The topic of cold-air intakes is frequently discussed. Some individuals vouch for them, saying they boost performance and make their car sound louder. Some claim that there is absolutely no distinction between a cold-air intake and a regular air intake. What then is the reality?
Your automobile may get louder and perform better if you install a cold air intake.
Your engine can take in more air and fuel by bringing in more cold air, which will result in higher power and performance. There are many various kinds of intakes that are available, and not all of them will function well with every type of car.
In This Article...
Does your automobile have louder exhaust tips?
Are Your Car’s Exhaust Tips Louder? The majority of the time, the answer is no. Drivers typically add a set of exhaust tips not to increase vehicle volume but rather for the improved aesthetic the tips offer. Drivers typically install a set of exhaust tips because of the improved aesthetic the tips offer.
Why does a turbo sound loud?
The turbo whistle is a sound that occurs as you advance up the rpm range because the turbocharger’s compressor is spooling up and speeding up, which is why it occurs at the boost threshold (when the turbo starts to kick in).
Is the turbo whistle normal?
The Check Anti Pollution System Message appeared the other day as I was driving my 2012 Renault Scenic 1.5 DCi, along with a minor loss of power. I was able to transport the car to the mechanic. He test-drove the car, and everything appeared to be in working order. I was told to continue driving normally and to turn around if the warning came on again. My wife discovered a turbo whistle when switching from second to third when I was picking up the car, so I took it back to the repair. I’ve been told that the turbo is to blame, and fixing it will cost 700. No smoke of any color has come from the exhaust, so I’m not really sure if the problem is with the turbo. Any suggestions?
There is essentially nothing wrong with a turbo; a “turbo whistle” usually signifies a worn-out and failing turbo bearing. Usually, the turbo bearing oil feed and oil return pipes are blocked with carbon from switching the engine off when the turbo is too hot, which is the cause for them failing since not enough engine oil is getting to the bearing to cool and lubricate it. It’s possible that fixing it will only require replacing these two pipes.
Downpipes do they alter sound?
The downpipe is the greatest obstruction in the exhaust system, and it greatly alters the car’s sound (from what others have said). Keep in mind that there is only about 5 HP in difference between a downpipe with and without a cat, so it might not be worthwhile to go catless. With a tune on a catback, you might be able to gain 510 HP (midrange); but, you’ll probably see larger increases with a high volume intake.
Turbo flutter: Does it harm the turbo?
You may have heard that turbocharged automobiles, especially those with huge turbos, large intercoolers, no blow off valve, and non-restrictive intakes, produce a lot of noise when the driver eases off the throttle. However, what exactly is this noise, does it harm your turbo, and how does it occur?
The StreetFX R32 GTR, which has a very massive GTX3582R turbo, is brought out, and we demonstrate the various sorts of flutter and discuss what is going on.
Since there is a lot of compressed air trapped between the turbocharger and the throttle body as a result, the only place it can go is back through the turbocharger and out into the intake if you do not have a blow-off valve (a device made expressly to release this pressure).
When the compressed air has nowhere to go, it tries to push against the wheel and causes the turbo’s rotational speed to drop quickly. Closed throttle flutter on current turbochargers is unlikely to result in a measurable reduction in turbocharger lifespan, but it can cause premature wear on your turbo.
In contrast to the older “bushed” turbos, almost all turbos developed for automobile usage in the last five years employ “ball-bearing” centers. Although older turbos can acquire significant play in the bushed center, ball-bearing turbos are less affected by this “push” movement. However, if your performance vehicle still has a bushed turbo, it might be time to upgrade.
Check out the images below to see how bush (sometimes referred to as sleeve or journal bearing) and ball bearing turbos differ from one another.
Note: During the video, we unintentionally stated “Blow off valve” when we meant “Throttle body” closing. This is plainly a mistake. A blow off valve “blowing off” extra boost serves to reduce the pressure in the intake during a closed throttle surge.
Note 2: We discuss the distinction between throttle flutter with an open and closed throttle. It was mentioned to me as an extra piece of information that closed throttle flutter is actually referred to as “reversion,” but open throttle flutter is more appropriately referred to as “compressor surge.” Despite the fact that they both technically constitute compressor surge and sound very similar, it is crucial to recognize the various circumstances in which they arise.
What causes Stutututu in automobiles?
These components, often known as diverter valves, are unrelated to boost control. You can hear the sound of diverter and blow-off valves when you swiftly depress the gas pedal. When the throttle blade (the flap that moves in response to the gas pedal) shuts, they release boost pressure. The blow-off valve allows the quickly moving air to escape since it has nowhere else to go. These components consist of a straightforward valve with an intake manifold vacuum reference and a spring to close the valve. The BOV opens when the intake manifold is vacuum-free (with no boost) in comparison to the rest of the intake system.
The BOV, not the wastegate, is responsible for the recognizable turbo sound (“pssst”; “sutututu”). Additionally, your car doesn’t need a BOV to generate that sound; typically, an aftermarket intake system will enable you to hear some unprocessed turbo noises because factory cars dump their boost via their diverter valves back into the intake, preserving the pssst sound.
What noise does a turbo flutter make?
One of the first things that comes to mind when people think about turbocharged cars is the sound of turbo flutter, that fluttering/chattering sound that occurs when the driver quickly backs off the throttle, such as when changing gear. Although that roar may let everyone know you have a turbo, it actually indicates a problem. Friends like turbochargers shouldn’t be put through hardships.
Turbo basics: exhaust energy used to create positive airflow (boost)
An air pump, or turbocharger, is a mechanical device that propels air. It accomplishes this by utilising the energy in lost exhaust gas to spin a turbine wheel on the compressor side, which then draws in cold, fresh air and pressurizes it for our engine to use on the turbine side. Our engine can generate greater power the more air we put into it.
Although the speed attained relies on the size of the turbo wheels, the entire process necessitates the shaft at the core of the turbocharger spinning extremely quickly. This speed is only increasing with newer designs and better efficiency. Because of their inertia, these high-speed spinning wheels exert a tremendous pressure on bearings and rotating parts that must function within precise tolerances when a sudden shift in speed is required of the system. It is more crucial than ever to keep everything operating as planned.
Compressor surge actually exists; it is not a myth created by Turbosmart to promote blow-off valves. We need to dig into the mechanics of turbocharging in order to properly describe it. We’ll try to keep things simple, so please be patient. The graph below displays the pressure ratio on the vertical axis and the airflow through a specific turbo on the horizontal axis. It is erroneous to believe that airflow and pressure are interchangeable; they are extremely different.
Every turbocharger has an efficiency zone, and whether it is a small or large zone depends on the use it was designed for. The ideal situation is to operate within this island of maximum efficiency, however it is susceptible to the engine’s configuration, its characteristics, and the road’s conditions.
The area shown in red in the aforementioned graph represents the region where efficiency is highest; here, pressure and airflow intersect at a location on the map where the turbocharger is operating “in the zone,” where efficiency is highest. Performance will suffer as a result of the turbocharger’s inconsistent operation in this zone.
Compressor spike in the past
The red line running along the left-hand side of the compressor map is seen in the graph below. The term “compressor surge” refers to the phenomenon of forcing the turbocharger to function to the left of the so-called “surge” line.
When your turbocharged engine is working hard, the turbocharger produces pressure while the engine consumes air (airflow) (boost). On this graph, these two things meet, and everything is operating as the turbo was intended to. Close the throttle, howeverfor instance, when shifting gears or decelerating quicklyand the pressure remains high due to the turbine wheel’s extremely fast rotational speed, but the airflow has ceased. This causes the pressure and airflow to “intersect” over the surge line when the pressure briefly peaks and the airflow essentially pauses, triggering the compressor surge of the turbocharger.
When a turbo is working in compressor surge, it makes a fluttering sound as the compressor “chops” through the air rather than forcing it into the engine. Love it or loathe it, it won’t improve the efficiency or dependability of your turbocharger.
A blow-off valve excels in this situation. Between the turbocharger and the throttle body, these are installed. The closer they are to the throttle body, the better because closeness boosts the response to reduce surge.
The blow-off valve’s main function is to stop compressor surge. When there is a sudden change in engine load from boost to vacuum, like when a throttle plate closes, it opens as soon as it can to achieve this. By keeping the valve open, the air flow in the charge pipe is ensured, which prevents a pressure spike andagain referring to the graph aboveallows the turbo to stay in the ‘zone’ without going over the surge line.
A good blow-off valve will be able to open quickly enough to prevent compressor surge and have enough flow capacity, while also being able to close and seal quickly once the throttle is opened again to increase boost and improve throttle response and acceleration.
Due to the low shaft speeds, the influence of compressor surge might be limited at low boost settings. Since the engine cannot open the valve at such low revs, many vent-to-atmosphere BOVs will still experience a very little amount of surge. However, compressor surge should be avoided as shaft speeds rise.
However, as technology and knowledge of it have advanced, blow-off valves are now a standard fitment from the manufacturer and simply vent the air back into the inlet system (recirculating it) in front of the turbo to be used again. Early factory turbo cars, which tended to run low-pressure turbos, often did not have blow-off valves at all.
However, it is commonly known that the factory-installed valves have restrictions. They are frequently composed of plastic, which ages and heat cycles brittlely and fractures. They rely on rubber diaphragms, which once again deteriorate and break down. They are unable to manage flow increases during large upgrades or even moderate boost increases.
Selecting the correct BOV
Maximum air flow is a consideration in the design of every Turbosmart BOV for performance and turbocharger dependability. They use light pistons to ensure quick response to eliminate surge, they are designed with a special Boost Balance system that ensures they cannot be overcome by higher boost levels, and they promote boost and throttle response equally by closing quickly to ensure turbocharger momentum is maintained, lowering lag and enhancing acceleration.
When selecting the ideal blow-off valve, it’s important to take into account the air-intake system’s size and performance requirements. The volume of pressurized air held by bigger intake systems (large intercoolers, charge pipes, etc.) requires a large blow-off valve to vent the larger volume of air, whereas the volume of pressurized air held by smaller systems may not require a large blow-off valve.
Kompact: created as a space-saving alternative to OEM parts where durability is a must.
Type 5: made to replace OEM components or special turbo setups with high flow/performance alternatives. Both street cars and race cars can benefit from Type 5 valves.
Maximum performance in a small, light-weight package: Vee-Port PRO. Perfect for high-performance applications when there is a lack of available space, like boosted motorbike or powersports applications.
Cars Don’t Have Blow-off Valves From Factory, So I Don’t Need One
In the early days of turbocharged vehicles, it might have been true that cars lacked blow-off valves. The majority of factory turbo automobiles at the time lacked a blow-off valve. These early turbocharged vehicles, nevertheless, were also operating at relatively low boost levels.
Most contemporary turbocharged vehicles come equipped with a blow off valve from the manufacturer. It does not, however, produce the distinctive sound of a vent-to-atmosphere blow-off valve since it cycles the vented air. Recirculating BOVs can also be referred to as bypass valves (BPVs). Standard BOVs/BPVs, however, are frequently fairly simple. In some cases, BOVs and BPVs are composed of plastic, have poor valve responses, and struggle to handle higher boost levels.
The next fallacy is brought on by the fact that these vehicles operate blow-off valves to prevent compressor surges.
Turbo Flutter is Harmless
A compressor surge is the cause of the fluttering sound that some turbocharged vehicles make when the throttle is abruptly closed, such as during gear changes.
We go into much more detail here to describe this quite complex issue. Flutter is the sound of a turbocharger trying to push air, to put it simply. but failing because of a closed throttle. Consequently, the load on the turbo’s bearings is greatly increased.
It can result in your turbo experiencing premature wear if it happens at greater engine loads or boost levels. In conclusion, a BOV stops turbo flutter by releasing the surge-causing air pressure.
Blow-off valves only vent to the atmosphere
This misunderstanding is most likely caused by the vent-to-atmosphere valve’s distinctive sound, which is a loud, piercing “Pssh. Although recirculating or plumb back valves are often used, you won’t hear them. A recirculating blow-off valve is a common feature of most contemporary factory turbo automobiles, as was already described.
A BOV is the Cause of a Boost Leak if it Leaks in a Smoke Test
Smoke tests pressurize the turbo system in an effort to identify boost leaks. Moreover, keep an eye out for where the smoke is coming from. This exam, though, does not simulate real-world driving situations.
Smoke tests frequently pressurize the BOV’s plumb backport, which is never the case while driving. Air leaks out of places that, under typical working circumstances, do not need to be sealed.
The soap test is another test type that is ineffective for determining whether a BOV is leaking. Similar to a smoke test, a soap test involves spraying soapy water over the BOV and the area around the turbo system. Since the system is also under air pressure, bubbles will develop where the air is escaping in the soapy mixture.
In these experiments, no piston style valve did not exhibit some leakage. They all do, and each for the ideal cause. The BOV’s piston needs a tiny bit of room to move, just like a piston inside an engine. The piston can move freely since there is only a tiny amount of space between the bore of the BOV and the piston.
There are no boost leaks as a result of this, and the tiny quantity of air that does get through would not affect boost in the actual world.