttle closer as Jimmy points out above, would that hurt the compressor or not? If the BOV/BPC was set up correctly, I thought it should vent all that excess pressure between compressor and closed throttle plate, and there would be little to no air having to escape through the spinning compressor wheel, and hence no flutter?!
Thank you for clarifying, now i can show people this video instead of trying to explain why they're wrong. The only thing i noticed is that with no bov on my mr2 i actually had a MORE RESPONSIVE turbo while changing gears...when i ran a bov there was MORE LAG while changing gears at WOT. Thats the only thing in the video i noticed that was different from my experience. CHEERS!
Some high boost setups will compressor surge. Especially if you don't reach peak boost before you release the throttle. The BPVs in these setups are adjusted to stay closed during spool until that high boost target is reached. So when you release the throttle at partial boost in these setups you get "surge". This is the only time compressor surge is acceptable to me. I've been building and tuning engines/cars for over a decade.
Why is it whenever you find a straightforward and knowledgeable videos it's an Aussie channel?!
Love your work guys
Xr6t should be dosing soon ♥️
Papadakis racing is a great channel if your into how everything works!
the comments here kill me lmao all these people saying these guys dont know what theyre talking about just because you all sit on random forums and read articles, yeah the guy who has actually owned tons of high horsepower turbo cars is definentally less informed than some 12 year old behind his computer give me a break.
ahaha we deal with it daily :) internet mechanics :D
Not defending internet mechanics, but owning a powerful car (or cars) doesn't always imply knowledge, it just means someone has money. When shit breaks they'd just take it to some guy who sorts it out for them. Same goes for upgrades; "Here's my credit card, give me more power!" (Not saying this of Street FX Motorsport guys, but I do personally know people who have things like GTRs and haven't a clue about the technicalities behind them, they can reel off lists of numbers though like bore, stroke, whp, shp and torque without knowing shit about what they mean! - it's like they're playing a game of top trumps or something lol)
UTxBEAST96 I trust the words of folks who engineer and design turbos and BOVs. Not dipshits like this.
You trust the same people that made said turbos before BOV's were a thing?
You do know that half of these companies popped up after the car craze that fast and the furious caused.
Go to any company thats been dealing with modded cars from before that and they'll tell you they arent needed. Its a gimmick to sell you something you dont need.
You do know that BOV's are relatively new. OF course a company that makes turbo's, BOV's and other things is going to tell you need a certain part so you'll buy the part.
Take a look at all the older cars with turbos. NONE had BOV's. None of em. They all ran just fine. As a matter of fact a neighbor still has his old grand national with a turbo as old as I am that came with from the factory. No bov ever and the car still runs strong.
There is no NEED for it. If you want one. Get one. But its not needed.
If the car is surging under load its a tune/mechanical problem. Not the lack of a BOV.
squishypitbull this is the stupidest comment on here. They also didn't come with air bags or seatbelts at one point. Doesn't make it a better idea. There's a reason EVERY factory turbo these days comes with a blowoff/bypass/recirculation valve. "My neighbor, friend, sister's brother" stories... Always fact based right? STFU.
I can’t stop looking at that perfect dashboard lol a r32 with no dash bubble
To summarize - Compressor surge when on the throttle is terrible and can kill engines/turbos. "Flutterdumps" (no BOV with boost reversion out of the intake) when off throttle/throttle closed is slightly worse for the turbo bearings than running a BOV, and will slightly reduce boost response between gears. It does sound fuckin' mint tho hahaha
Yep, we mention this in the body as we didn't address it very well in the video.. However I would be interested to know exactly why this is any worse for the turbo than normal closed throttle surge..
I had always been told because it slows the compressor down quickly (not stops!) it can wear bearings out quicker. I have no researched data to back that up tho. Perhaps you could do a collab video with a turbo manufacturer or repairer in the future that covers such things?
Legotruck82 we plan to do that :) I just struggled to see why closed and open throttle surge would impact the turbo in differing ways, since they both subject the turbo components to the exact same conditions. It's a great question though :)
I think on boost flutter could be a little worse because it's pushing hard on the exhaust side at the same time as the intake side is slowing the compressor wheel down. A bit like being on the throttle while braking wears the pads and rotors more than if you were only braking. If you shut the throttle there is no exhaust gasses pushing on the exhaust side. But on boost surge would create opposing forces. But then again that would only try to twist the axle witch it could never do anyway. But considering the angle at witch the force comes on to the blades (pushing from the side) I don't really see how it could effect the wear of the turbo, because it would require the axle to move enough sideways to break through the protective oil film and hit the bearing surface. If there is any extra wear I don't think it would even be measurable.
good point, I'd never thought about it like that.
If you're getting surge on boost its usually because you are not limiting low end boost, big turbos don't like running high pressure ratios with low flow . Which would be right in the middle of efficiency island of a small turbo. This why a lot of setups ran a small and big turbo, yes the small one can spool up quicker for the low end but it can also sustain more pressure at lower flow allowing more boost at low revs without surge occuring.
The damage you can cause by surging is primarily to the thrust washers particularly on journal bearing turbos. When the shaft bashes back and forth.
If you run oil good pressure and have tight tolerances the shaft can't move and pick up as much speed when it moves back and forth which is what is going to kill the turbo. I think smaller turbos are more susceptible to damage since they typically don't have the relive holes that you see on big turbos and smaller turbos in general are just cheaper and may not have the same safety margin as a big turbo might.
Compressor surge is the sound of the blades chopping through the air that is being forced back through and out of the intake side of the turbo. Not good for the components of the turbocharger but not going to immediately destroy anything either.
Chopping through the air Hahahaha
Sancho it is ;) think about a helicopter flying into the direction of the wind ;) same principle
Who the fuck cares. Its also good to have a catch can for your motor. How many cars have those.....
@@AlphaFlight I doooo.
Im pretty sure its the air passing at very high velocity through the tight clearance between the circumference of the inducer (blade tips)... and the compressor housing. The same principle behind whistling with your mouth. I don't think the "chopping" has anything to do with it.
LMAO, This subject seemingly will never die! As a 25 year Veteran of the Melbourne Boost Car scene i've been absolutely gobsmacked by the vastly differing opinions by those in the know about something that in essence Is mechanical science. My real fascination is with the differences of opinion coming from the guys at the very top of their respective specialities ie: VL Turbo guys, Rotary Turbo Guys, the XR6 Turbo crew, and of course the GTR and Supra workshops. The mechanical science is simple!
Its not "Good" for the turbo! but Its not going to kill it overnight either. But what's very interesting to me, is how much the boost car scene has evolved into various sub cultures! Way back in 1996-99 Era when the bright orange MAZTECH RX3 13B Turbo was running 9s (Unbelievably fast in 98) it was all about extracting as much power as possible, but in 2017 making power is piss easy if you have the money, so now other factors seem to be desired. I've had many serious conversations with certain "Younger" individuals that in all seriousness spend mega dollars in search of the "Perfect Sounding Flutter" NO BS!!! I recently asked a younger guy if he had a blow off valve installed somewhere in amongst that harmony of dosing, fluttering, external gating, devices? To my utter astonishment his reply was simply "Na bro, i'm not really into those sorts of noises yeah" ok now i feel old :(
Josh Brookes Cause they are uneducated. Street Fx doesn't know shit either. He is just a rich guy who can afford shit to break. He doesn't even work on his cars but workshops and educated staff do the work. So its simple really, surging the wave of boost back into the compressor is OBVIOUSLY DESTRUCTIVE and shouldn't do it, but the fanboys and 'oh the flutter is so siiq it makes me moist and gets all the bitches' roll in, then talking shit about properly done up & tuned car. There was this guy running his car N/A to Boosted without a tune and going around saying he is the top shit cause his car now makes tut tut noises. I wanna kms
Some of the best engine builders and tuners in Australia don't run blow of valves/bypass valves on the engines they build/tune, unless you consider them to be uneducated? StreetFX can afford to fix shit if it breaks but he also hasn't had to replace a turbo because of flutter.
DriftNick I dont know of these tuners. Any high hp making car I have seen has a blow off & set to not flutter. Kids make wanted flutter. Any racing car has correct blow off & waste gate set to not flutter either. So...
DriftNick You do what you want with your car, but when I build mine, I build it to perfection, and that excludes flutter cause I personally from all the knowledge I have, is bad. ( i think its bad)
Search "50psi boost 1200+hp Nissan RB30" on youtube, more videos on that channel of high hp cars not running a blow off valve/bypass valve.
People dont realise that a turbo technically stalls as air pressure drops around the blades when the throttle shuts and no blow of valve is there to allow all the built up air to escape before turbo. When the throttle shuts and all that pressure comes back through the turbo it causes the blades to loose grip of the air due to the low air pressure and making it spin at the same speed without actually making any boost. The turbo blades then eventually grip back onto the air when air pressure rises around the blades again. the sut sut sut noise is created by the turbo constantly loosing grip and grabbing in short matters of time.
You're talking absolute rubbish. The SOUND is created by high velocity air flowing back through the tight clearance between the inducer circumference (blade tips)... and the compressor housing. Same principle as whistling with your mouth.
THIS CAR IS LAUGHING SO HARD AT YOUR DRIVING SKILLS!!
Great effect tho. Great Video :D
Mark your an absolute legend I love all your content and your tiktok keep it up boss
always i have a "noncar-friend" on my urs4 and when it flutters and i say to my friends "squirrels escaping..." and my friends look me with weird look in his eyes like "wtf dude?" :D
Normally I don't like channels like this, but I'm surprised Street FX Motorsport TV. You do a decent job. Kudos. Unlike Motive DVD (Who even owns a DVD player anymore?)
Always thought compressor surge sounded like Curly from The Three Stooges. In other words...silly.
"Come back here, you!"
(runs away) "Woobwoobwoobwoobwoob!!!"
Nuk,Nuk,Nuk .....
Zoidburge from futurama had a cummins 12 valve that made that sound of woobwoobwoobwoobwoob first time I heard it make the woobwoobwoob sound I named it zoidburge hahahahaha
Here come all the 12 year olds saying "I have a gtr and my dad says it's the sound of the blow off valve"
Turbo surge can also be your tune! Two reasons are,too high of a boost level at too low of an rpm, and even if in high gear and high rpm, your throttle body percentage (amount open) is not at WOD so partially closed will add resistance to the turbo and cause higher boost levels but would be a “false” reading because the turbo’s flow is maxed out at the throttle body instead of the boost pressure being maxed out at the cylinder or behind the intake valve.
"All the cards flying through the air" is very much due to the BIG ASS fan in front of the car. If you look closely, the car shutters when going off throttle which causes the stack of cards to move enough for the fan to blow them away. I find it nearly impossible for the boost pressure to come out the inlet side of the turbo. At that point it would HAVE to make the compressor wheel turn backwards.
It doesn't make it turn backwards, the air does come out the inlet side. It physically has nowhere else to go.
Turbos spin at 100,000rpm, it cannot suddenly stall and go backwards.
I was always told if it does the flutter while on the gas it is bad, if it is happening when you let off ONLY then its okay.
For all the ppl asking or assuming it damages the turbos components.., it’s both yes and no… the rotating impeller speed, it’s seals, the inner clearances, the bearings.., by numbers on paper and science yes it SHOULD hurt components BUT how many videos have you seen with ppl showing damaged turbos from surge?? None..
Stutututu...Great! Love this sounds,greetings from KK Sabah,Malaysia🇲🇾👊👍
Nice vid, but you did sidestep the point that compressor surge when on throttle is bad, because you're trying to spool the turbo on the hotside but the compressor side cant push the air, so it puts the turbo under a lot of stress.
My 1.9 jtd turbodiesel did that sound when my VNT valve went bad. Didn't know such small turbo can do it. It was cool but the car was almost undrivable, and in the end I found it literally spit some oil into the MAF and air filter :)
The flutter is a result of how hard your blow off valve spring is. My BOV spring is is full hard, so I get flutter even at very low speeds. Its not harmful to the turbo at all at these low speeds, because as soon as I put my foot down and generate full bpoost there is enough pressure to open the BOV and release the air so this higher dose of air doesnt hurt the turbo.
Yeah same. I was confused with the flutter sound being bad cause my flutter comes from my bov letting air out in a flutter, I think it's supposed to simulate the compressor surge sound? Someone correct me if im wrong.
4:46 You don't think the vibration/stuttering/shock from the compressor surge attributed to the loosening of the compressor wheel nut? Gotta say I completely agree with almost everything you said. I really dislike the noise of surge so I always run plumbed BOVs. Each to their own :)
Just saw your previous reply stating the car in question did have a BOV and a very badly worn turbo.
Yes, what you are saying is true-4.27, putting a little stress on turbine when flutter started. I would say the principle in water hydraulics- that if you try to swim against the stream it would put more stress on my body or joints. In real world, if you have the money then turbo sounds matters than turbo longevity.
Great easy to understand explanation 👍
Thanks for this valuable information! I was slightly worried about my turbo after my Diverter valve failed on a recent road trip resulting in compressor surge / Turbo Flutter. I ended up driving about 400 miles with this condition and I didn't really seem to have any boost lost. I was just worried about the stress it might of caused my turbo. Since this owner has been going DV/BOV less or whatever and intentionally causing the flutter I'm guessing the 400 miles I did like this before changing my DV valve to prevent Flutter didn't cause any harm. A different youtuber made it sound like it was pretty harmful on bearings hardware.
I have had my 180SX for 21yrs and I get some flutter and love it with my GFB dual BOV I have it plumbed back to the inlet of my turbo to help keep it spooling when I go full boost there's no flutter only low to mid throttle.
Route a boost gage to the compressor housing to see how much pressure it is seeing when the surging occurs? That noise could be interpreted as boost spike, maybe? Which would mean unnecessary stress to turbo internals.
Still gonna send it though... (just my opinion)
Compressor stall is something inginerds work VERY hard to prevent in most scenarios. In severe cases it can take chunks out of compressor blades.
A mate of mine has the Mk7 GTi we noticed this is only during econo mode....... When in sport it runs like a beauty
as a owner of a car that has epic compressor surge here are a few tips.
1. it doesnt fuck your turbo
2. never blown a turbo due to flutter all my cars have been 20psi plus
3. more boost more noise
Depends the turbo dudes. With anti surge turbo you will not ever brake anything with flutter. Its not turning the turbo wheel backwards but the trapped air hits back the compressor wheel cause there's no elsewhere to go. So 2 things will go wrong brake the shaft if the shaft its not that strong or destroy the wheel wings on high amount of boost. I've seen both of them situation.
LOL! This sound is very funny, I prefer it with the priority valve open.
4:50 I guess you could say his turbo.... hit the fan?
Thanks for the very informative video!
Thanks man to tell ppl whats goin on!! I have the same sound with my gr28rs60 on my s13 ca18det and i f. love it!
My r31 Skyline doses been like that for 4 years turb is still strong as not 1 issue
This is reassuring, thanks
Are you able to get the pigeon/flutter noise on any car? Or does it matter with engine.
As long as you have turbo
Very good information... love the car
the first flutter was devious
I was driving with my father on the highway when the intercooler blew up.
Did you hit a pigeon or something
@@nolesy34 no, the turbo just suddenly supplied less compression, but we still made it home.
Turbo Flutter, clean Turbo set up , Clean Decals , XBOX Logo on car .... SICK Ass car in my book lol
To me best argument is when those people/kids are argue are that dump-valve sound, wastegate, compressor surge, flutters etc, etc... :D :D :D
Turbochargers are fundamentally centrifugal pumps that are driven by a turbine. Most other centrifugal pumps can be stalled for days without ill effects.
Those centrifugal pumps spin at 120,000 rpm?
if u have a nice turbo its not gonna hurt it that much but if u have an old turbo or china turbo just run a blow off valve it is cheap and still sounds cool and can extend the life of your turbo.
A lot of reputable tuners say it effects your thrust bearing.
Surge did eventually kill the CT26 in my old Supra, it was an old ass turbo with wear on it though & the final straw was when I lost ignition at full throttle (Pushing about 14-15psi on a mostly stock 7M) and pretty much hot-stopped. The turbine sheared off the shaft, pretty obvious twisting action looking at the break point. Don't think it would've killed a mint turbo though, it was ready to die anyway since I bought the car & then I just turned the boost up till it popped...
How did losing ignition kill it?
It was under boost at high revs, auto gearbox so I couldn't keep the engine spinning hence lost oil pressure and hot stopped the turbo. Shaft sagged.
@@danmackintosh6325 So it lost oil pressure but that didn't kill it, surge killed it???
heck yea this is one of the bes flutter sounds!! ,, sounds amazing !! 😀👍😀👍😀👍
The surge while on throttle seems sketchy lol. And seems like the car is kind of cutting out every time. Down size the turbo I guess
I ran without a BOV on my Saab for a straight year. With the unreliable turbo. With 185k on it at the time. It's now at 197k and I have a BOV again, but it's still fine, lol. I'm not saying it's completely save and the smartest thing to do... but people blow it way out of proportion.
Why take the chance?
Perfect for cleaning out the KN filters
I have installed blow off valve spacer in my Fiesta ST 1.6 230 hp for the whooosh sounds and even though everything is installed correctly, somehow i get the turbo flutter upon releasing the throttle which shouldnt be the case. But i quite enjoy it, question is... is it safe for the stock small KP39 turbo? :D
i enjoyed the vid. one thing though...when you say you never ruined a turbo...except this one time the nut on the compressor unscrewed itself and the compressor shredded...
The car that killed the turbo actually had a BOV.
Thanks for the knowledge! You got a scriber
I love the flutter sounds
When I cranked up the boost on my $100 Pontiac Sunbird without a BOV the Turbo was done in a few months....
"When I cranked up the boost" That is the real problem.
I use a boost valve , because use a bushing turbo, and I can't afford to loose any spooling.
thank you. it's refreshing to hear sane people open their mouth and share this thing called knowledge rather that complete numb skulls who know sweet F A and sprout complete and utter rubbish to me. Another thing you might want to add to this argument is the detrimental effect caused by adding a BOV to car running an air flow meter as opposed to map sensor. Running a bov on some cars will without a doubt right royally f*@# them i.e some models of WRX for instance. On others it may not wreck them but fuel economy and general performance (or lack thereof) goes up the sh*t. Usually the same numb skulls who argue that bovs are necessary are the same idiots on forums asking diagnostic questions like "my car's running sluggish and fuel economy is out the window, does anyone know what things I should check for incase my engine's blown or something?"
my responses is always a question does it have an aftermarket bov? if the answer is yes I instruct them to check for a brain 👍
I like a loud whistling turbo and a violent blow off valve :)
It doesn't allways affect the performance or lag.. With a bov it dumps the air pressure in your intake and piping etc then your turbo needs to re pressurise it when you come back on the gas.. . No bov keeps the air pressure in the system, that's why lotta rally cars don't run a bov
You just contradicted yourself .... And your are WRONG ...
@@ACommenterOnUA-cam explain
@@strider5119 what did you not understand ?
The turbo that the nut came off and you claim wasn't caused by turbo flutter, are you so sure? Given that both the turbine wheels are connected through the shaft, when the inlet impeller slows down, it will be trying to go slower than the shaft and exhaust turbine which doesn't have a restriction of airflow slowing them down like on the inlet side when the throttle is closed. The inlet turbine wanting to go slower than the shaft will put pressure on the holding nut. And the pressure put on that holding nut will be in the direction to undo the nut. So not really surprised the nut eventually worked it's way off.
As we mentioned to another person who asked that question - the Supra in question that had that happen *did* have a blow off valve.. It was also an old-style bush type turbo though, so it was probably due for an upgrade anyway.
🤔BoV and BPV needed during high horsepower applications.... staring at Subaru's Type RA that they developed with prodrive.... that flew through goodwood with ease and no problems....
This is great information. So why wouldn't you put dual BOVs? One at the intake inlet where it typically is mounted and one near the FMIC like most of the Supra and GTR guys.
Never. Never; blown a turbo......except for that one turbo that i blew. 😂😂😂
It sounds like nails on a chalkboard and is bad for the turbo bearings. A blow off valve sounds great and saves bearings, intercoolers, boost pipes and hose clamps.
Well it's a good thing running no blow off valve doesn't damage any of those things.
@@DriftNick just running and time damages them. Unnecessary boost spikes increase the wear on all of them.
What you're saying is almost 100% correct but the fact that you're saying that it is the turbo that stalls that's almost just as stupid as saying that it's the turbo that's spinning backwards, the flutter is simply boost that's returning so air that's returning and smashing against the blades of the turbo, a helicopter that's flying into the direction of the wind is also making a chopping sound and it's the same principle ;) anyways good video and good explanation :)
I'm sure this has been said, but I feel like you're going to have a significantly higher chance of winging the nut off the end of a compressor wheel, if your turbo is surging. other than that, I agree with everything you've said.
The nut will only tighten. Its designed that way.
squishypitbull it's designed in such a way that, under normal operations to stay tightened, because of the reverse thread. The CHRA stalling isn't normal operations.
Hey guys. Y’all explained this great... so if I want this flutter, should I just delete my blow off valve?
set the blow of valve where it should be and size it properly and all you will here a slight rush of air and turbo will not be rapidly slowing down and you wont have shaft nuts coming loose on your turbo. its not unavoidable.
But it does sound cool. but whoosh sounds fast.
Why do some UA-camrs says it damages it over time
Yes there are many things that can go wrong
Improper cool down
Too high a level of boost
And if there ever was a wastegate or bov failure gases that need to escape would gradually wear the mechanism over time
Because they have zero experience not running a blow off valve and have no idea what they are talking about.
"I've never blown a turbo.. except where the compressor nut came undone"
Ever considered that during compressor surge, the forces on the compressor tend to load that nut up and can cause it to come undone?
The supra that happened on had a blow off valve. Also the nuts on turbos are designed to tighten under those conditions, not loosen.
Yes - fair point - you are right, the nuts are usually threaded in the opposite direction to compressor rotation as you said.
Fail
But for ceramic turbo better to have bov to reduce the stress by turbo surging.
I appreciate the info thats not just on the surface, ive heard a few N54 (bmw copy of the 2jz) BMW e92 335i cars have this surge sound before but VERY VERY few have it, im willing to dump a bit of performance for that sound, how would I get it? It seems to be a mystery in the community for that engine at least, some say BOV but the only way I can see that is if the BOV has a super hard spring In it
Don't run a blow off valve and have a metal intake pipe going into the turbo, it will flutter.
My twin ball flutters like crazy, Even granny shifting at 2k around town.
My 1.8 vw jetta dose this surge sound ......I don't see any issue , not lack of turbo spool or anything ......my bov spring is tighter tho , but good enough when u go full spool it blows fully
I'm just here for the sssstu tu tu tu..... 😆
i had a mitsubishi 2.0 engine NA that would make a farting sound between WOT shifts and everybody thought it was a turbo. All it had was a $1 ebay Apexi knockoff coffee can exhaust and no turbo but it sounded MAD
Loved the video, I know exactly where you guys were filming this ( cause I live nearby) & the traffic there is shocking. Wonder if this is similar to how a diesel flutters or dose. But they don't have a throttle body of any kind as they run rpm from the fuel pump, so what's the compressed air getting stopped by to come back towards the turbo? The valves just before the combustion chamber?
You do know about clock wise running engine when you engage reverse gear..the crank will go anti-clock wise..only in front engine cars😉😉
Umm.. riiiigght...
The bigger question is which end of the engine do you look at when you decide whether it's running clockwise or anti-clockwise?
Its closed throttle compressor surge not open. If you hear the surge when throttle plates open something's wrong
so nobody is going to talk about the RB at 0:07 sounding like a diesel? What is it? lifter noise?
Cant remember what controlld how much boost your engine gets. Doesnt bov also decide how much psi your engine gets? So if you remove it then you could send upwards of 50psi amd send your pistons through the roof? Cant remember if thats what the bov does also amd where you cam control how much psi it gets in mega squirt
Do you know her Jeremy Clarkson says it’s not the speed that kills you. It’s the sudden stoppage well, when people say the turbo spinning backwards, they don’t mean it’s literally spinning the opposite direction. They mean that the impeller rpm is slowing down to the point where air is making it Slow down. The air Hass to go back through the the turbo and it’s generally not good
When people are saying it is the turbo spinning backwards they are not understanding what compressor stall is, they think it's actually the turbo stopping, turbo flutter does not actually slow the turbo down, the turbo is already slowing down because of reduced exhaust flow, turbo flutter or not does not change how it slows down.
@@DriftNick compressor surgeon turbo flutter is the same thing I don’t really want to go over this when you can UA-cam turbo flutter in compressor search and there’s a video with a man with an electronic turbo that shows you the most basic form. What flutter a.k.a. surge is it doesn’t reverse the turbo it slows it down with enough force to cause damage do you ever see a plane just break apart that’s because the air has so much pressure it can destroy things and I’m not going to sit here and argue when you can do your own research
@@oler777 I know the are in the same thing, I didn't say otherwise, as for it slowing down the turbo it does not do that, people have literally tested it with a turbo speed sensor, the rate at which the turbo slows down after lifting off the throttle is the same between running a blow off valve and running no valve.
"plane just break apart that’s because the air has so much pressure it can destroy things"
Not even close to the same thing.
"do your own research"
Clearly something you have not done.
Is that car allowed on the street because it has a aftermarket steering wheel and there are legal on Australian roads
I have open throttle compressor surge but its much less prominent more like a light flutter... i have heard its super bad for the car
It doesnt damage the turbo, but you loose performances compared to a by-pass valve
I have a question, if the air is coming back out of the turbo will that affect the MAF sensor if it is set on the intake side of it. Just thought the car would be regerstring that it's still getting air coming in when it isnt.
burger14uk yes. Sometimes mine will stall if I do a pull and put it in neutral fast. It will over fuel and cut off
I heard open throttle CS is a bad thing, but closed throttle isn't that big of a deal.
Thoughts?
the nut backed off from stopping and starting the turbo. did you have anti lag too? stop start and the nut backs off.
Good Work On EXPLAINING This...As FOR ME WITH A HIGH HP deisel there is no throttle body so I've yet to figure out how deisel make the same Sound
Not sure how it works without a throttle plate, but maybe the intake valves works as a throttle plate?
Whoah didn't realize this was 3 years old lol
depends if it's a ball bearing turbo and it would depend on boost and how you drive it some will die quicker but even with a bov you get some surge just face it turbos arnt built too live forever it's so cheap for a new centre so do what you like
Since there is too many wannabe auto engineers on here I'm citing HTT/Garrett as a reference rather than grabbing words out of thin air;
"Surge is the left hand boundary of the compressor map. Operation to the left of this line represents a region of flow instability. This region is characterized by mild flutter to wildly fluctuating boost and “barking” from the compressor. Continued operation within this region can lead to premature turbo failure due to heavy thrust loading. "
Also feel free also to read up on ported shroud, there's a reason it's there (hint; moving surge line to the left to keep the turbo within OPERATING CONDITIONS)
Great explanation tnx ✌😎👌