I'm installing the STS kit and am trying to decide whether to hook up the boost reference line for the wastegate to the reference port on the compressor, or to the intake manifold.The install manual states to hook it up to the manifold (but they already do other things wrong so I can't trust them), and the STS guys (athenG et. Al.) said to hook it up to the manifold - so I'm sure things will be fine that way.However, Julian had said in a post that if you hook up the reference line post throttle-body you can run the risk of tearing the WG diaphragm from going in and out (that's what she said ) of boost - since the vacuum will be harshly sucking the thing closed.
The more exhaust you divert through the wastegate (the more you open the wasetgate door), the more you slow the turbo down and this is how you lower boost. This wastegate is pushed open or held closed by the wastegate actuator and a number of other variables such as exhaust pressure. The actuator is a boost actuated diaphragm inside a canister. Mar 21, 2013 A wastegate basically bypasses the turbine wheel to control your boost level so you'll need a boost reference. On a diesel it usually comes from the compressor housing. Very simple explanation ^. You should do some more research on how it all really works.
Is that true?The downside to running it off the compressor housing is that boost will read higher there than in the manifold (due to piping, FMIC, etc.) - resulting in the WG opening earlier, and that there might be a delay in closing the wastegate since the boost won't bleed off as much there as it would near the BOV?? Is that right?I searched, but as usual couldn't find much of anything. Actually, just doing some random searching on the interwebs it seems as though pre-throttle body is the way to go.
However, when the turbo is putting out 7 psi, the motor might only be seeing 6 psi. Post-TB reference will be less reactive (might get some spike), and pre-TB reference will be more reactive (most likely won't hit your target boost).Well, after some searching, it seems as though people have had no problems with a post-TB setup - their wastegate has lasted many miles. The best setup is probably to run it off of the intake tube just before the throttle body (like the instructions show), which would work well with the STS since it's already tapped there. For now though, I might as well give referencing it off the compressor housing a shot. Actually, just doing some random searching on the interwebs it seems as though pre-throttle body is the way to go.
However, when the turbo is putting out 7 psi, the motor might only be seeing 6 psi. Post-TB reference will be less reactive (might get some spike), and pre-TB reference will be more reactive (most likely won't hit your target boost).Well, after some searching, it seems as though people have had no problems with a post-TB setup - their wastegate has lasted many miles. The best setup is probably to run it off of the intake tube just before the throttle body (like the instructions show), which would work well with the STS since it's already tapped there. For now though, I might as well give referencing it off the compressor housing a shot.Let me know how you make out. I might do the same.
The only time I get some spike is when I'm doing some hard shifting but it only last for a couple of hundred RPM. It is not a big deal coz it very short live but if this help solve that then I might try it. Also I'm not sure if you'll have the same problem but I have a.5 bar WS spring and when using just the spring I only see 6psi. Not sure if its the BCS doing it but I can set Utec Boost Map to all 0 and couldn't go past 6psi with my.5 bar WS spring My worry is that if I use the Turbo as the reference then I might just see 4psi. Let me know how you make out. I might do the same.
The only time I get some spike is when I'm doing some hard shifting but it only last for a couple of hundred RPM. It is not a big deal coz it very short live but if this help solve that then I might try it. Also I'm not sure if you'll have the same problem but I have a.5 bar WS spring and when using just the spring I only see 6psi.
Not sure if its the BCS doing it but I can set Utec Boost Map to all 0 and couldn't go past 6psi with my.5 bar WS spring My worry is that if I use the Turbo as the reference then I might just see 4psi Will do. I was thinking the same thing last night: maybe the problem you guys were/are having with the TXS BCS not reacting fast enough causing a spike has something to do with this. I guess we'll see.I plan on just running off the WG spring just to get started (everything to 0 in the boost map). But like you said, coming from the compressor I probably won't be hitting much boost.
The bright side is that I won't have to run a vacuum hose the length of the carEDIT: And thanks SP for chiming in to add some credibility to this question. I would be interested to see what kind of pressure drop you see. Since you are referencing before all of the pressure drops through the piping, it will change based on rpm and flow rate. Maybe the change in flow rate won't effect anything but please post the logs when you do it!!!I am going home on leave this weekend, I can get you a starter map if you haven't already gotten one.I was able to get a hold of one - thanks though. Another one couldn't hurt I guessI bought the JeffSoftware LogAnalyzer as well, so I should be able to post up some sweet as screenshots.sarcasm. I'm HOPING to get this thing going by the weekend, but you never know what could go horribly wrong.
This article needs additional citations for. Unsourced material may be challenged and removed.Find sources: – ( January 2017) A boost controller is a device to control the level produced in the of a or engine by affecting the air pressure delivered to the pneumatic and mechanical actuator.A boost controller can be a simple manual control which can be easily fabricated, or it may be included as part of the engine management computer in a factory turbocharged car, or an aftermarket electronic boost controller. Contents.Principles of operation Without a boost controller, air pressure is fed from the charge air (compressed side) of the turbocharger directly to the wastegate actuator via a vacuum hose. This air pressure can come from anywhere on the intake after the turbo, including after the, though that is less common. This air pressure pushes against the force of a located in the wastegate actuator to allow the wastegate to open and re-direct so that it does not reach the turbine wheel. In this simple configuration, the spring's springrate and preload determine how much boost pressure the system will achieve.
Springs are classified by the boost pressure they typically achieve, such as a '7 spring' that will allow the turbocharger to reach at approximately 7 psi (0.48 bar).One primary problem of this system is the wastegate will start to open well before the actual desired boost pressure is achieved. This negatively affects the threshold of boost onset and also increases turbocharger lag. For instance, a spring rated at 7 psi may allow the wastegate to begin to (but not fully) open at as little as 3.5 psi (0.24 bar).Achieving moderate boost levels consistently is also troublesome with this configuration. At partial, full boost may still be reached, making the vehicle difficult to control with precision. Electronic systems can allow the throttle to control the level of boost, so that only at full throttle will maximum boost levels be achieved and intermediate levels of boost can be held consistently at partial throttle levels.Also to be noted is the way in which boost control is achieved, depending on the type of wastegate used. Typically manual 'bleed type' boost controllers are only used on swing type (single port) wastegate actuators.
To increase boost, pressure is taken away from the actuator control line, therefore increasing the turbo output pressure required to counteract the controllers leak-lowered pressure acting on the wastegate. Dual port swing type wastegate actuators and external wastegates generally require electronic boost control although adjustable boost control can also be achieved on both of these with an air pressure regulator, this is not the same as a bleed type boost controller. To increase boost with an external or dual port wastegate, pressure is added to the top control port to increase boost. When boost control is not fitted, this control port is open to the atmosphere.Manual boost control.
A simple manual boost controller. A small screw is located in the top of the aluminum body to adjust bleed rate.
This model is placed in the engine bay; however, the vacuum line could be extended to allow it to reach into the passenger compartment.A bleed-type manual boost controller simple mechanical and control to allow some pressure from the wastegate actuator to escape or bleed out to the or back into the system. This can be as simple as a T-fitting on the boost control line near the actuator with a small bleeder screw. The screw can be turned out to varying degrees to allow air to bleed out of the system, relieving pressure on the wastegate actuator, thus increasing boost levels. These devices are popular due to their negligible cost compared to other devices that may offer the same power increase.A ball & spring type boost controller uses the force of a spring acting against the boost pressure to control boost.
This is installed with one boost signal line coming from the intake somewhere after the turbocharger, and one boost signal line going to the wastegate. A knob changes the force on the spring which in turn dictates how much pressure is on the ball. The tighter the spring, the more boost that is needed to unseat the ball, and allow the boost pressure to reach the wastegate actuator. There is a bleed hole on the boost controller after the ball, to allow the pressurized air that would be trapped between the wastegate actuator and the ball after it is seated again. These type of Manual boost controllers are very popular since they do not provide a boost leak, allowing faster spool times and better control than a 'bleed type' boost controller.There are several different designs of ball-and-spring controllers on the market that range greatly in terms of cost and quality. Common body materials are brass and aluminum vary from inline to 90 degree designs. Another design aspect is the ball valve seat which is critical for performance stability.Generally a manual boost controller will not be located within the cabin of the vehicle as the lengthy vacuum piping run between the turbo/wastegate & controller can introduce response issues into the system.
It is possible to use two manual boost controllers at different settings with a solenoid to switch between them for two different boost pressure settings. A 3-port pneumatic solenoid. This solenoid allows interrupt or blocking of the boost pressure rather than just bleed type control.Electronic boost control adds an air control and/or a controlled by an.
The same general principle of a manual controller is present, which is to control the air pressure presented to the wastegate actuator. Further control and intelligent algorithms can be introduced, refining and increasing control over actual boost pressure delivered to the engine.At the component level, boost pressure can either be bled out of the control lines or blocked outright. Either can achieve the goal of reducing pressure pushing against the wastegate. In a bleed-type system air is allowed to pass out of the control lines, reducing the load on the wastegate actuator. On a blocking configuration, air traveling from the charge air supply to the wastegate actuator is blocked while simultaneously bleeding any pressure that has previously built up at the wastegate actuator.Control details.
A 4-port pneumatic solenoid installed to control a dual port wastegate controlled by a single controllerControl for the solenoids and stepper motors can be either or open loop. Closed loop systems rely on from a to meet a predetermined boost pressure. Open loop systems have a predetermined control output where control output is merely based on other inputs such as throttle angle and/or engine. Open loop specifically leaves out a desired boost level, while closed loop attempts to target a specific level of boost pressure.
Since open loop systems do not modify control levels based on MAP sensor, differing boost pressure levels may be reached based on outside variables such as weather conditions or engine coolant temperature. For this reason, systems that do not feature closed loop operation are not as widespread.Boost controllers often use pulse width modulation (PWM) techniques to bleed off boost pressure on its way to the reference port on the wastegate actuator diaphragm in order to (on occasion ) under report boost pressure in such a way that the wastegate permits a turbocharger to build more boost pressure in the intake than it normally could. In effect, a boost-control solenoid valve lies to the wastegate under the ´s (ECU) control. The boost control solenoid contains a needle valve that can open and close very quickly. By varying the to the solenoid, the solenoid valve can be commanded to be open a certain percentage of the time. This effectively alters the flow rate of air pressure through the valve, changing the rate at which air bleeds out of the T in the manifold pressure reference line to the wastegate.
This effectively changes the air pressure as seen by the wastegate actuator diaphragm. Solenoids may require small diameter restrictors be installed in the air control lines to limit airflow and even out the on/off nature of their operation.The wastegate control solenoid can be commanded to run in a variety of frequencies in various gears, engine speeds, or according to various other factors in a deterministic open-loop mode.
Or, by monitoring manifold pressure in a feedback loop, the engine management system can monitor the efficacy of PWM changes in the boost control solenoid bleed rate at altering boost pressure in the intake manifold, increasing or decreasing the bleed rate to target a particular maximum boost.The basic algorithm sometimes involves the EMS (engine management system) 'learning' how quickly the turbocharger can spool and how quickly the boost pressure increases. Armed with this knowledge, as long as boost pressure is below a predetermined allowable ceiling, the EMS will open the boost control solenoid to allow the turbocharger to create overboost beyond what the wastegate would normally allow. As overboost reaches the programmable maximum, the EMS begins to decrease the bleed rate through the control solenoid to raise boost pressure as seen at the wastegate actuator diaphragm so the wastegate opens enough to limit boost to the maximum configured level of over-boost.Stepper motors allow fine control of airflow based on position and speed of the motor, but may have low total airflow capability. Some systems use a solenoid in conjunction with a stepper motor, with the stepper motor allowing fine control and the solenoid coarse control.Many configurations are possible with 2-, 3-, and 4-port solenoids and stepper motors in series or parallel. Two-port solenoid bleed systems with a tend to be common on factory turbocharged cars.Advantages Since less positive pressure can be present at the wastegate actuator as desired boost is approached the wastegate remains closer to a completely closed state.
This keeps exhaust gas routed through the turbine and increases energy transferred to the wheels of the turbocharger. Once desired boost is reached, closed loop based systems react by allowing more air pressure to reach the wastegate actuator to stop the further increase in air pressure so desired boost levels are maintained.
This reduces turbocharger lag and lowers. Boost pressure builds faster when the throttle is depressed quickly and allows boost pressure to build at lower engine RPM than without such a system.This also allows the use of a much softer spring in the actuator.
For instance, a 7 psi (0.48 bar) spring together with a boost controller may still be able to achieve a maximum boost level of well over 15 psi (1.0 bar). The can be programmed to control 7 psi (0.48 bar) psi at half throttle, 12 psi (0.83 bar) at 3/4 throttle, and 15 psi (1.0 bar) at full throttle, or whatever levels the programmer or designer of the control unit intends. This partial throttle control greatly increases driver control over the engine and vehicle.Limitations and disadvantages Even with an electronic controller, actuator springs that are too soft can cause the wastegate to open before desired.
Exhaust gas is still pushing against the wastegate valve itself. This backpressure can overcome the spring pressure without the aid of the actuator at all. Electronic control may still enable control of boost to over double of the spring's rated pressure.The solenoid and stepper motors also need to be installed in such a way to maximize the advantages of.
For instance, if a solenoid is installed to control boost electronically, it should be installed such that if the solenoid fails in the most common failure mode (probably non-energized position) the boost control falls back to simple wastegate actuator boost levels. It is possible a solenoid or stepper motor could get stuck in a position that lets no boost pressure reach the wastegate, causing boost to quickly rise out of control.The electronic systems, extra hoses, solenoids and soforth add complexity to the turbocharger system. This runs counter to the as there are more things that can go wrong. It is worth noting that virtually all modern factory turbocharged cars, the same cars with long warranty periods, implement electronic boost control.