Manual and Electronic Boost Controller write up

[Bu11dogg2]

When it comes to controlling your turbo you have a few different options.

I STRONGLY recommend that you read this thread before doing any type of adjustment to your boost (http://www.newenglandsubarus.com/forums/showthread.php?t=3066)

The SAFEST, and best option is use an ACCESSPORT. The cost is higher, but if you're not a tuning expert it is your best option.

If you decide to use a Manual or Electronic Boost Controller you really need to know how to use it in conjunction with your ECU, Tune and modifications.

MBC = Manual Boost Controller

http://www.scionlife.com/tech/images/zpi_turbo_tc/mbc.gif

http://www.gnttype.org/techarea/images/wstgate.gif

http://t2.gstatic.com/images?q=tbn:_8QuBe8bPAcD3M:http://www.innovativetuning.com/catalog/images/HaProKit.jpg

An MBC is:

A very basic definition of Manual Boost Controller (hereinafter referred to as "MBC") is: a device that regulates the amount of air pressure applied to the intake manifold of an engine that is equipped with a turbocharger. So that we can understand why regulating (and increasing) the charged air pressure to the intake manifold is important, let's take a look at high-level overviews of both non-turbocharged, and turbocharged engines.


The MBC, which is essentially a valve with an adjuster on it, has two hoses. One hose is installed at a location that provides an accurate boost source. The location that provides an accurate boost source could be any number of places… a nipple on the compressor housing of the turbo, or another place in the intake system between the turbo and the intake manifold (basically, any location in the "charged" portion of the intake system). Different boost sources have different virtues, so turbo enthusiasts choose varying places to tap their boost source… we recommend that enthusiasts of the novice level follow the manufacturer's recommendation as to where to tap an accurate boost source. The other hose is installed at the Wastegate Actuator. In the picture below, the red arrow is pointing to the port on an actuator where the hose is attached. The Wastegate Actuator is the device that opens and closes the Wastegate, typically by means of an internal diaphragm, which cases an arm to move, which opens and closes the Wastegate. SOURCE (http://www.boostcontroller.com/display_page.php?i=19)

Types of Manual Boost Controllers

With ball-and-spring types, a spring-loaded ball is used to block this delivered boost "signal", until the desired boost level is attained. It is at this point, that the delivered boost pressure is strong enough to push the spring-loaded ball toward the spring and out of it's seat, allowing the signal to pass, and reach the Wastegate Actuator. The boost pressure then presses against the Wastegate Actuator's diaphragm, causing its arm to move, so that the Wastegate is opened. The opened Wastegate then allows the exhaust gases to divert away from the spinning turbine, thus preventing the turbo from boosting higher than the desired level.

The MBC is adjusted by turning a knob (or other adjustor), which varies the load on the spring inside the MBC. By adjusting it so there is more load on the spring, you are 'raising the boost" because more boost pressure is required to move the ball off its seat before the signal can pass to the Wastegate Actuator. By contrast, lessening the load on the spring allows the boost signal to more easily unseat the ball and continue on its voyage to the Wastegate Actuator, so by backing the adjustor away from the spring, you are "lowering the boost". The Joe P MBC (http://boostcontroller.com/index.php?category=4), and all Hallman Manual Boost Controllers (http://www.boostcontroller.com/index.php?category=5), are ball-and-spring type MBCs. SOURCE (http://www.boostcontroller.com/display_page.php?i=22)


With bleeder types, a valve simply "bleeds" off some of the boost pressure that it receives. It always allows some boost pressure to reach the Wastegate Actuator, but the boost pressure that the Wastegate Actuator receives is always less than the level of boost pressure in the charged portion of the intake system (or the boost level delivered to the bleeder-type valve) because this kind of MBC basically is a controllable boost leak. Since the Wastegate Actuator does not receive the "full boost signal", it only opens the Wastegate when the amount of boost that gets past the "leak" is sufficient to force it open. The bleeder-type MBC is adjusted by changing the size of the leak. Closing the leak down lowers boost level, because more of the boost signal then reaches the Wastegate Actuator, opening the Wastegate sooner. Opening the leak wider raises the boost level, as more boost is released to the atmosphere, as opposed to being delivered to the Wastegate Actuator as a boost signal; so the opening of the Wastegate is delayed.
SOURCE (http://www.boostcontroller.com/display_page.php?i=22)

Adjusting....

How is it determined what turbo boost level the MBC is set at, and what is the best level? The first part of that question is easy… the second part cannot be answered here. The set boost level is determined by means of a boost gauge. Do not depend on a factory boost gauge. Different car manufacturers use different methods by which to measure boost and display it to the driver. Modifications performed on the vehicle, including the installation of a MBC, may actually make the factory boost gauge display inaccurate readings. Only a good quality, after market boost gauge should be used.

As far as what boost level is best, you are on your own! This is not meant to scare or inconvenience you… but to make clear that it is the responsibility of the owner of the vehicle to research what level is best (and safe!) for their vehicle and their level of modifications. Two seemingly identical cars may have different optimal boost levels. Varying levels of modifications between cars also vary the optimum boost level. Online discussion forums that specialize in your model of car are one good place to investigate optimal boost levels. Never take one person's word for it. While they may be well intentioned, there is also lots of misinformation on the Internet. Always verify your research (over and over again).

There are other prudent modifications to the vehicle that can, and should be made in conjunction with installation of a MBC (and after market boost gauge) that will help maximize the resulting power gains of your vehicle and its safe operation. Freeing up the flow of both the intake and exhaust systems is always a benefit to turbo vehicles. Ensuring that there is always a sufficient fuel supply to go along with all the extra air crammed in thanks to the MBC is always a good idea. That may involve modifications such as a higher flowing fuel pump, higher capacity fuel injectors, or an after market fuel management system. The use of higher-octane fuel may also be prudent. SOURCE (http://www.boostcontroller.com/display_page.php?i=24)

[Bu11dogg2]

ECU Controlled Electronic Boost Controller
http://www.importimageracing.com/mm5/graphics/00000001/GrimmspeedebcsSubaru.jpg




User Controlled Electronic Boost Controller

http://t3.gstatic.com/images?q=tbn:gBw3bHYXPoT-4M:http://boostbitz.com/images/gpp-profec2.jpg

http://popeye.rty.nu/2004/apc.jpg



http://ribfeast.no-ip.com/boost_controller_install.jpg


Suppose you want to run 14PSI of boost, then a electronic boost controller should do this -- when the boost reaches 14.1PSI, the solenoid will connect the wastegate to the intake, causing the wastegate to open (since 14PSI is higher than the 7PSI required to open the wastegate)... the turbo will start slowing down, when it drops to 13.9PSI, the boost controller will then switch the solenoid and connect the wastegate to the atmosphere. This causes the wastegate to close since the atmosphere is 0PSI lower than the 7PSI needed to open the wastegate, and the turbo will start speeding up again. This happens rapidly and keeps boost regulated nicely at 14PSI.

Most boost controllers accomplish this by figuring out what percentage (or ratio) of the time the solenoid would connect the wastegate to the atmosphere vs. connecting the wastegate to the intake. This ratio is often known as the DUTY CYCLE, the duty cycle is directly related to the boost level.

Now this is the main function of the boost controller, but there is another benefit to running a electronic boost controller, and that is it will allow the turbos to spool up a little faster. How does it do this? Well, a wastegate might be designed to open at 7PSI, but it usually cracks open a little even before the pressure hits 7PSI. This will slow down spoolup of the turbo, causing it to hit 7PSI a little later. A good electronic boost controller would keep the wastegate shut for as long as possible, by using the solenoid to connect the wastegate to the atmosphere (0PSI) till the turbo gets really close to hitting the boost you want, only then it will start switching the solenoid back and forth according to the duty cycle. To determine how long to keep the wastegate shut, most electronic boost controllers use a number known as GAIN. If the gain is set too high, the boost could spike (the wastegate is held closed a little too long causing overboost), but if the gain is set too low, the spoolup is not as optimal as it could be. Getting the correct gain setting will give the optimal spoolup of your turbos. SOURCE (http://www.splparts.com/doc/tech/EBC.htm)


How to set up an electronic boost controller in manual mode


In manual mode, there are two numbers that has to be determined: DUTY CYCLE (sometimes also labelled as SET) and GAIN. The optimal gain number always depends on the boost level you want to run, if you are running very high boost, then you want the wastegate held closed for a longer time since it takes a longer time to reach the higher boost. So the first step is to determine the duty cycle:

1. Start off with a low DUTY CYCLE and GAIN setting.


2. In a higher gear (3rd or 4th), run the car to see what boost level the duty cycle corresponds to by watching what steady/stable boost level is reached. Increment the DUTY CYCLE with each run till you reach the boost level you want. Fine tune as necessary. If you notice boost spikes, then you have set the gain too high, you do not want spikes at this point since that makes it more difficult to see the steady/stable boost level.
The reason why you should use the higher gears is because in the low gears, things can happen too fast to figure out what the steady/stable boost level is. Now that you have figured out the duty cycle that will give you the boost level you want, the next thing to do is to work out the gain:


3. Make runs in lower gear (1st or 2nd), increment gain with each run till you see boost spikes. Then fine tune it till there is little or no boost spike. This is your optimum gain setting for that boost level.
The reason why you should use the lower gear now is because boost builds much quicker in the lower gears, so there is a higher tendency to boost spike.

When setting your boost controller, always have a passenger set the controller and watch the boost gauge for you, the driver should keep his eyes on the road!

Common problem


Sometimes if the gain is set too high, it may appear to have the same effect as the duty cycle. If you notice (especially in the higher gears) that you initially hit the boost level you want, but then it starts tapering off, then you might have set the gain too high and the duty cycle is not set correctly. Or you might have a boost leak... SOURCE (http://www.splparts.com/doc/tech/EBC.htm)

[Bu11dogg2]

Hybrid Boost Control (Thank you BG @ BrenTuning!)
http://i.imgur.com/Ik8XK.gif

It's the electronic solenoid (EBCS) plumbed in line with an MBC for full throttle duties only. This allows you to shape the part throttle curve and keep your failsafe for boost controller disabling if the car were to start to knock itself to death. While having rock solid MBC spike free boost control. Extra work and extra tuning but I think it's customer preference only. With a Grimmspeed solenoid and a good tuner (most don't put time or effort into part throttle boost response on the street after a dyno tune) you can map the best of both world benefits with the solenoid alone IMO.

I actually prefer the MBC alone feel on medium turbo car at part throttle.

Reasons it doesn't work:

-The 16bit 2L ecu has very little logic and correction for a EBCS type controller for super precise boost control. 32bit is a different story.
-It would disable the wonderful Si drive features at full throttle.
-If not mapped correctly there would be an unpleasant lump between part / full throttle.
-Modern day EBCS like Grimmspeed can be mapped just as well if your tuner puts in the time. No need for MBC.
-Works well with EWG, good part throttle with consistent full throttle as I'm never been a fan of EBCS noise on an EWG (chatter) when the EBCS does the duties alone.

[jwebsta32]

You pictured my mbc woooo

[itsmy04wrx]

Nice write up Randy, I'm diggin the avatar as well :lol:

[Bu11dogg2]

I didn't really write anything :lol: copy, paste, source :)

[Oscar_Meyer]

Ur "Ctrl" +"C" to "Ctrl" + "V" transistions are just phenominal...

Nice job touching on duty cycle & gain. From what I am understanding it can B used as a secret ingredient to really get what U want out of UR turbo..

[Bu11dogg2]

Yup :) low end power....

[Bu11dogg2]

I'll never go electronic again... way too much to fiddle with

[OMG.EVO]

I'll never go electronic again... way too much to fiddle with

I'm very interested in how this seems to be a split issue in the turbo community. Some people SWEAR by manuals, other people can't stand them.

From what I've seen... they both have their technical strengths and weaknesses.

How do you feel about ECU tuning w/ a 3-port solenoid? Essentially is a bare-bones version of EBC...

[Bu11dogg2]

Some tuners swear by an MBC.

I don't know know many people who use electronic only because it works differently with other cars, and not as well with ours.

[jwebsta32]

Chris from EFI likes the grimmspeed EBC.....DSG not so much

[Robk0000]

i had the grimmspeed 3 port on my gc, ecs tuned it first off and had no complaints. I was going to reinstall it on the 09 but bren said tuning is a bit more challenging.

[jwebsta32]

I still have it on my car but I am using a Hallman Pro because DSG didnt like it. I talked to EFI a while back and chris said he would change it back lol.

[BG @ BrenTuning]

i had the grimmspeed 3 port on my gc, ecs tuned it first off and had no complaints. I was going to reinstall it on the 09 but bren said tuning is a bit more challenging.

It's not more challenging per say - it's just a bit more time consuming and an unneeded mod on certain setups. They spool a bit better and can hold more boost up top. All 3 ports are not all created equal, but the Grimmspeed one is top shelf. It's based off a better design then the GM. But for most part, MBC works very well and there are alot of other tuners that agree with me here (Ed@EQ, Junior @ the shop, Matt @ DSG.)

Alot of tuners will just tune the 3 port well at WOT on the dyno yet undershoot the WG duty cycle based on target for part throttle and call it a day. Why? Well, because that part can be really time consuming. You could spend hours upon hours getting every target column right if you wanted too.

I have yet to find a setup I prefer an EBC on outside of small turbo, bigg(er) displacement car, or automatic cars. They surge and become a bit annoying and your MPGs can go down if you drive spirited as the car will always be in boost.

It's all tuner preference and there is nothing wrong with either route. Consult with your tuner for your goals and what they are comfortable with.

[OMG.EVO]

It's not more challenging per say - it's just a bit more time consuming and an unneeded mod on certain setups. They spool a bit better and can hold more boost up top. All 3 ports are not all created equal, but the Grimmspeed one is top shelf. It's based off a better design then the GM. But for most part, MBC works very well and there are alot of other tuners that agree with me here (Ed@EQ, Junior @ the shop, Matt @ DSG.)

Alot of tuners will just tune the 3 port well at WOT on the dyno yet undershoot the WG duty cycle based on target for part throttle and call it a day. Why? Well, because that part can be really time consuming. You could spend hours upon hours getting every target column right if you wanted too.

I have yet to find a setup I prefer an EBC on outside of small turbo, bigg(er) displacement car, or automatic cars. They surge and become a bit annoying and your MPGs can go down if you drive spirited as the car will always be in boost.

It's all tuner preference and there is nothing wrong with either route. Consult with your tuner for your goals and what they are comfortable with.


Yeah, I've seen the GM solenoid and I can tell you that those big ol' companies love to cost engineer ;) it's pretty cheap.

The rest of what you said I think pretty much sums it all up. The relaintionship between your tuner and your equipment is the prime factor.

A question I have for you - when you notice surge with an EBC/3port setup on cars that don't fall into those categories (small flow compressor/large displacement motor/slushbox) did you notice it at low RPM or high RPM? Assuming low?

[BG @ BrenTuning]

Yeah, I've seen the GM solenoid and I can tell you that those big ol' companies love to cost engineer ;) it's pretty cheap.

The rest of what you said I think pretty much sums it all up. The relaintionship between your tuner and your equipment is the prime factor.

A question I have for you - when you notice surge with an EBC/3port setup on cars that don't fall into those categories (small flow compressor/large displacement motor/slushbox) did you notice it at low RPM or high RPM? Assuming low?

When setup correctly, none. It just needs to be mapped accordingly.

I see temperature correction tables and turbo dynamics requiring some major fiddling on the GM solenoid to get right at all loads in the cold cold winters with the hot hot summers. I am a perfectionist so they need a good amount of work to dial in for both seasons accurately. I'll gladly tune one, however.

The Grainger type solenoids, such as the Grimmspeeds are far more precise here. GM is the lowest grade here.

A 3 port works as good as it's tuner, but IMO no such thing as 100% 3 port tune especially when you are on the pushing the turbo slightly out of its compressor map. 90-95% yes. Every tuner has a wildly different opinion here and neither is right nor wrong.

The best setup for someone ideally would be a grimmspeed in parallel with a quality MBC.

[OMG.EVO]

When setup correctly, none. It just needs to be mapped accordingly.

I see temperature correction tables and turbo dynamics requiring some major fiddling on the GM solenoid to get right at all loads in the cold cold winters with the hot hot summers. I am a perfectionist so they need a good amount of work to dial in for both seasons accurately. I'll gladly tune one, however.

The Grainger type solenoids, such as the Grimmspeeds are far more precise here. GM is the lowest grade here.

A 3 port works as good as it's tuner, but IMO no such thing as 100% 3 port tune especially when you are on the pushing the turbo slightly out of its compressor map. 90-95% yes. Every tuner has a wildly different opinion here and neither is right nor wrong.

The best setup for someone ideally would be a grimmspeed in parallel with a quality MBC.

I'm curious about the setup you suggest running the solenoid valve in parallel with an MBC. Am I being too literal and you meant in series? Because the setup I plan on going with, in some eventuality, is my Hallman (currently in use on my car) with a 3 port between it and the wg actuator. Is this the setup you were referring to or have I missed something?

I have a setup in my lab where I plan on bench testing the response of different setups (ex, mbc -> solenoid -> wg VS solenoid -> mbc -> wg) Maybe you have more experience here and can shed some light saving me valuable test time!

[BG @ BrenTuning]

I'm curious about the setup you suggest running the solenoid valve in parallel with an MBC. Am I being too literal and you meant in series? Because the setup I plan on going with, in some eventuality, is my Hallman (currently in use on my car) with a 3 port between it and the wg actuator. Is this the setup you were referring to or have I missed something?

I have a setup in my lab where I plan on bench testing the response of different setups (ex, mbc -> solenoid -> wg VS solenoid -> mbc -> wg) Maybe you have more experience here and can shed some light saving me valuable test time!

It must been a long day as I meant a series. Parallel would sure be interesting. You essentially get all the benefits of dialing in part throttle boost as aggressive or as soft as you want it to create a slow or fast ramp up. Yet have the precise rock hard boost control of an MBC at 100% throttle that follows the natural safe taper of the turbo. It's the best of both worlds.

[OMG.EVO]

It must been a long day as I meant a series. Parallel would sure be interesting. You essentially get all the benefits of dialing in part throttle boost as aggressive or as soft as you want it to create a slow or fast ramp up. Yet have the precise rock hard boost control of an MBC at 100% throttle that follows the natural safe taper of the turbo. It's the best of both worlds.

Okay, that sounds really great. I've always liked how a good MBC can work with a turbo to max out its efficiency.

Maybe the next product I do should be a combo unit bench tuned together so people don't have to deal with mix and match problems.

In your opinion, what is the proper setup? EBC between the MBC and WG, or the MBC between the EBC and WG? I can't really think of it being a huge difference, but speaking fundamentally the MBC would perform better if the EBC was after it (EBC between MBC and WG) due to a pressure drop through the orifice of the solenoid, since it is a pressure response device, whereas the solenoid is actuated binary on/off electronically.

Thoughts?

[WeldingHank]

he's pretty much talking about the Hybrid boost control that can be found in the EM section of nastioc.

I run a GM solenoid along with an MBC, the GMBCS controls boost below WOT. the, at 100% throttle I clamp the GMBCS shut and my MBC takes over. I absolutly love this setup and can reach peak boost (22psi) on my small 16g in 2nd gear. its quite the neck snap to say the least.

[BG @ BrenTuning]

It's a great setup.

Use a MAC style solenoid (grimmspeed) for best results.

[Bu11dogg2]

Updated with Hybrid info