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Electronic Boost Controller Comparison Chart

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Electronic Boost Controller Comparison Chart

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Old 05-03-11, 02:34 PM
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Electronic Boost Controller Comparison Chart

See my previous articles:

Sequential Turbos Demystified
FD Emissions control systems
FD cooling fan control system
Power FC Commander tuning

also, PM me about Power FC tuning group and notes.


Now, Perrin has a great introduction to boost control systems in their article Boost Control Explained. The OEM Mazda system uses a 2 port solenoid system and these aftermarket controllers mostly use a 3 port solenoid.

A common question asked is, “Which electronic boost controller should I get?” A lot of that comes down to price and preference. Believe it or not, aftermarket external electronic boost controllers tend to be pretty similar across makes and models. The components are similar, the control systems are similar, and the process of tuning the controller is also similar. Here I am presenting a comparison chart between the most common aftermarket electronic boost controllers currently available. To illustrate how similar many electronic boost controllers really are, the chart shows the different names each model uses for basically the same type of setting or function. For example, the AEM Tru Boost adjusts the wastegate opening pressure with the “SPr” aka “spring” setting. The Greddy Profec B Spec II adjusts the wastegate opening pressure with the SET GAIN aka “Start Boost” setting. Some controllers have functions completely missing: AEM Tru Boost doesn’t have a feedback setting, and the Blitz controllers do not have a wastegate opening pressure setting. Make sure you read the instructions of a particular boost controller before you go using it.

Although it is not a separate boost controlling device, I did put the Power FC into this chart because its boost control system is simple to adjust. I did not include other standalones such as Haltech and AEM EMS due to the complexity of setting them up. I also didn’t include the old Greddy Profec B and the older HKS EVC units (anything besides EVC-S) because they use stepper motors and that is not a common design anymore.

Basic Settings

Baseline duty cycle - this is a value usually from 0 to 99 which sets a baseline ratio of ON to OFF time for the solenoid. The boost controller rapidly cycles the solenoid. When the solenoid is ON, it is operating in a way that works to keep the wastegate shut . A higher value here corresponds to higher boost levels. You should start near 0 for this setting.

Wastegate opening pressure - This is the pressure at which the wastegate is allowed to open. If the current boost level is below this value, the gate will be stay shut. The higher you set this value, the more you will improve your spool, but at an increased risk of spiking. If this value is set too high it can lead to spikes or oscillations. You should start near 0 for this setting.

Feedback – Without getting too technical, this is a correcting feature of the boost controller which usually 1) improves initial spool and 2) reduces the amount that the boost falls off at high rpms . If this value is set too high it can lead to spikes or oscillations. Feedback is NOT the same as “self learning.” Self-learning features basically attempt to do the work of tuning the controller for you. Feedback is actually another parameter for you to tune and should not be confused with self-learning features. You should start by setting this value at or near 0.

Overboost protection – This should not be confused with an overboost warning. Many controllers will illuminate or sound an audible alarm, but the alarm itself just alerts the driver of a problem. The overboost protection could be a completely separate or a separate but related function to the overboost warning.
On an external EBC the overboost protection function of the controller will disable the solenoid once a certain boost has been exceeded. The controller disables the solenoid in an attempt to bring boost down to the wastegate spring pressure. Each controller implements the overboost protection feature in its own way so be sure to read the instructions carefully. This disabling of the solenoid will not protect your engine in the event of a serious mechanical failure such as a stuck wastegate or a melted wastegate hose. On factory ECU’s or standalone engine management overboost protection is accomplished usually with a fuel cut. Unlike a solenoid disable, a fuel cut will protect your engine in the event of a serious mechanical failure in the boost control system.

Temporary boost increase – usually this is called Scramble Boost. It’s a feature that allows you to raise the boost for some number of seconds. It is implemented differently across manufacturers. This is the kind of feature you would expect Paul Walker to use when he runs out of NOS. In reality not many people set this up.

Boost target – On controllers with a Self-Learning mode, this is the intended boost pressure that the controller will try to reach using a self-tuning process. Apex’I uses this setting differently. The AVC-R can utilize a boost target setting even when Self-Learning is disabled. On the AVC-R the boost target is used as part of the regular feedback system, unlike other controllers. The AVC-R’s implementation of a boost target is closer to what you find in many standalones (AEM EMS) or programmable stock ECU’s such as a Subaru stock boost control system. The Power FC has a boost target setting but its actual real-world use is more like a rough adjustment of the feedback system.
Attached Thumbnails Electronic Boost Controller Comparison Chart-ebc_comparison.png  
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Old 05-03-11, 02:34 PM
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Additional Features

Self-learning - This is NOT the same as a Feedback setting. This is a mode where the controller is supposed to figure out the settings for you, once you have picked a target boost and gone through a learning procedure. These features generally have mixed results at best. Personally I do not use self-learning modes because I feel that having someone competent adjust the controller manually will have a better final result.

Gear or Vehicle Speed based adjustment - This allows boost adjustments based on rpm or vehicle speed. Most commonly this is used as a form of traction control. These features are typically found on standalones but only a couple external electronic boost controllers have this kind of capability.

RPM-based adjustment - This allows fine tuning of duty cycle based on RPM. This could be used to keep boost steady at higher engine speeds.

After all that explanation here is the chart:



Note that some controllers combine two functions into one setting. For example, the Blitz controllers use the “Set” value as a boost target when in self-learning mode, but when in manual adjust mode the “Set” is a baseline duty cycle value.

Adjusting your boost controller

As a general strategy, when setting an electronic boost controller you should usually start with all the main settings (baseline duty, wastegate opening pressure, feedback) near 0. Configure your overboost protection setting. Now begin raising boost by alternate between increasing the baseline duty cycle and increasing wastegate opening pressure in small increments. Once you notice that the engine is slightly below the intended boost level, start adding in feedback until the target boost level is achieved and boost is relatively steady. From there you can make minor tweaks to the settings again. Every car is different but usually spikes or oscillations can be fixed by turning down the wastegate opening pressure or feedback settings.


In conclusion, the major external electronic boost controllers available today have the same basic system design. Some models have more or less features than their competitors, but all of them will get the job done as long as they are installed properly, tuned correctly, and used on a turbo system that is mechanically sound.
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Old 05-03-11, 03:33 PM
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Great thread thanks for posting it.
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Old 05-03-11, 04:07 PM
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FAQ'd. Thanks for posting another great resource.
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Old 05-03-11, 07:01 PM
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can you comment on the pfc boost control response capability for a single turbo? Does the wastegate stay closed until the last minute or it slowly opens thus slowing down response?
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Old 05-03-11, 07:04 PM
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What about the AMS 500 or the AMS 1000?
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Old 05-03-11, 07:23 PM
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Originally Posted by neit_jnf View Post
can you comment on the pfc boost control response capability for a single turbo? Does the wastegate stay closed until the last minute or it slowly opens thus slowing down response?
A boost controller that has a "wastegate opening pressure" setting (which the PFC does not) will have the most precise control over this characteristic. The more you try to maximize that initial spool up, the more you risk some spiking. Sometime you may actually want some intentional controlled spiking to give you that kick-in-the-*** feeling, but you have to make sure you are set up for it.

As far as the PFC specifically goes, you just have to play with the settings and maybe try different plumbing configurations. The best way to adjust the settings is to try raising and lowering the "Boost" and "Duty" settings, either one at a time or together. Log the wastegate duty cycle curve and log the boost curve after each change and see what combination of settings gets you closest to the response you prefer. On a single turbo you have different plumbing arrangements, different exhaust systems, and different wastegate springs that all affect controller response.

The biggest advantage of the PFC on a single turbo application is

1) cost--if you have a Datalogit, controlling boost with the PFC is very cheap. You just need a solenoid (the $30 MAC solenoid is popular) and hoses. I personally use the OEM Mazda 2-port wastegate solenoid on my own car just to demonstrate that it can be done. There are a ton of different ways to set up boost controller solenoids and solenoid plumbing.

2) integration with the rest of engine management--overboost fuel cut to protect you, boost changes from the commander, high/low boost switch capability if you wire it into your Datalogit

3) clean installation--plug a solenoid into the factory harness plug (or hardwire it) and that's it, no extra boxes or wires, uses the factory MAP sensor

4) datalogging capability--being able to see the exact relationship between boost and solenoid duty cycle

One of the main drawbacks though is the unconventional settings that Apex'i uses. It's like an oversimplified AVC-R. So you have tradeoffs to consider like any other decisions.

Originally Posted by Monkman33 View Post
What about the AMS 500 or the AMS 1000?
I'd have to look into that
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Old 05-03-11, 08:00 PM
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Originally Posted by neit_jnf View Post
can you comment on the pfc boost control response capability for a single turbo? Does the wastegate stay closed until the last minute or it slowly opens thus slowing down response?
I've been playing with the settings on mine and currently am getting 15psi at 3100 rpm with a gt35r t4 1.06.
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Old 05-03-11, 09:48 PM
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Very cool thanks for the post.
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Old 05-03-11, 10:28 PM
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No eboost2 being tested?
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Old 05-04-11, 12:10 AM
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Originally Posted by Slow Rotor View Post
No eboost2 being tested?
look at the chart again, very bottom

And I will say that i haven't used every single one of these controllers but I have the instructions for all of them. If anyone has any input or corrections please chime in.
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Old 05-04-11, 09:00 AM
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The AMS-500 and AMS-1000 boost controllers are definitely unusual designs. First of all, they are designed only for external wastegates. Like many external wastegate boost control plumbing configurations, they apply pressure to the top of the diaphragm (top wastegate port) inside the gate in order to help keep the valve closed. The side port of the gate receives dedicated manifold pressure and there is no T to the solenoid. I have used this type of plumbing before.



One solenoid applies pressure to the top port and another solenoid will vent it out. This may look weird but it is used in vacuum systems, automatic transmissions, and a lot of other hydraulic/pneumatic controls. For example, the ISC/BAC valve on the 1st gen 13B fuel injected Rx-7's actually has a vacuum solenoid and a vacuum vent solenoid kind of like that, rather than using a single duty controlled valve as on the 86+ 13B engines. The AMS solenoids themselves are the exact same style as the MAC solenoid used by AEM, Haltech, and Grimmspeed or the Denso solenoid used by HKS, Greddy, or Apex'i.

In terms of the controls for the AMS, they are different than anything else out there I've seen but still very simple. You set how much pressure will be applied to the top port of an external wastegate. This is how much pressure will be working against the spring; it is not a target manifold boost pressure that the engine will see. Once you set this pressure you can set what they call the "ramp rate" , which is basically how quickly the controller will try to achieve this target pressure working against the spring. The ramp rate is probably closest to a Feedback setting on other controllers. There really is no equivalent to the AMS 500/1000 "boost" setting. It is unique in that way. You have no direct control over the duty cycles for either solenoid and it doesn't seem to be intended for internal wastegates.

The AMS 1000 (not pictured above) seems to be aimed toward turbo motorcycles and has a lot of gear-based settings and a switchable output. It also uses an external MAP sensor which looks identical to the AEM MAP sensors and is probably a Delphi/GM part. Its basic control system is the same as the AMS 500 though.
Attached Thumbnails Electronic Boost Controller Comparison Chart-ams_boost_controller.png  
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Old 05-06-11, 09:16 PM
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Are there any other boost controllers I missed, besides maybe a few ebay brands?
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Old 05-06-11, 11:46 PM
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manual (ball/spring) vs electronic maybe?
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Old 05-07-11, 12:45 AM
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So, since I have a Powerfc and datalogit, all i need is a solenoid and I'm good to go? Time to do some searching!
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Old 05-07-11, 09:59 AM
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Originally Posted by neit_jnf View Post
manual (ball/spring) vs electronic maybe?
Well, I can comment on that some. It's basically a carburetor vs. multiport fuel injection type of debate.

When it comes to your typical ball-and-spring type manual boost controller, its biggest advantage is also its biggest disadvantage: simplicity. Simplicity means you usually turn a single **** (or whatever adjuster it has) one way for more boost or you turn it another way for less boost. There's not much of a learning curve and you just need to make sure you don't reverse the two hoses going to it. It's also cheap.

That simplicity also brings limitations for a manual boost controller. There is no overboost protection unless you rig up something machanical (popoff valve) or set up something on your engine management. You don't have precise control over the boost curve although in some cases you can try different springs to see how it affects the controller. The high end Hallman manual controllers allow you to adjust in the cabin which does eliminate that inconvenience. Manual controllers have no feedback or air temperature correction systems so in some cases it will be more prone to overboost in cold weather. However that completely depends on what you are comparing--some EBC's don't even have a feedback system (AEM Tru Boost) and only standalone ECU's and stock ECU's have air temperature correction. A properly configured manual controller will beat a poorly configured electronic controller.

So it's really a series of tradeoffs like any other decision with your car: It depends on what you are doing with the car and what your preferences are. Of course I like electronic stuff (especially data logging) but I have run manual controllers as well. There are many very fast high boosting cars running manual controllers. There isn't necessarily a "right" or "wrong" way to do things, but there are informed decisions and uninformed decisions.

Originally Posted by oppa637 View Post
So, since I have a Powerfc and datalogit, all i need is a solenoid and I'm good to go? Time to do some searching!
What is your setup? sequential twins, non sequential twins, single turbo?
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Old 05-07-11, 11:11 AM
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Sequential twins, with all emissions stuff deleted
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Old 05-07-11, 04:07 PM
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If you have sequential twins you don't need a Datalogit to use the PFC boost control, but it is helpful because you can use the logging to help you get the settings right. You could use the stock restricter + 2 port solenoid configuration, or convert to 3 port solenoids which are the same style you find in aftermarket controllers.

If converting to the aftermarket 3 port configuration, the solenoid you want is the MAC part # 35A-AAA-DDBA-1BA . It is also sold as the Haltech or AEM solenoid. You can find it on ebay here http://cgi.ebay.com/ebaymotors/Boost...Q5fAccessories .

you want two solenoids. That will replace the precontrol and wastegate solenoids which are bolted to the UIM from the factory. You can hard wire them to the harness or use a connector pigtail to make it plug-and-play. The connector you want is the 2 pin AMP/Tyco Econoseal II connector available from Ballenger Motorsports http://www.bmotorsports.com/shop/pro...oducts_id/1674. Sandro on this forum has done the conversion to dual MAC 3 port solenoids on his autocross car. I think he made a thread about it in this section.


so if you are ditching the factory solenoids the full conversion cleanly done on sequential twins you need

-- 2 -- 3 port solenoids, MAC brand is the least expensive. see attachment

-- 2 -- electrical connectors to make it plug-and-play. or hard wire see attachment

-- 4 -- 1/8" NPT --> 1/4" barb fittings . 2 fittings for each solenoid

-- a few feet of 1/4" hose (same as 6mm). I prefer to use fuel line or silicone hose. rubber hose doesn't handle heat well. see attachment for plumbing

-- some way to mount the solenoids. That's up to you.
Attached Thumbnails Electronic Boost Controller Comparison Chart-conn-85730.jpg.thumb_300x300_mat.jpg   Electronic Boost Controller Comparison Chart-mac_solenoid_pic.jpg   Electronic Boost Controller Comparison Chart-mac_solenoid_plumbing.jpg  
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Old 05-07-11, 05:21 PM
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you are awesomeeeeeee!!!
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Old 05-07-11, 09:18 PM
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Excellent stuff! BTW, did you make it to DGRR? I was hoping to track you down and chew the fat a bit!

A few bits I'd like to throw in -

- One boost controller that keeps popping up on occasions is the Greddy Profec-A. This boost controller uses a "Fuzzy Logic" technology, you're supposed to tell it you want boost pressure x and then make multiple runs until it "learns" the boost curve.

In theory, it's a great idea. Problem is, it only works if you have ROCK SOLID wastegate control, with NO creep. Most everyone I've seen use it has run into trouble, it can't figure out what's going on with the creep, freaks out, and throws the program out. I've also heard stories of bad overboost with it. It was a noble experiment but failed.

- I had an E-01 on my old FC back in the day. It's a REALLY cool design, you can tie it into multiple sensors, log stuff to an SD card, show all kinds of data on the screen, even tune the Greddy E-manage with it. Problem is, the screen on it SUCKS. It makes the screen on the original PFC Commander look great. It's actually the exact same screen as original Palm Pilots, a black/white LCD with a "glowing" backlight. Refresh and response on the screen is terrible, it's hard to see day or night, it's just not that great. I REALLY wanted it to work well, I bought the whole damn thing NEW when it first came out, spent a big chunk o'money.

- I have installed a few AEM Tru Boosts, the boost controller/boost gauge all in one. How it works/how well it works aside, the wiring for it is crap. Confusing wiring colors, no pre-made harnesses, it's REALLY cheesy. I had one with all sorts of problems due to wiring the wastegate solenoid wrong, the solenoid has 2 identical color wires going out of it and it's VERY weird how you hook it all up. Something going on my car needs to have a quality wiring harness, not something amateurish.

Really, when it comes to a boost controller, there are a few options -

- A basic electronic boost controller, like a Profec B. Easy to install and set up, easy to get running, not a ton of settings, and they just work.

- An advanced electronic boost controller, like the AVC-R. Gear and RPM based boost adjustment, lets you peak/hold and log, etc. - lots more to fool with and try and set up, but the end result can be rewarding if you put the time in to learn the system and tune it.

- The PFC boost control. Inexpensive and straightforward to tune, but does require you do some due diligence with the quality of your wiring and setup. Big props to Arghx for pioneering this system.

Regardless, the stock boost control desperately needs some help. Very early in the modification process you WILL need some form of boost control. People who ignore this will have spikes and creep which can and will result in killing a motor. You HAVE to have good boost control.

Dale
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Old 05-08-11, 01:02 PM
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Originally Posted by DaleClark View Post
Excellent stuff! BTW, did you make it to DGRR? I was hoping to track you down and chew the fat a bit!
I haven't been since 2006. There's always something coming up it seems. Maybe next year. I'm only 4 hours away.

Problem is, the screen on it SUCKS. It makes the screen on the original PFC Commander look great.
These devices were designed in the late 90s so it's no surprising they look like a 1st generation Game Boy. Aftermarket boost controllers aren't really a growth market anymore because these days you can reprogram the factory controller on new cars. So don't expect many hardware updates.
- I have installed a few AEM Tru Boosts, the boost controller/boost gauge all in one. How it works/how well it works aside, the wiring for it is crap. Confusing wiring colors, no pre-made harnesses, it's REALLY cheesy. I had one with all sorts of problems due to wiring the wastegate solenoid wrong, the solenoid has 2 identical color wires going out of it and it's VERY weird how you hook it all up. Something going on my car needs to have a quality wiring harness, not something amateurish.
AEM has some really low build quality electronics unfortunately. I have had my share of problems with them (their early AEM UEGO widebands were garbage). I like the AEM EMS standalone (as long as you don't have one of the crappy ones) but I avoid all their other stuff like the plague.

Really, when it comes to a boost controller, there are a few options -

- A basic electronic boost controller, like a Profec B. Easy to install and set up, easy to get running, not a ton of settings, and they just work.
Yes, there are a lot of owners who are best served by the very simple designs due to a very short learning curve. The Profec S is the replacement for the discontinued Profec B. The Profec B used a stepper motor like the older HKS EVC designs. The middle **** said "Balance" on it instead of "Gain" like on the Profec S. The simplicity of the Profec S results in many of the advantages of a manual boost controller.

- An advanced electronic boost controller, like the AVC-R. Gear and RPM based boost adjustment, lets you peak/hold and log, etc. - lots more to fool with and try and set up, but the end result can be rewarding if you put the time in to learn the system and tune it.
Yes but if you aren't going to use the advanced features IMO they are a waste.

- The PFC boost control. Inexpensive and straightforward to tune, but does require you do some due diligence with the quality of your wiring and setup. Big props to Arghx for pioneering this system.
It has its advantages and disadvantages as I've outlined above. The reason why nobody was using it before was because the instructions were garbage.

Regardless, the stock boost control desperately needs some help. Very early in the modification process you WILL need some form of boost control. People who ignore this will have spikes and creep which can and will result in killing a motor. You HAVE to have good boost control.
When you put the FD in context of newer turbo cars, the reason why you have this problem is because the factory ECU can't easily be reprogrammed. For example, if you buy a WRX and put a catless exhaust on it you will have many of the same problems that you do on an FD: overboosting, hitting fuel cut, engine knock and possible engine damage.

On a Subaru (or Evo/Ralliart) you can change out the restricter pill (just like an FD) or on some models adjust the wastegate arm in an effort to address the overboost. You could also install a new controller and eliminate the stock setup completely. But these days you can also buy an off-the-shelf commercial engine reflash solution (Cobb Accessport) or buy a cable and install a map you can find online on tuning sites. These maps will reprogram the stock boost controller so no pill modifications are required, or you can swap to an aftermarket 3 port boost control solenoid and eliminate the pill. Some newer internal wastegates don't even run off pressure, they are fully electric (Hyundai) or vacuum operated (BMW). So aftermarket controllers are useless.

If you have the stock boost control solenoids/pills and a PFC + datalogit you can still adjust the boost control but you may be better served by swapping out the solenoids such as the setup Sandro has been running on his autocross FD.
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Old 05-19-11, 11:06 PM
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I don't think I've ever posted this in the 3rd gen section, but below is a chart showing boost control solenoid duty cycle and boost. The graph illustrates one way that wastegate opening pressure, base duty cycle, and feedback are implemented into the control of the solenoid.



First, the solenoid runs at almost maximum duty cycle in an effort to keep the wastegate completely shut. In orange text you can see me pointing out the behavior as the wastegate opens: solenoid duty drops. Generally speaking, wastegate opening and solenoid duty have an inverse relationship: as duty goes down, the wastegate is allowed to open more. As duty goes up, the wastegate stays closed. As long as everything is set up right this relationship is independent of the wastegate type and the plumbing. Here the wastegate opening pressure here is about 7psi (in orange on the chart). If the wastegate opening pressure is set too high the boost will spike. The wastegate opening pressure is called SET GAIN on a Greddy Profec Spec II.

Looking right across the duty cycle curve (Green text), you can see that now that the wastegate opening pressure has been reached the duty cycle drops off and flattens out. This is where the baseline duty cycle comes in; it is the intial ratio of ON to OFF time as the solenoid cycles at a fixed frequency. As the solenoid cycles ON the pressure opening the gate may interrupted, or pressure may be applied to push the gate shut (depends on plumbing). On the Profec Spec II, the baseline duty cycle is called SET.

The feedback control (dark blue text) will modify that baseline duty cycle value to help keep the boost steady and reduce the amount of drop-off at higher rpm. If the feedback is too high, boost will spike or fluctuate excessively. On a Greddy Profec Spec II, the feedback is called GAIN.

The boost and duty cycle curve pictured above are not the most responsive in terms of spool up but they are relatively stable.
Attached Thumbnails Electronic Boost Controller Comparison Chart-greddy_duty.jpg  
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Old 05-20-11, 12:05 AM
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OH Questions....

Just curious. Whos using the AEM TRUBOOST ?????

I am running one currently, replaced my HKS EVCEZ which was great when I was running the twins, but sucked w/single turbo setup. Anyway, I was hopin some
fellas who were using the AEM TRUBOOST could give some opinions as well as:

1. How MAC VALVE ports ( 1,2, & 3) are routed.
2. Only one vacum line to open wastegate only, or 2 lines (open & shut).
3. Spring opening psi.
4. Duty cycle, what %.

Not to sound stupid, but I want to throw this in. Would most say they have normal amount of backpressure in exhaust manifold or more than average?

Food for thought and I'm feelin hungry.
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Old 05-20-11, 09:07 AM
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Originally Posted by arghx View Post
These devices were designed in the late 90s so it's no surprising they look like a 1st generation Game Boy. Aftermarket boost controllers aren't really a growth market anymore because these days you can reprogram the factory controller on new cars. So don't expect many hardware updates.
The E-01 actually came out in '02 or so, at that time the AVC-R was already out with a nice vacuum fluorescent display. Really no good reason they used that terrible screen. It's also a shame that it was so bad as it's a $500 or so boost controller!

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Old 05-20-11, 11:32 AM
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Amazing info, I vote to sticky this thread!

also, any xtra info, thoughts, experience with the HKS EVC Sport model? its based on the EVC 6 series.
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