Custom Big Single Turbo To Custom Twin (S55) Turbo upgrade

[SlowE93]

The voltage is the constant, it will not change, but because they are in. Parallel the resistance remains the same so the current draw remains the same.

You are thinking voltage.
When wiring batteries in parallel voltage remains the same, available amperage would double.
If you wire batts in SERIES, available amperage remains the same but voltage will double.
Assuming 2 batteries are being used.

Now as far as 2 electronic wastegates go...
Resistance will most definitely be affected by wiring in parallel or series. It will NOT stay the same. Voltage supply will remain constant but at a different amperage/ current draw.

 

[Dumaurier7]

As stated before, when in parallel, resistance is halved, because there are now two coils , the halved resistance is now summed to that of the single coil’s original resistance , as it is a car the voltage remains the constant, it cannot change beyond an upper limit , so as the DME is concerned, it’s still driving one coil that is pulling the same amount of amperage. I do not anticipate any issue as I previously ran two BOV’s with the BW turbo, a Turbosmart electric BOV on the compressor housing and a Tial on the pipe activated by a MAC valve, both were wired in parallel on the same output and worked perfectly fine without the DME even knowing what was happening. What may be an issue is the actual performance of each actuator as they now both have to share the current delivered to them, but I would expect there would be room in the system design to compensate for this, if this proves problematic, I have a back up plan ( as stated before!) as always!

 

[wheela]

Well, I'm not going to argue basic DC circuit theory; everything I've presented is easily verifiable with a quick Google search.

Just to be clear, I'm not saying running a second actuator in parallel WILL cause a problem. But you should be aware that doing so will double current demand on whatever is controlling the wastegates.

I'm not very familiar with the EWG controls as I'm PWG, but another potential watch out is that's it's not uncommon for electric motor controllers in general to incorporate current monitoring as a way to detect a jammed motor, excess loading, etc. Even my Dyson vacuum has current monitoring to detect over-spinning if you completely obstruct the suction. I saw a guy in a Pure750 thread over on f87 post who was getting actuator codes only when trying to max out boost. I don't know the cause, but upon seeing that I wondered if it was the DME responding to excess current demand from the actuator pulling against much higher back pressure than the BMW engineers anticipated. IF that's the case (just conjecture on my part) such a code could be tripped at lower boost if the actuators are already pulling double the design current from the controller.

Let me just say that I think this is a very cool project! I'm excited that somebody is finally trying this, and I truly hope you're successful! I'm sure you'll be able to work through any snags you may encounter along the way. Looking forward to watching this project progress

 

[Dumaurier7]

I understand all that you put forward, but what you are not considering is that the DME will clamp the current as is done with injectors, because the resistance is now halved each motor can draw as much as they require, but the DME, will be monitoring the current draw and most likely throw a code., I will find out.! Most likely I will buy the controller now to make it available, as I am considering, blowing MOSFETS in my DME, but I am also looking at cloning because of bent pins a shit!. I an intellectual discussion

 

[SlowE93]

As stated before, when in parallel, resistance is halved, because there are now two coils , the halved resistance is now summed to that of the single coil’s original resistance , as it is a car the voltage remains the constant, it cannot change beyond an upper limit , so as the DME is concerned, it’s still driving one coil that is pulling the same amount of amperage. I do not anticipate any issue as I previously ran two BOV’s with the BW turbo, a Turbosmart electric BOV on the compressor housing and a Tial on the pipe activated by a MAC valve, both were wired in parallel on the same output and worked perfectly fine without the DME even knowing what was happening. What may be an issue is the actual performance of each actuator as they now both have to share the current delivered to them, but I would expect there would be room in the system design to compensate for this, if this proves problematic, I have a back up plan ( as stated before!) as always!

As my associate @wheela has said, I do hope all works out and I am sure that it will. Nice build for sure !
Now as far as the 2 coils being halved and keeping same current....
So if you have an amplifier and wire a 4ohm sub you get X amount of power. X = wattage.
Now wire two subs/voice coils in parallel.
We now have 2 ohms. Why does amplifier power increase ?
Sound level increases because you have doubled the cone area BUT....do a bench test. Current has also increased due to the resistance being halved.
We now ALSO have more power/wattage.

Lets simplify. A car has 2 headlights wired to a 10amp fuse (example only). Wire 2 more headlights in parallel on the same circuit. Are you saying we can trick the fuse wired into them thinking its still only running 2 headlights and not use any more amperage ?

Any time resistance is halved you get more current draw. You stated yourself the concern of "sharing" amperage.
I do understand what you are thinking, but with 2 items it is not possible. You would need 4 to = same resistance as 1.

Example. 4ohm single voice coil subs.
1=4ohm
1+1 wired in parallel = 2ohm
Get another 1+1 in parallel = 2ohm
Now wire those in series and get 4ohm so same amperage draw.
You need 2 more.....or 2) 8ohm subs in parallel =4ohm so same as 1 4ohm

So you need 2 more coils OR, if they make (which they do not to my knowledge) 2 coils of double resistance of the original factory equipment to run in parallel thus equalling the original resistance to 1.

Damn u @wheela I don't like showing this side of me

 

[SlowE93]

I understand all that you put forward, but what you are not considering is that the DME will clamp the current as is done with injectors, because the resistance is now halved each motor can draw as much as they require, but the DME, will be monitoring the current draw and most likely throw a code., I will find out.! Most likely I will buy the controller now to make it available, as I am considering, blowing MOSFETS in my DME, but I am also looking at cloning because of bent pins a shit!. I an intellectual discussion

What do you mean it will clamp the current ? How is it accomplishing this ?
Are you saying it puts out a specific/steady current ?

 

[Dumaurier7]

As my associate @wheela has said, I do hope all works out and I am sure that it will. Nice build for sure !
Now as far as the 2 coils being halved and keeping same current....
So if you have an amplifier and wire a 4ohm sub you get X amount of power. X = wattage.
Now wire two subs/voice coils in parallel.
We now have 2 ohms. Why does amplifier power increase ?
Sound level increases because you have doubled the cone area BUT....do a bench test. Current has also increased due to the resistance being halved.
We now ALSO have more power/wattage.

Lets simplify. A car has 2 headlights wired to a 10amp fuse (example only). Wire 2 more headlights in parallel on the same circuit. Are you saying we can trick the fuse wired into them thinking its still only running 2 headlights and not use any more amperage ?

Any time resistance is halved you get more current draw. You stated yourself the concern of "sharing" amperage.
I do understand what you are thinking, but with 2 items it is not possible. You would need 4 to = same resistance as 1.

Example. 4ohm single voice coil subs.
1=4ohm
1+1 wired in parallel = 2ohm
Get another 1+1 in parallel = 2ohm
Now wire those in series and get 4ohm so same amperage draw.
You need 2 more.....or 2) 8ohm subs in parallel =4ohm so same as 1 4ohm

So you need 2 more coils OR, if they make (which they do not to my knowledge) 2 coils of double resistance of the original factory equipment to run in parallel thus equalling the original resistance to 1.

Damn u @wheela I don't like showing this side of me

Because an amplifier is a simple device that is designed to provide as much wattage as possible, I am assuming ( I could be wrong here!) that the DME will be monitoring thiss output and will limit the current draw accordingly.

 

[Dumaurier7]

What do you mean it will clamp the current ? How is it accomplishing this ?
Are you saying it puts out a specific/steady current ?

The same way a Stand alone ECU does when you specify peak and hold Injectors, the amperage is supplied at 2 to 2.5 amps to open the injector then clamped to 1.5 after.

 

[wheela]

Because an amplifier is a simple device that is designed to provide as much wattage as possible, I am assuming ( I could be wrong here!) that the DME will be monitoring thiss output and will limit the current draw accordingly.

If that's the case (that the DME monitors current and limits it) it could be a problem for actuator function, as the only way to limit current to a circuit with half the resistance is to cut voltage.

 

[Dumaurier7]

Yes, so as I said earlier the performance of each actuator may be negatively affected, for this reason and the fact that I do not know the exact architecture or underlying functions of the DME and because I don’t want to risk blowing MOSFETS and giving myself more problems, I’ll just go with the controller as it is the better choice.

 

[SlowE93]

The same way a Stand alone ECU does when you specify peak and hold Injectors, the amperage is supplied at 2 to 2.5 amps to open the injector then clamped to 1.5 after.

I would need the schematics of said unit but I would think it does this knowing the specific resistance/load that it will see which you are changing. Halved resistance simply does not equal a whole again. It is halved. Like I explained wiring subs in parallel and then series to equal whole again.
You do understand that a wire connected to a device won't have any actual current running through it unless there is a specific load/draw on the opposite end correct ?
A wire simply sitting there has no amperage. Current will not flow unless you close the circuit.
So to "clamp" at a specific amperage requires a specific load / resistance which once again, you are changing.

 

[SlowE93]

Sorry to derail thread but in my defense @wheela started it !
I'll go fuck off once again

 

[Jake@MHD]

If you think about it the S55's DME has no way to know exactly what each turbo is doing other, than the position of each actuator via the internal position switches. in my case, only one actuator will report position as per original design, but the second will mirror the positioning of the first.

I'm not talking about the DME knowing the position, I meant electrically powering it. You won't be driving both of them with the single driver on your DME. The S55 has a driver for each of them.

 

[Dumaurier7]

Post #130 already explains the plan.

I'm not talking about the DME knowing the position, I meant electrically powering it. You won't be driving both of them with the single driver on your DME. The S55 has a driver for each of them.

please read post #130.

 

[Jake@MHD]

Post #130 already explains the plan.

please read post #130.

Which controller is it?

 

[Dumaurier7]

Remember V=IxR! Resistance is only doubled when connected in series but is halved when connected in parallel just like when connecting speakers in a sound system, because there are two coils the resistance goes down so the current drawn will also go down, in fact when in this configuration the total resistance usually adds up to the resistance of one coil. Knowing how smart and bitchy the BMW DME is I have this in mind as a contingency plan!

Please follow the link.

 

[Jake@MHD]

Please follow the link.

I figured that was the one you meant. And how to you plan to control that controller? It requires a normal PWM input, which it then translates to control / positioning of the electronic WG.

 

[fstbtstr]

very cool thread! if I was OP, I would try to hijack some of the stock pwm outputs to control the second wastegate controller. Say, an exhaust flap control or an evap purge valve. RAM address for writing duty cycle to the exhaust flap pwm controller is probably easier to find (wasn't a problem for 98G0B, for instance) than evap control. Of course, this approach will require some custom DME code, but maybe just copying wg duty cycle to that address is going to be enough. might or might not need to change the exhaust flap pwm controller frequency depending on that ewg controller pwm frequency or just make a converter circuit.

 

[Dumaurier7]

I figured that was the one you meant. And how to you plan to control that controller? It requires a normal PWM input, which it then translates to control / positioning of the electronic WG.

By using the signal to the stock actuator as my car is an EWG F22..

 

[Jake@MHD]

By using the signal to the stock actuator as my car is an EWG F22..

This will not work. The signal to the stock actuator is a specific type of control signal / feedback loop for the E-gate (h-bridge driven, similar to a throttle body). The control box you linked needs to be driven w/ a simple square wave PWM, like what controls the solenoid for vacuum controlled exhaust flaps, etc.

Not trying to rain on your parade here, just don't want you to waste time going down roads that won't work.