The Profec E-01 thread

[markiii]

Guys first off I'd appreciate if we can keep this as a reference thread so let try and keep it clutter free, apart from genuine Q&A

thanks  s:wink: :wink: s:wink:  

Since putting my car back together I've been having issues with my boost controler (Profec E-01) not doing what it should.

I've also had discussion with a number fo you ref how it actually works, opinions varying from "it bleeds off boost to the atmosphere to mask teh true pressure from teh wastegate (as per a manual boost controller)" to "it simply shuts the wastegate connection completely so it never see boost uintil you want it to, and hence stays shut."


in my quest for a definative answer, I discovered teh following ; (Blatantly copied from another website)

How does a electronic boost controller work?
 
First, let us understand how a turbo works.  A turbo simply consists of an exhaust wheel and a compressor wheel connected together, exhaust gases from the combustion turns the exhaust wheel which in turn spins the compressor wheel.  The compressor wheel then crams more air into the intake, creating boost pressure.

If left alone, a turbo would just keep spinning faster and faster and could result in too much boost, which would cause engine components to fail.  To regulate the amount of boost, wastegates are equipped on all turbo-charged cars.  The purpose of the wastegate is to divert some of the exhaust away from the turbo (so it won't spin the exhaust wheel).  A wastegate is simply a spring loaded valve, this valve opens when the intake pressure reaches a certain pressure and diverts some of the exhaust away from the turbo.  Suppose the wastegate is designed to open at 7PSI of boost, then when boost reaches 7.1PSI, the valve opens and the exhaust from the cylinders are diverted away from the turbos, and the turbo starts to slow down.  When the boost drops to 6.9PSI, the wastegate closes and the turbo starts to speed up again.  This happens rapidly and keeps boost regulated nicely at 7PSI.

The pressure at which the wastegate opens is the base boost pressure, installing a boost controllers will allow you to run higher boost.  An electronic boost controller usually works using a solenoid (electronically controlled) valve.  A solenoid valve would have 3 ports (sometimes 1 is hidden inside the housing), and 1 port goes to the wastegate, the other port is hooked up to the intake, and the last port is left open to the atmosphere.  The solenoid can switch between connecting the wastegate port to the intake port, or connecting the wastegate port to the atmosphere port.

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.


Manual mode vs. automatic mode vs. fuzzy logic

Most of the modern higher-end electronic boost controllers have an automatic mode or fuzzy logic, where you simply enter the boost you want to reach, and the boost controller would automatically try to figure out the DUTY CYCLE and/or GAIN.  In certain cases (eg. twin-turbo setups), this logic might not work very well, and it would be necessary to use the manual mode.


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...

hmm

Here is word for word extracted from teh (utterly crap Profec Manual)

Manual Input Mode (Set)

This feature will allow teh user to input a boost setting for a custome boost curve. This feature requires the user to input boost controller solenoid duty cycle value and monitor the boost in teh display moe to see how much boost is increased at the inputted duty cycle. 0% will be the same as base boost or boost controller turned off. 100% will be the same as disconnecting teh wastegate signal line completely.

Start Boost

This feature is used to improve teh turbo spool up by holding the signal to teh wastegate which holds the wastegate completely closed until the bost reaches the start boost value. If the value is too close to the SET boost value, the boost will overshoot (boost spike). Set this feature 2.9psi less thanthe set boost value.

Gain

This feature is used to stabilise the boost by changing the control valves duty cycle. The larger the value the faster teh response will be and teh lower it is, teh response will be slower. If the value is set too high the boost will overshoot (boost spike)

Select this mode and input teh desired solenoid duty cycle.


So if I'm reading all of this correctly;

1. Set = the amountof time in percentage terms that the solenoid is open to generate a given boost level.

2. Start boost is the same as the GAIN definition in teh first illustration.

3. What the hell is GAIN as refered to be Greddy?

all thougts appreciated on all of the above.

  s:? :? s:?    s:? :? s:?

[philster_d]

Good article Mark,

but  I would avoid mentioning 14psi, the laymen may only see what may be a safe boost level and take nothing more from the article.

Fix it  s;) s;)  to say 10 and they will never know. And if one fool copies the detail then no harm will be done.

No problem to delete my post when you have digested it. I certainly didnt intend to cloud your thread.

Regards,
Philster.

[Tem]

1. Set = the amountof time in percentage terms that the solenoid is open to generate a given boost level.

2. Start boost is the same as the GAIN definition in the first illustration.

3. What the hell is GAIN as refered to be Greddy?

all thougts appreciated on all of the above.

I don't have the profec, but usually generic controllers have two basic values. Ratio means the target value, which is probably called set in the Profec. Gain means how fast/aggressive you're going towards it. Set the gain too high and you'll shoot over the target, then fall a bit below it and after few oscillations you finally achieve it. Set it too low and it just takes longer than necessary to reach it.

[markiii]

but by teh definition of Gain in teh 1st article thats seems to be what Greddy define as Start boost?

would you agree?

[peppyuk]

I had one of these in my celica. IIRC start boost should be set a couple of PSI lower than the boost you want to run as the controller will hold the wastegate closed until you hit the start boost level after which it will let some pressure to the wastegate to open it up, the idea being to get upto max boost quicker.

I was never happy with the auto setting so spent ages messing around with the different settings and ended up with the boost coming in really hard and pretty early and it held within 16.8-17.2 PSI all the way to the red line.

It was a while ago but if anyone wants a hand setting one up around this part of the world I'll be willling to help.

[kanujunkie]

my brain asleep at the mo but just a point on how a turbo works to help explain it better. Corky Bell's book on turbochargers explains the turbo as an AIR PUMP, the air pump does exactly what it says, it'll pump the air into the system until a given point. The point at which the air pump ceases to be able to provide more power is when it reaches 70% of the energy going into the engine, this is the point at which the engine has taken the fuel and air that is entering the engine and burnt it. The hot gasses and potential energy leave the engine and up to 70% of that can be used by the turbo to compress the air reentering the engine.

The next thing to remember is the name of the unit. We all seem hell bent on calling it a turbo but in a car it propper name is a turbocharger, but that is also technically incorrect. The propper descriptive name should be a turbine compressor. The turbine section of the unit turns based on the hot gasses passing over the wheel, that wheel is connected to a shaft and in turn connects to a seperate unit, the compressor. This compressor wheel then takes air in, compresses it and passes it on to the intake gallery.

heres an example of the inside of a turbo



1)The compressor
2)The turbine
3)The interconnecting shaft.oil lubricated and running on bearings this is a seperate unit to the turbine and compressor.


Now to the discussion on the wastegate control solenoid.

I've got to put my hands up and say i was wrong on how i thought this worked, it does bleed pressure to atmosphere.  We need enter the world of theory here as we have no idea on how it actually works, only speculation. SteveJ is right though, the unit is not only a switch, but a pressure regulator. What do we require to make it work? we need to satisfy the requirements we need. As the turbo accellerates towards it set point(in Marks example he uses 14PSI) the turbo will want to run to the point at which its produceing more pressure than its set point, so what to do? you dont want to connect this pressure to the wastegate yet as this will just depressurise the turbo causeing the compressor to stall. So to solenoid valve enters a new scenario. The new scenario or mode is a pressure regulation mode. It bleeds excess pressure to atmosphere until the point when the throttle is cut. In the blink of an several things happen.

1) The compressor px for a fraction of time spikes
2) The MAP sensor senses this spike and returns the solenoid switch from its regulation mode to a switching mode, connecting the outlet px to the wastegate solenoid, this then opens the wastegate and dumps the turbine pressure
3)the sense pipe for the BOV senses a vacuum from behind the TB and trips the BOV dumping the inlet gallery px


does that sound right???

[markiii]

not to me, the description in my original post referes to switching the wastegate to atmosphere hence keeping it closed, nowhere does it refer to bleeding boost pressure to atmosphere

[GSB]

Here is word for word extracted from the (utterly crap Profec Manual)

Looks pretty simple to me... Of course tuning these things requires a very definite understanding of what your actions are actually doing.

It looks like a standard Proportional controller to me, it just needs to be tuned to match of the rate of pressure increase and decrease created by the spooling turbo and the operating wastegate...

Google "PID controller" for a little more info on how these things work. But expect to be confused by the jargon as people who write about these things tend to do so in a fashion that makes everyone else in the world feel like a numpty. Its just another way of keeping C&I bods like me employed at salary levels that are way above the work we actually do. If we made it out to be as easy as it sometimes is, we'd all be skint...

I suspect that half the problem is the different terminology being used for the same things and vice versa. Done in the right order, the setup will be pretty simple.

If your confused, and know you wil be, give me a shout in the morning..

[markiii]

cheers Grant I may well do that.

key part of the thread

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.

This says to me we aren't bleeding pressure to atmosphere but fooling teh wastegate actuator by switching it to atmosphere.

wouldn't you agree?

[kanujunkie]

not to me, the description in my original post referes to switching the wastegate to atmosphere hence keeping it closed, nowhere does it refer to bleeding boost pressure to atmosphere

aaahhh i see, your thinking of it the other way round from the wastegate point of view. The problem with that is it doesn't allow for pressure regulation and could result in massive boost spikes. The system must aim to maintain a boost level until the TB is shut off and just sealing the wastegate actuator wont do that, so you must think of it from the pressure side and mores to the point where the pressure is going

[markiii]

the pressure isn't going anywhere it's stick behind teh solenod.

likewise the thread seems to imply that the solenoid is constantly pulsing to acheive it's aim.

hence it will connect the wastegate to atmos until teh start pressure is acheived (Greddy term Start boost) article term GAIN. Once there it will contiually switch teh solenoid to alternate between wastegate to atmos and wastegate to pressure source to maintain teh setting.

are you interpreting it differently?

[kanujunkie]

are you interpreting it differently?

yeah i am, if you just connect the wastgate actuator to atmosphere then all your going to get is the outlet Px's rising beyond 14PSI (as per your example). The key in my mind is to remember when you want the wastgate to open and in between what do you do with the excess pressure that the turbo produces before you shut the TB

I kind of wish Steve is around to hear his interpretation on this at the mo

[GSB]

cheers Grant I may well do that.

key part of the thread

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.

This says to me we aren't bleeding pressure to atmosphere but fooling the wastegate actuator by switching it to atmosphere.

wouldn't you agree?

Exactly.

The wastegate is simply bypass valve that allows exhasut gases to pass around the turbine, rather than through it. In this way it can regulate amount of energy passed through to the compressor section and therefore set the maximum boost pressure at the compressor discharge. Its not an "on off switch" as many people think, and opening it up wont nessesarily dump all your manifold pressure as its commonly thought. In fact is quite variable in operation as it opens by an amount proportional to just how far over the set manifold pressure you've passed. By connecting its actuator to atmosphere, we are simply preventing it from doing its job, and allowing the turbo unit to build far higher pressures than it would otherwise achieve. Sadly though due to the higher pressures involved, when your electronics re-connect the actuator to the manifold pressure, it will fly full open, rather than feather in the way it was originally designed. to combat this it looks like Profec are using some kind of pulse width modulation to periodically apply pressure to the wastegate actuator, and then vent it away very rapidly. This will allow the control over the wastgate that gives fine control over boost pressures. It will vent some air to atmosphere, but not much. The venting isnt a direct part of the boost control process, its just used as motive power for the actuator.

What the boost controller is seeking to so is to replicate the action of the wastegate at a much higher pressure, and with finer control. By setting the gains etc in the controller, you are defining how much the wastegate opens when you go over pressure, Open to much and you'll upset fuelling and loose boost, which will then cause the wastegate to slam shut again, and build boost, and casue the waste gate to open, and loose boost... etc.etc....   Open to little and you'll overboost.  Its a delicate balance, not helped by the fact that wastegate actuators age rather quickly, with saggy springs and diaphragms.

[kanujunkie]

so in your theory then Grant your saying that the wastegate opens at varying points before you lift off the throttle, almost balancing the pressure?

if you are then i find that very hard to beleive as this is going to run toward the point where it could stall the turbine, the safer method is as per the manual boost controller, effectively bleeding the actuator signal

[philster_d]

And even the wastegate starts to open before you reach stock wastegate pressure. It is a progressive opening of a valve.

[GSB]

so in your theory then Grant your saying that the wastegate opens at varying points before you lift off the throttle, almost balancing the pressure?

if you are then i find that very hard to beleive as this is going to run toward the point where it could stall the turbine, the safer method is as per the manual boost controller, effectively bleeding the actuator signal

Not sure quite what you mean by the first part of your post here Stu, but what I'm aiming to describe is a controlled opening of the wastegate in order to accuratley control boost pressure. A common misconception with turbocharging is that the wastegate only opens when you close the throttle. This is not the case. It opens to some degree whenever the boost pressure in the intake system is high enough to overcome the spring resistance of the actuator. This allows the power input to the turbine to be moderated (or even "throttled" and allow only enough power to be transmitted to the compressor wheel to generate the pressure required. In this way it actually prevents compressor surge, rather than causing the turbine to stall.

If you think about it, with the actuator disconnected, the turbo will generate huge levels of boost pressure, far more than the engine can safely cope with. So it stands to reason that to maintain a moderate level of boost, the wastegate must actually be open to some degree almost all the time.

[kanujunkie]

my bad wording but yes that is what i meant, cheers for the info Grant, i was under the beleif that the wastegate closed till the driver lifted off the throttle but thinking about it theres no ability for it to know when that would happen anyway  s:roll: :roll: s:roll:    s:oops: :oops: s:oops:

[spynish]

Hi all,

I rescue this post to comment this thread has help me a lot tuning my Profec B Spec 2:

 m http://forums.evolutionm.net/showthread ... 826&page=1 m

Just read the whole thread to notice the LIMITER value has to be set at 4%, not at SET value minus 4% as stated on first post.

[Anonymous]

anyone have some pistures of engine bay with all sensors attachment points for PRofec?...any advice/tips/tricks for PRofec e-01 + e-manage blue combo? tahnks upfront

[Anonymous]

Not sure if this has been covered above there were some long posts above (To simplify i will use a manual controller as an example as all a digital does is the same thing but more stably), basicly the Actuator which controls the waste gate is pressurised from the inlet manifold after the Intercooler and on older cars like R5GT can be wound in and out to control boost by vacaum pressure in the Actuator as it works on a Diaphragm to move the wastegate (Sorry for spelling).

Now say the Actuator is a standard 7PSI unit (This is pretty standard 0.5Bar) the only way to get it to run more boost is to fool the actuator into thinking 14psi is only 7PSI, this is where the boost controller or bleed valve splices into the actuator vacaum pipes and allows a small amount of the Pressure to leek away, so the actuattor does not see that the inlet manifold is running 14psi it only receives a reading of 7psi and effectively lets the turbo overboost

[markiii]

Not sure if this has been covered above there were some long posts above (To simplify i will use a manual controller as an example as all a digital does is the same thing but more stably), basicly the Actuator which controls the waste gate is pressurised from the inlet manifold after the Intercooler and on older cars like R5GT can be wound in and out to control boost by vacaum pressure in the Actuator as it works on a Diaphragm to move the wastegate (Sorry for spelling).

Now say the Actuator is a standard 7PSI unit (This is pretty standard 0.5Bar) the only way to get it to run more boost is to fool the actuator into thinking 14psi is only 7PSI, this is where the boost controller or bleed valve splices into the actuator vacaum pipes and allows a small amount of the Pressure to leek away, so the actuattor does not see that the inlet manifold is running 14psi it only receives a reading of 7psi and effectively lets the turbo overboost

they acheive teh same end i.e fooling the wastegate but they don;t do teh same thing

[Anonymous]

They do do the same thing its just a digital controller is stable, accurate and allows for progressive boost buidling, variable boost across a rev range etc but the method it operates on is identical to that of the manual just more flexible, i was trying to simplify for understanding but the actual control of the actuator is an analogue approach rather than digital ie off or on and so allows for timed periods of running overboost, the wastegate is permanently open to a degree when the required boost is acheived as a turbo will effectively run infinite boost until it blows up without the wastegate bypassing some of the exhaust gasses around the turbine and limiting the speed at which the turbine rotates which in turn limits the inlet Compressor turbine speed (As they are on the same shaft) so reducing the pressure built.

For instance Digital controllers and manual controllers do not work on newer VAG engines as the actuator is activated by the ECU so you could set a controller to 28psi and it would still only run 7psi as the ECU over rides so they have to have a full remap to increase boost

[markiii]

the profec does not bleed off boost

[Anonymous]

Just read up on the Profec E01 the way it works is in principle the same but it just restricts the pressure allowed through the unit so 14psi comes in but 7psi is passed onto the actuator exactly the same but stopping the problems of idiots leaving the bleed pipe in the car cabin and it stinking of exhaust gasses   s:lol: :lol: s:lol:    s:lol: :lol: s:lol:  rather than feeding it back outside

[markiii]

yes but it doesn;t bleed anywwhere teh solenoid actuator just restricts whatts alowwed past it