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How to make the turbo flutter? (also, is it bad?)

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30K views 20 replies 13 participants last post by  TT Tom TT  
#1 ·
Hello, I saw a couple of 1.8T engines which had that turbo fluttering sound and i really liked it. I was wondering how I could make my 180hp AUQ to do that stutututu noise...but I would also like to know if it damages the turbo (some say it's okay, others say that it could possibly snap the turbo shaft). I have already tried (just for testing) to disconnect the small vacuum hose from the DV but nothing happened...
 
#3 ·
Hoggy said:
Hi, You require a blow off valve, rather than Divert/Recirc valve, but a blow off valve will cause induction probs, fault codes & may be limp mode so not suitable for the 1.8T engine.
Fit a cone filter or a panel filter with Wak Box mod if you want to hear some induction noise.
Hoggy. :D
.....and remove the rear bonnet seal and the noise will be so great you can start weight saving by dumping off the ICE, as you won't be able to hear it! :lol:

VT
 
#4 ·
Just disconnecting the small vac hose will lead to constant recirculation during boost which will make your turbo work it's balls off to try and make boost. If you really want the fluttering noise you want to remove the dv and blank both ports off and blank the vac hose off.

(Here we go again lol)
 
#9 ·
I had a Leon Cupra which was mapped @244bhp with a forge dv and abd intake and that thing used to flutter like crazy, it had other bits and pieces also but was a while ago now (AUG or AGU engine, Ko3s turbo)

No ill effects, not while I had it anyways!
 
#11 ·
Put a c clamp or welding clamp on the hose from the charge pipe to the DV so it cant circulate. Enjoy the turbo flutter on throttle lift off but if you want your turbo bearings to live a little longer keep the original setup as Audi intended.
 
#12 ·
Hoggy said:
Hi, You require a blow off valve, rather than Divert/Recirc valve, but a blow off valve will cause induction probs, fault codes & may be limp mode so not suitable for the 1.8T engine.
Fit a cone filter or a panel filter with Wak Box mod if you want to hear some induction noise.
Hoggy. :D
There are mafless tunes all over for the 1.8t. Saying that mafless is not suitable for a 1.8t is kinda not true, it just requires a different fueling logic in the mapping that is not relying on the maf sensor. Bigger turbos for example exceed the flow limit of the vag MAF sensors (maxed out voltage), so in order to tune fueling past that maf sensor limit a Mafless tune is required.

BTW, that model is already written in the stock ECU (that's what happen when you unplug the maf). The associated maps are just richer for protection and it triggers a CEL. Writing off the CEL protocol and re-tuning the fuel map is all that's needed. I don't run a MAF or TIP on my car, and have a pair of dump valves -- car still runs flawlessly with both stock ECU and aftermarket standalone ECU.
 
#13 ·
Oranoco said:
My old Fiesta RS Turbo used to chatter like mad. Being MAP sensor based there was no fueling issues and the Garret T3 was pretty barn door with it's engineering so no ill effects.

That chatter is bad long term because it happens at full load when the charge system is pressurized. At full load it should bypass (if there is a compressor bypass) -- but it's fine if it flutters at low-load and part-throttle because there is no pressure in the system to create any reversal or damage.

Here is what my car sounds like with twin dump valves. Flutters at part throttle (minimal pressure in the system) and fully bypasses at full load (when excessive pressure waves can revert back to the compressor blades).
 
#14 ·
Madmax199 said:
Oranoco said:
My old Fiesta RS Turbo used to chatter like mad. Being MAP sensor based there was no fueling issues and the Garret T3 was pretty barn door with it's engineering so no ill effects.

That chatter is bad long term because it happens at full load when the charge system is pressurized. At full load it should bypass (if there is a compressor bypass) -- but it's fine if it flutters at low-load and part-throttle because there is no pressure in the system to create any reversal or damage.

Here is what my car sounds like with twin dump valves. Flutters at part throttle (minimal pressure in the system) and fully bypasses at full load (when excessive pressure waves can revert back to the compressor blades).
Not true on these cars and turbos until you exceed 30psi. I've run 2 of these hybrid T3's at 18psi and 25psi respectively and my brother ran another at 22psi. It's widely accepted practice in Ford tuning circles.
 
#15 ·
GARAGE HERMIT said:
Oranoco said:
My old Fiesta RS Turbo used to chatter like mad. Being MAP sensor based there was no fueling issues and the Garret T3 was pretty barn door with it's engineering so no ill effects.

that noise all the time would get right on my wick, no thank's, but each to their own,
It was driven deliberately to maximise the noise for the clip and it was 1 of my weekend toys not a daily so no issue.
 
#16 ·
Oranoco said:
Madmax199 said:
Oranoco said:
My old Fiesta RS Turbo used to chatter like mad. Being MAP sensor based there was no fueling issues and the Garret T3 was pretty barn door with it's engineering so no ill effects.

That chatter is bad long term because it happens at full load when the charge system is pressurized. At full load it should bypass (if there is a compressor bypass) -- but it's fine if it flutters at low-load and part-throttle because there is no pressure in the system to create any reversal or damage.

Here is what my car sounds like with twin dump valves. Flutters at part throttle (minimal pressure in the system) and fully bypasses at full load (when excessive pressure waves can revert back to the compressor blades).
Not true on these cars and turbos until you exceed 30psi. I've run 2 of these hybrid T3's at 18psi and 25psi respectively and my brother ran another at 22psi. It's widely accepted practice in Ford tuning circles.
I wouldn't say that it's not true that there is no long term negative effects from running without some form of compressor bypass. Are these effects something that will kill a turbo in short order like most people think? Not at all, and I am always preaching this on forums.

However, the long term and high pressure stress can't be argued, that's the whole reason why bypass valves were created. If not having a compressor bypass had zero effect on turbo life, Ford or Buick wouldn't have incorporated them in their later cars. Below is something I posted here just a couple hours before this thread, this will show you that I fully understand and agree that at moderate boost levels the stress is minimal and can be lived with. But that doesn't negate the cold fact that there is extra and unnecessary stress on the turbo from running this way.

Madmax199 said:
Although I'll be the first one to say that not running a compressor bypass valve will not kill a turbo short term (many turbocharged race cars don't bother running one). It does however have long term negative effect on the turbo bearings. Some old school turbo cars like the infamous Buick Grand Nationals came without a DV, they lasted several hundred thousand miles with no issue at stock boost. However, if the boost was increased like even a "stage 1", the No-DV approach took a toll on the turbos in a couple of years (I know because my friend has 4 and a half GNs in his driveway and backyard). The device is clever, works, and help reduce long term stress on the turbo. At the boost levels that I run on my TT for example, no DV would mean a turbo rebuild every year. Not worth it at all on a street car... unless you're sponsored by BorgWarner.
 
#17 ·
Not saying you don't understand overall as most of your argument is generally sound but I don't believe you understand these cars and turbochargers having spent 20 years on the Ford tuning scene and having a good friend who built up and owns one of the most respected tuners in Ford circles and another who designed and built the second ever Zetec turbo motor to Ian Howel (and now designs rolling roads). The Garret T2 and T3 turbos simply don't suffer with any ill effects until you start to run in excess of 30psi of boost. The T4 as found on the RS500 Cosworth however does require one to operate safely.

The Escort in particular doesn't like the use of a DV full stop as they cause running problems due to the air meter flap closing when pressure is dumped making the engine cutout
 
#18 ·
Just wanted to put this out there, another reason for chatter is using a stiff spring in the dv. If the spring tension alone doesn't allow the dv to open until say 15inhg of vac, at low boost lift off, there is little pressure to aid opening the dv enough to dump boost early, the turbo flutters. At high boost, the pressure acting on the dv along with vacuum alows the dv opens fully sooner so no flutter.
 
#19 ·
Madmax199 said:
I wouldn't say that it's not true that there is no long term negative effects from running without some form of compressor bypass. Are these effects something that will kill a turbo in short order like most people think? Not at all, and I am always preaching this on forums.

However, the long term and high pressure stress can't be argued, that's the whole reason why bypass valves were created. If not having a compressor bypass had zero effect on turbo life, Ford or Buick wouldn't have incorporated them in their later cars. Below is something I posted here just a couple hours before this thread, this will show you that I fully understand and agree that at moderate boost levels the stress is minimal and can be lived with. But that doesn't negate the cold fact that there is extra and unnecessary stress on the turbo from running this way.

Although I'll be the first one to say that not running a compressor bypass valve will not kill a turbo short term (many turbocharged race cars don't bother running one). It does however have long term negative effect on the turbo bearings. Some old school turbo cars like the infamous Buick Grand Nationals came without a DV, they lasted several hundred thousand miles with no issue at stock boost. However, if the boost was increased like even a "stage 1", the No-DV approach took a toll on the turbos in a couple of years (I know because my friend has 4 and a half GNs in his driveway and backyard). The device is clever, works, and help reduce long term stress on the turbo. At the boost levels that I run on my TT for example, no DV would mean a turbo rebuild every year. Not worth it at all on a street car... unless you're sponsored by BorgWarner.
THIS.

I've worked on several turbo designs for newer vehicles over the past 5 years including electrically actuated ones and you are spot on.

Something that isnt often known is the fact that older turbo's were usually able to take higher loads than the modern day ones, especially at the lower end of the spectrum. Shafts, bearings and in some cases even the casings are all setup for about 10-15% more than they are able to take according to their specific charts. This wasn't the case in the 80's or 90's.

Introducing flutter creates large spikes in the loading cycle of all of these components and will degrade them faster, though instant failure would only occur on a car creating levels of boost above what the turbo was designed to handle. On older turbos that had less optimisation than modern day units they may have failed slower, but given the modern life time is about 120,000 miles MBT its still going to last probably longer than you own the vehicle.

I wouldnt try it on a unit thats already done high mileage or hard duty cycles though.
 
#20 ·
JAY-13 said:
Madmax199 said:
I wouldn't say that it's not true that there is no long term negative effects from running without some form of compressor bypass. Are these effects something that will kill a turbo in short order like most people think? Not at all, and I am always preaching this on forums.

However, the long term and high pressure stress can't be argued, that's the whole reason why bypass valves were created. If not having a compressor bypass had zero effect on turbo life, Ford or Buick wouldn't have incorporated them in their later cars. Below is something I posted here just a couple hours before this thread, this will show you that I fully understand and agree that at moderate boost levels the stress is minimal and can be lived with. But that doesn't negate the cold fact that there is extra and unnecessary stress on the turbo from running this way.

Although I'll be the first one to say that not running a compressor bypass valve will not kill a turbo short term (many turbocharged race cars don't bother running one). It does however have long term negative effect on the turbo bearings. Some old school turbo cars like the infamous Buick Grand Nationals came without a DV, they lasted several hundred thousand miles with no issue at stock boost. However, if the boost was increased like even a "stage 1", the No-DV approach took a toll on the turbos in a couple of years (I know because my friend has 4 and a half GNs in his driveway and backyard). The device is clever, works, and help reduce long term stress on the turbo. At the boost levels that I run on my TT for example, no DV would mean a turbo rebuild every year. Not worth it at all on a street car... unless you're sponsored by BorgWarner.
THIS.

I've worked on several turbo designs for newer vehicles over the past 5 years including electrically actuated ones and you are spot on.

Something that isnt often known is the fact that older turbo's were usually able to take higher loads than the modern day ones, especially at the lower end of the spectrum. Shafts, bearings and in some cases even the casings are all setup for about 10-15% more than they are able to take according to their specific charts. This wasn't the case in the 80's or 90's.

Introducing flutter creates large spikes in the loading cycle of all of these components and will degrade them faster, though instant failure would only occur on a car creating levels of boost above what the turbo was designed to handle. On older turbos that had less optimisation than modern day units they may have failed slower, but given the modern life time is about 120,000 miles MBT its still going to last probably longer than you own the vehicle.

I wouldnt try it on a unit thats already done high mileage or hard duty cycles though.
Bad advice. Let them ruin their turbo, then we talk them into BT and we can enjoy some nice new BT threads on here :p
 
#21 ·
Beunhaas said:
JAY-13 said:
Madmax199 said:
I wouldn't say that it's not true that there is no long term negative effects from running without some form of compressor bypass. Are these effects something that will kill a turbo in short order like most people think? Not at all, and I am always preaching this on forums.

However, the long term and high pressure stress can't be argued, that's the whole reason why bypass valves were created. If not having a compressor bypass had zero effect on turbo life, Ford or Buick wouldn't have incorporated them in their later cars. Below is something I posted here just a couple hours before this thread, this will show you that I fully understand and agree that at moderate boost levels the stress is minimal and can be lived with. But that doesn't negate the cold fact that there is extra and unnecessary stress on the turbo from running this way.

Although I'll be the first one to say that not running a compressor bypass valve will not kill a turbo short term (many turbocharged race cars don't bother running one). It does however have long term negative effect on the turbo bearings. Some old school turbo cars like the infamous Buick Grand Nationals came without a DV, they lasted several hundred thousand miles with no issue at stock boost. However, if the boost was increased like even a "stage 1", the No-DV approach took a toll on the turbos in a couple of years (I know because my friend has 4 and a half GNs in his driveway and backyard). The device is clever, works, and help reduce long term stress on the turbo. At the boost levels that I run on my TT for example, no DV would mean a turbo rebuild every year. Not worth it at all on a street car... unless you're sponsored by BorgWarner.
THIS.

I've worked on several turbo designs for newer vehicles over the past 5 years including electrically actuated ones and you are spot on.

Something that isnt often known is the fact that older turbo's were usually able to take higher loads than the modern day ones, especially at the lower end of the spectrum. Shafts, bearings and in some cases even the casings are all setup for about 10-15% more than they are able to take according to their specific charts. This wasn't the case in the 80's or 90's.

Introducing flutter creates large spikes in the loading cycle of all of these components and will degrade them faster, though instant failure would only occur on a car creating levels of boost above what the turbo was designed to handle. On older turbos that had less optimisation than modern day units they may have failed slower, but given the modern life time is about 120,000 miles MBT its still going to last probably longer than you own the vehicle.

I wouldnt try it on a unit thats already done high mileage or hard duty cycles though.
Bad advice. Let them ruin their turbo, then we talk them into BT and we can enjoy some nice new BT threads on here :p
Hahahaha :lol: